Fact-checked by Grok 2 weeks ago

Paromomycin

Paromomycin is an derived from the soil bacterium rimosus var. paromomycinus, first isolated in the 1950s and primarily employed as the sulfate salt for treating intestinal protozoal infections, such as acute and chronic amebiasis, as well as for adjunctive management of hepatic coma by suppressing ammonia-producing gut bacteria. This broad-spectrum agent exhibits activity against Gram-negative and select , certain protozoa including Entamoeba histolytica and Giardia lamblia, and helminths like tapeworms, though its efficacy is limited to noninvasive intestinal pathogens due to minimal systemic absorption when administered orally. Paromomycin functions by binding to the of the subunit, thereby inhibiting bacterial and protozoal protein synthesis through disruption of initiation, elongation, and translocation steps. In regions endemic for , injectable formulations are utilized, often in combination therapies, to target species by similarly interfering with ribosomal function in the parasite. Approved by the U.S. for oral use in intestinal amebiasis and , paromomycin is generally well-tolerated with primarily gastrointestinal side effects like and , though parenteral administration carries risks of and akin to other aminoglycosides. Off-label applications include in immunocompromised patients and , with ongoing research exploring topical formulations for enhanced efficacy against parasitic skin infections.

Medical uses

Intestinal amebiasis

Intestinal amebiasis is a parasitic caused by the protozoan , which primarily affects the and can manifest as acute or chronic disease. Symptoms typically include watery or bloody , , cramping, , and tenesmus, though many infections remain asymptomatic with only passage in stool. Untreated symptomatic cases may progress to severe or complications like , making early intervention essential to eradicate the parasite from the intestinal . Paromomycin, administered orally, acts as a first-line luminal amebicide for both acute and chronic intestinal amebiasis, effectively targeting the parasite within the gut without addressing extraintestinal spread. The standard dosing regimen is 25–35 mg/kg per day, divided into three doses taken with meals, for 5–10 days to maximize tolerability and efficacy. As an , paromomycin inhibits protozoal protein synthesis by binding to the ribosomal subunit, disrupting essential cellular functions in E. histolytica. Clinical studies have reported cure rates of 70–100% for luminal amebiasis with paromomycin, highlighting its reliability in eradicating cysts and trophozoites. For example, a among individuals with endemic achieved 92% long-term microbiologic cure, while another single-dose trial yielded 88% resolution of symptoms and parasitologic clearance. These outcomes underscore paromomycin's role in preventing and , particularly in non-invasive cases. In comparison to , which excels at treating tissue-invasive amebiasis through systemic action but often requires a luminal agent to clear residual intestinal , paromomycin's negligible confines its effects to the gut, reducing the of systemic toxicity while effectively eliminating luminal forms. The Centers for Disease Control and Prevention (CDC) and (WHO) specifically recommend paromomycin for carriers in non-endemic areas to curb spread and for mild symptomatic intestinal amebiasis, often as monotherapy or adjunctive therapy. commonly causes mild gastrointestinal effects, such as and , which are self-limiting.

Hepatic encephalopathy

Hepatic encephalopathy (HE) is a neuropsychiatric complication of liver dysfunction, characterized by a spectrum of cognitive, behavioral, and motor disturbances ranging from mild confusion to . In patients with , the centers on , where impaired hepatic detoxification leads to elevated blood levels. Normally, produced from the breakdown of proteins by colonic and mucosal enzymes is absorbed into the portal circulation and converted to via the in periportal hepatocytes; however, in or portosystemic shunting, this process is disrupted, allowing to accumulate and cross the blood-brain barrier, inducing swelling, , and altered . Paromomycin serves as an adjunctive therapy in HE by targeting the to reduce . As a non-absorbable , it acts luminally in the colon to suppress urease-producing bacteria such as Proteus mirabilis and Klebsiella species, which hydrolyze and dietary proteins into ; this mechanism helps mitigate without significant systemic absorption. The standard oral dosing is 4 g daily in divided doses, typically for 5–6 days in acute episodes, and it is often combined with to enhance excretion through acidification of the colonic contents and promotion of . Clinical studies support paromomycin's efficacy in improving HE symptoms. In a randomized trial of 30 cirrhotic patients with portal-systemic , paromomycin at 1.5 g daily for 10 days significantly reduced blood levels (P < 0.001) and improved mental status as assessed by Conn's grading (P < 0.05) after 5 and 10 days of treatment. Comparative analyses with rifaximin in small cohorts (n=82) have shown equivalent reductions in and enhancements in psychometric performance, though rifaximin may offer advantages in some measures. For patients with chronic liver disease, long-term paromomycin use requires caution due to limited data on prolonged administration and potential risks if absorption occurs, such as nephrotoxicity or ototoxicity, particularly in those with ulcerative intestinal lesions. It is not FDA-approved for HE and is generally reserved for cases refractory to first-line therapies like lactulose, with monitoring for gastrointestinal side effects common in extended therapy.

Leishmaniasis

Leishmaniasis is a vector-borne protozoal disease caused by protozoan parasites of the genus Leishmania, transmitted to humans through the bites of infected female sandflies of the genus Phlebotomus or Lutzomyia, with clinical manifestations including visceral leishmaniasis (also known as ) and cutaneous leishmaniasis. Visceral leishmaniasis primarily affects internal organs such as the spleen, liver, and bone marrow, leading to severe systemic illness if untreated, while cutaneous leishmaniasis causes skin ulcers that can result in significant scarring and disability. Paromomycin, an aminoglycoside antibiotic that inhibits protein synthesis by binding to the 30S ribosomal subunit of the parasite, is used as an intramuscular injection for treating , particularly in endemic regions like India. The standard regimen in the Indian subcontinent is 11 mg/kg body weight per day administered intramuscularly for 21 days, achieving a final cure rate of 94.6%, which is noninferior to (98.8% cure rate). This formulation was approved by the Indian government in 2006 and added to the in 2007 for treatment. In regions with lower efficacy, such as East Africa, higher doses of 15-20 mg/kg/day for 21-28 days have been tested, often yielding variable results around 64-95%. The World Health Organization recommends combination therapies involving paromomycin for visceral leishmaniasis to improve efficacy and combat antimonial resistance, such as pairing it with sodium stibogluconate (20 mg/kg/day intramuscularly for 10 days) or miltefosine (oral for 14 days), which have demonstrated cure rates exceeding 95% in clinical trials in India and Eastern Africa. Parenteral administration carries a risk of ototoxicity, necessitating monitoring in prolonged or high-dose regimens. For cutaneous leishmaniasis, a topical ointment containing 15% paromomycin sulfate combined with 12% methylbenzethonium chloride is applied twice daily for 20 days, offering a noninvasive alternative with cure rates of 70-90% against New World species such as Leishmania braziliensis and L. panamensis. This formulation has shown efficacy comparable to antimonial injections in controlled trials, with approximately 80% cure rates in studies from Bolivia and Tunisia, though results vary by Leishmania species and lesion characteristics.

Cryptosporidiosis in HIV/AIDS

Cryptosporidium parvum is an apicomplexan protozoan parasite that causes cryptosporidiosis, a gastrointestinal infection manifesting as profuse watery diarrhea, severe dehydration, electrolyte imbalances, and significant weight loss, particularly in immunocompromised individuals such as those with advanced . In patients with CD4 counts below 100 cells/μL, the infection can become chronic and life-threatening without immune reconstitution, leading to malabsorption and prolonged hospitalization. Paromomycin, a nonabsorbable aminoglycoside antibiotic, is used to treat cryptosporidiosis in HIV/AIDS patients due to its luminal action in the intestine, where it targets the parasite with minimal systemic absorption. The typical dosing regimen is 500 to 700 mg orally four times daily for 14 to 28 days, often administered alongside antiretroviral therapy (ART), hydration, and nutritional support to optimize outcomes. This approach aims to reduce oocyst shedding and alleviate symptoms, though gastrointestinal side effects like nausea or worsened diarrhea may occur and complicate management. Clinical evidence supporting paromomycin's use derives from a meta-analysis of 11 studies involving over 300 HIV-infected patients treated between 1990 and 1996, which reported a 67% overall response rate in terms of symptom improvement and parasite reduction; however, complete cures were rare, with 58% of responders experiencing relapse. Two placebo-controlled randomized trials provided mixed results: one demonstrated modest but statistically significant reductions in diarrhea frequency and oocyst excretion after 21 days of treatment, while the other found no significant difference from placebo in patients with advanced HIV disease. These findings highlight partial parasitologic improvement but underscore the drug's limitations without concurrent ART. According to U.S. Department of Health and Human Services (DHHS) guidelines, paromomycin is recommended as an alternative therapy (rating CIII, indicating optional use based on limited evidence) for when the preferred agent is ineffective or not tolerated, always in combination with to achieve immune reconstitution as the cornerstone of management. Centers for Disease Control and Prevention () guidelines similarly endorse it as a supportive option, emphasizing that no antimicrobial provides consistent eradication in the absence of restored immunity. Prior to widespread ART availability, paromomycin offered only partial efficacy in reducing oocyst shedding and symptoms, with no reliable complete cures and frequent relapses due to persistent immunosuppression. Even with modern ART, challenges persist, including variable response rates and the need for prolonged therapy in non-responders, making immune recovery the primary determinant of long-term success.

Pregnancy and breastfeeding

Paromomycin has not been formally assigned a pregnancy category by the U.S. Food and Drug Administration, though it is often classified as category C based on limited human data and potential risks from its aminoglycoside class. Oral administration results in poor systemic absorption, with nearly 100% of the drug excreted unchanged in the feces, leading to minimal fetal exposure and low risk of teratogenicity for indications such as intestinal amebiasis and giardiasis. Animal studies have shown no evidence of fetal harm, but controlled human trials are lacking, necessitating use only when benefits outweigh risks. For giardiasis, paromomycin is considered a preferred treatment option during the first trimester of pregnancy due to its negligible systemic absorption, making it safer than alternatives like metronidazole. It is also deemed safe for treating intestinal amebiasis throughout pregnancy, with no reported teratogenic effects in available case series. However, parenteral administration for visceral leishmaniasis should be avoided if possible, as the drug crosses the placenta and carries risks of renal and auditory damage to the fetus, though no vertical transmission has been observed in treated cutaneous cases. In endemic areas, treatment for leishmaniasis may still be warranted during pregnancy when the maternal benefits clearly exceed potential fetal risks. Paromomycin is compatible with breastfeeding, as its poor oral absorption in the mother results in negligible amounts reaching breast milk and minimal transfer to the infant. No clinical studies have documented adverse effects in breastfed infants, and available data suggest it is unlikely to cause harm, though monitoring for mild gastrointestinal upset in the infant is recommended.

Adverse effects

Gastrointestinal effects

The most frequent gastrointestinal adverse effects associated with oral paromomycin therapy are abdominal cramps, diarrhea, nausea, vomiting, and heartburn. These effects typically occur in 10-20% of patients, with diarrhea reported in approximately 13.8% of cases in clinical evaluations of intestinal amebiasis treatment. Such symptoms are more commonly observed during treatments for intestinal amebiasis or hepatic encephalopathy due to the drug's luminal action in the gut. These gastrointestinal effects are generally mild, dose-related, and self-limiting, often arising from paromomycin's disruption of the intestinal . They tend to manifest with daily doses exceeding 3 g, as noted in prescribing . Management usually involves dose reduction or temporary discontinuation of the drug, along with supportive measures such as hydration to address . With prolonged oral use, paromomycin may lead to overgrowth of nonsusceptible organisms, including fungi, potentially resulting in secondary infections or altered nutrient absorption due to sustained microbiota perturbations. In such cases, appropriate diagnostic and therapeutic interventions are recommended to mitigate risks.

Systemic effects

Systemic effects of paromomycin are rare with oral administration due to its poor absorption from the gastrointestinal tract, which largely confines the drug to the intestinal lumen and minimizes systemic exposure. However, these effects can occur with parenteral administration, such as intramuscular injections used in leishmaniasis treatment, or in cases of malabsorption where increased absorption heightens the risk. As an aminoglycoside antibiotic, paromomycin shares toxicity profiles with its class, including potential damage to the kidneys and eighth cranial nerve. Ototoxicity is a significant concern, manifesting as hearing loss or vestibular dysfunction, with higher risk during intramuscular therapy for visceral leishmaniasis. In clinical trials, transient reversible ototoxicity was observed in approximately 2% of patients receiving injectable paromomycin, detected via audiometric monitoring, though long-term hearing loss was not reported. Nephrotoxicity, characterized by elevated serum creatinine and potential acute kidney injury, is also possible if the drug is systemically absorbed, particularly in patients with preexisting renal impairment; however, it remains uncommon with oral use and was infrequently noted in leishmaniasis studies. Neuromuscular blockade represents another rare but serious risk, potentially leading to respiratory paralysis, especially in individuals with myasthenia gravis or those receiving concomitant neuromuscular blocking agents. Hypersensitivity reactions, including rash and very rare anaphylaxis, have been documented, though they occur infrequently across aminoglycosides. For patients on prolonged or parenteral paromomycin therapy, monitoring guidelines recommend baseline assessments of renal function (e.g., serum creatinine) and hearing (e.g., audiometry), with periodic evaluations every 1-2 weeks during treatment and follow-up for 3-6 months post-therapy to detect early signs of toxicity. These precautions are particularly emphasized in special populations, such as pregnant individuals, where intramuscular use may pose risks of fetal renal and auditory damage despite oral administration's safety profile due to limited absorption.

Drug interactions

With other medications

Paromomycin, an aminoglycoside antibiotic primarily used orally with limited systemic absorption, exhibits few pharmacokinetic interactions but can potentiate pharmacodynamic effects when combined with certain drugs, particularly in intramuscular formulations for leishmaniasis where absorption increases. Concurrent use with other aminoglycosides, such as gentamicin, can lead to additive ototoxicity and nephrotoxicity due to shared mechanisms of cochlear and renal tubular damage, necessitating careful monitoring of renal function and auditory tests during co-administration. Similarly, combination with loop diuretics like furosemide heightens the risk of ototoxicity and nephrotoxicity through synergistic impairment of renal clearance and inner ear fluid dynamics. Paromomycin may enhance neuromuscular blockade when used with agents such as , especially in surgical settings, by interfering with acetylcholine release at the neuromuscular junction, potentially prolonging paralysis and requiring dose adjustments or reversal agents. This effect is also observed with other in polytherapy. By altering gut flora and possibly reducing absorption, oral paromomycin can decrease serum levels of certain drugs like and , potentially leading to subtherapeutic effects; monitoring serum levels is advised. Paromomycin may decrease the absorption of oral , potentially reducing its efficacy; monitor levels if co-administered. Paromomycin does not significantly interact with cytochrome P450 enzymes, as it undergoes minimal hepatic metabolism and is primarily excreted unchanged renally. However, caution is recommended with other nephrotoxic agents like , where additive renal impairment may occur, prompting dose adjustments and serial creatinine assessments. In leishmaniasis treatment, paromomycin is often combined with drugs like , showing indifferent interactions in vitro without synergistic toxicity, but polypharmacy requires vigilant dose titration and therapeutic monitoring to mitigate cumulative risks. Overall, while systemic exposure is low with oral use, clinicians should adjust doses in patients on multiple nephrotoxic or ototoxic medications to prevent amplified adverse effects.

With conditions or procedures

Paromomycin, as an aminoglycoside antibiotic administered primarily via the oral route, exhibits minimal systemic absorption under normal conditions, but certain patient conditions and medical procedures can alter its pharmacokinetics, potentially increasing the risk of toxicity such as or . In patients with , even small amounts of absorbed drug can accumulate due to reduced clearance, necessitating dose adjustments or avoidance, particularly for any parenteral formulations that may be used off-label in resource-limited settings. Guidelines recommend close monitoring of renal function in such cases, as the drug's elimination is primarily renal when systemically absorbed. Patients with myasthenia gravis or other neuromuscular disorders face heightened risks from paromomycin's potential to potentiate neuromuscular blockade, similar to other aminoglycosides, which can exacerbate muscle weakness and is particularly concerning during surgical procedures or anesthesia. This contraindication stems from the drug's interference with acetylcholine release at the neuromuscular junction, and use should be avoided in these populations to prevent respiratory paralysis or prolonged postoperative recovery. In individuals with inflammatory bowel disease, such as , paromomycin's efficacy may be compromised by altered absorption, while gastrointestinal adverse effects like diarrhea or cramping can be worsened due to underlying mucosal inflammation. Compromised bowel integrity in these conditions increases systemic exposure, elevating the risk of , and thus requires cautious use with potential dose reduction or alternative therapies. Overall guidelines contraindicate paromomycin in cases of known hypersensitivity to , as cross-reactivity can provoke severe allergic reactions including anaphylaxis. Caution is also emphasized for elderly patients and those who are dehydrated, as age-related declines in renal function or volume depletion can amplify toxicity risks even with oral administration. In these groups, baseline renal assessments and hydration status evaluation are essential before initiating therapy.

Pharmacology

Mechanism of action

Paromomycin, an aminoglycoside antibiotic, exerts its antimicrobial effects by binding with high affinity to the A-site of the 16S ribosomal RNA (rRNA) within the 30S ribosomal subunit in susceptible bacteria and protozoa. This interaction induces a conformational change in the rRNA, specifically displacing conserved adenine residues A1492 and A1493 toward the minor groove of the helix, which stabilizes the binding of near-cognate aminoacyl-tRNA and promotes misreading of the mRNA codon-anticodon interaction. As a result, translation errors lead to the production of defective polypeptides, causing premature chain termination and inhibition of protein synthesis. The drug's bactericidal and amebicidal actions stem from additional interference with ribosomal function, including inhibition of the formation of the initiation complex and blockage of translocation during the elongation phase. In bacteria, this disrupts the fidelity of translation, leading to accumulation of nonfunctional proteins that damage the cell membrane and facilitate further drug uptake, ultimately resulting in cell death. In protozoan parasites like Leishmania, paromomycin similarly targets the decoding site of ribosomes, reducing polyphenylalanine synthesis and increasing mistranslation frequency, with a dissociation constant (K_D) of approximately 1.7 × 10^{-3} M for Leishmania mexicana rRNA. Paromomycin demonstrates specificity for aerobic Gram-negative bacteria (e.g., Enterobacteriaceae), as well as protozoa such as Entamoeba histolytica, Leishmania species, and Cryptosporidium parvum, owing to its energy-dependent uptake mechanism that is impaired in anaerobes. It shows reduced activity against anaerobic bacteria and most Gram-positive organisms due to limited penetration of their cell walls. Resistance to paromomycin arises primarily through enzymatic modification of the antibiotic by bacterial or protozoan enzymes, such as , , or , which alter its structure and prevent ribosomal binding. Additionally, mutations or methylation in the (e.g., via enzymes like ) can sterically hinder drug attachment to the A-site, while may reduce intracellular concentrations. In , resistance involves upregulation of ribosomal proteins, vacuolar for drug sequestration, and stress response pathways to mitigate translation inhibition. Compared to other aminoglycosides like gentamicin or neomycin, paromomycin exhibits unique efficacy against certain parasites due to its stronger binding affinity for protozoan ribosomes, which more closely resemble bacterial than mammalian ones, allowing selective inhibition with lower toxicity to host cells.

Pharmacodynamics

Paromomycin exhibits a broad spectrum of activity against various enteric pathogens and protozoa, including Entamoeba histolytica and species of Leishmania. For E. histolytica, the minimum inhibitory concentration (MIC) typically ranges from 0.5 to 2 mcg/mL, enabling effective inhibition of protozoal growth at clinically achievable concentrations in the intestinal lumen. Against Leishmania species, such as L. donovani, IC50 values for intracellular amastigotes are generally in the low micromolar range (e.g., ~8 μM or ~5 mcg/mL). As an , paromomycin demonstrates concentration-dependent bactericidal activity, where microbial killing is optimized when peak drug concentrations reach approximately 10 times the for susceptible organisms. This property supports once- or twice-daily dosing regimens to maximize efficacy against aerobic and . Additionally, paromomycin produces a post-antibiotic effect, characterized by persistent suppression of bacterial and protozoal growth for several hours following brief exposure, which contributes to its overall antimicrobial persistence. Paromomycin shows synergistic effects when combined with pentavalent antimonials, such as meglumine antimoniate, in the treatment of ; studies demonstrate enhanced inhibitory activity against isolates. Its selectivity for microbial targets arises from structural differences in ribosomal binding sites, resulting in minimal disruption to mammalian ribosomes— is inhibited only at concentrations 10–15 times higher than those effective against bacterial or protozoal ribosomes.

Pharmacokinetics

Absorption and distribution

Paromomycin exhibits route-dependent profiles, with systemic exposure varying significantly based on the administration method. When administered orally, paromomycin demonstrates negligible systemic , with estimated at approximately 0.3%, primarily due to its poor uptake across the gastrointestinal mucosa. This limited confines the drug to the intestinal , where it exerts local effects against luminal pathogens, and over 99% of the oral dose is recovered unchanged in . In contrast, intramuscular administration results in near-complete , approaching 100% , with plasma concentrations typically achieved within 1 to 2 hours post-injection. For topical application, particularly to cutaneous lesions, systemic is minimal through intact (around 0.5% of the applied dose), though it can increase substantially (up to 91.5%) across compromised or ulcerated ; overall, the drug remains largely localized to the application site with low levels. Regarding distribution, paromomycin, when achieving systemic levels via intramuscular or topical routes, primarily remains in the compartment due to its hydrophilic nature and . The volume of is approximately 0.25 L/kg, reflecting limited intracellular typical of aminoglycosides. Protein is low, at less than 10%, which contributes to its availability for glomerular filtration. Tissue distribution is restricted, with measurable concentrations in extravascular fluids such as bone, , and , but extensive into organs like the liver or occurs only to a moderate extent. Paromomycin shows poor across the blood-brain barrier and into , even in the presence of meningeal inflammation, limiting its utility for infections.

Metabolism and elimination

Paromomycin undergoes no significant in the and is excreted primarily in its unchanged form. Following , over 99% of the dose is eliminated unchanged via the fecal route due to negligible systemic . In contrast, parenteral administration results in renal elimination as the primary route, with approximately 60% of the dose recovered in the , predominantly through glomerular without notable tubular or . More than 50% of the parenteral dose is excreted in the within the first 4 hours, and cumulative recovery reaches 60-70% over 72 hours. The elimination of paromomycin is 2-3 hours in individuals with normal renal function. This duration prolongs considerably in renal impairment, extending to 6.7 hours with clearance of 30-60 mL/min, 36.6 hours with 10-30 mL/min, and up to 68.4 hours in anephric patients. Systemic clearance is approximately 0.1 L/h/kg in adults, reflecting efficient renal handling, with no evidence of enterohepatic recirculation contributing to prolonged exposure. Paromomycin is moderately dialyzable, and its removal during necessitates dose adjustments in patients with end-stage renal disease to maintain therapeutic levels while minimizing accumulation.

History

Discovery

Paromomycin was first isolated in the early by researchers at & Company from the actinomycete rimosus var. paromomycinus, derived from a sample collected at Hacienda Tierradura in Miranda, . The producing organism, maintained in the company's culture collection, was cultivated under aerobic conditions in sterile aqueous nutrient media at temperatures between 20 and 35°C to yield the . It has also been reported as being produced by krestomuceticus. It was first manufactured in 1959 by Farmitalia Carlo Erba () under the name aminosidine. Initially referred to as catenulin or aminosidine, the compound underwent structural analysis that identified it as a novel closely related to neomycin, differing primarily by a hydroxyl group at the 6' position instead of an amino group. This elucidation, detailed in studies published around 1960, confirmed paromomycin's membership in the family through degradation and spectroscopic methods. The official name "paromomycin" was assigned in a 1959 U.S. granted to inventors Roger P. Frohardt, Theodore H. Haskell, John Ehrlich, and Mildred Penner Knudsen of & Company. Early testing revealed paromomycin's antibacterial potency, particularly against such as , , and species, with minimum inhibitory concentrations ranging from 1.56 to 25 µg/mL in nutrient broth assays. Activity was also observed against some , broadening its potential beyond bacterial targets. Preclinical studies further validated its broad-spectrum potential, demonstrating in animal models of bacterial infections and supporting its as a versatile with low toxicity at therapeutic doses. These findings laid the groundwork for subsequent development, emphasizing paromomycin's role in addressing Gram-negative pathogens and select parasitic organisms.

Clinical development

Paromomycin received FDA approval on March 24, 1969, as the oral sulfate formulation Humatin for the treatment of acute and chronic intestinal amebiasis and as an adjunct in the management of hepatic coma. The drug's anti-leishmanial activity was first recognized in the 1960s, prompting initial clinical trials for , though widespread evaluation was limited due to its primary focus on bacterial and protozoal infections. Development in the 2000s accelerated for , particularly through the intramuscular (IM) formulation, which was approved in in August 2006 following a phase III trial demonstrating noninferiority to for , with support from WHO collaborations. This IM paromomycin was subsequently included in the WHO Model List of in 2007. Topical formulations of paromomycin have also gained approvals in various countries, including and for caused by major, based on efficacy shown in phase III trials for old world species. The erratic pace of paromomycin's development stemmed from low profitability in markets for , where affected populations lack to incentivize pharmaceutical investment. The Drugs for Neglected Diseases initiative (DNDi) addressed this gap by leading clinical trials and combination therapies, such as paromomycin with , to enhance efficacy and access for in resource-limited settings. As of 2025, paromomycin remains on the WHO Model List of (23rd List, 2023), underscoring its role in treating . Ongoing trials continue to explore paromomycin combinations for HIV-related opportunistic infections, including and co-infections, aiming to improve outcomes in immunocompromised patients.

References

  1. [1]
    Paromomycin Sulfate Capsules, USP Rx Only - DailyMed
    DESCRIPTION. Paromomycin sulfate is a broad spectrum antibiotic produced by Streptomyces riomosus var. paromomycinus. It is a white, amorphous, stable, ...
  2. [2]
    Paromomycin | C23H45N5O14 | CID 165580 - PubChem - NIH
    A broad-spectrum antibiotic, it is used (generally as the sulfate salt) for the treatment of acute and chronic intestinal protozoal infections.
  3. [3]
    Interest in paromomycin for the treatment of visceral leishmaniasis ...
    Paromomycin is an antibiotic drug that was introduced for the treatment of visceral leishmaniasis in 2006. It is classified as a new aminoglycoside antibiotic.
  4. [4]
    Paromomycin - PubMed
    Oct 23, 2008 · Paromomycin is an aminoglycoside that is active against Gram-negative and many Gram-positive bacteria as well as some protozoa and cestodes.
  5. [5]
    Aminoglycosides: An Overview - PMC - NIH
    Like other aminoglycosides, oral paromomycin is poorly absorbed and may be used for the treatment of noninvasive amebiasis, cryptosporidiosis, trichomoniasis, ...
  6. [6]
    Paromomycin: uptake and resistance in Leishmania donovani - PMC
    The mechanism of antibacterial effect of paromomycin has been well documented, with the drug acting to inhibit protein synthesis through its interaction with ...
  7. [7]
    Efficacy and Safety of Paromomycin for Visceral Leishmaniasis - NIH
    Jul 24, 2021 · Paromomycin, an aminoglycoside drug, is frequently used for the treatment of visceral leishmaniasis. Despite limited therapies for visceral ...
  8. [8]
    Label: HUMATIN- paromomycin sulfate capsule - DailyMed
    Paromomycin sulfate is a broad spectrum antibiotic produced by Streptomyces riomosus var. paromomycinus. It is a white, amorphous, stable, water-soluble ...
  9. [9]
    Search Orphan Drug Designations and Approvals - FDA
    Generic Name: paromomycin. Date Designated: 02/11/2015. Orphan Designation: Treatment of cutaneous leishmaniasis (Old World and New World).Missing: uses | Show results with:uses
  10. [10]
    Amebiasis - CDC
    Jun 20, 2025 · Get the facts on amebiasis, a treatable disease caused by a parasite that can cause stomach issues.
  11. [11]
    Paromomycin Dosage Guide + Max Dose, Adjustments - Drugs.com
    Mar 25, 2025 · Usual Adult Dose for Amebiasis: 25 to 35 mg/kg/day orally in 3 divided doses with meals for 5 to 10 days.
  12. [12]
    DPDx - Amebiasis - CDC
    Oct 15, 2019 · The majority of infections restricted to the lumen of the intestine (“luminal amebiasis”) are asymptomatic. Amebic colitis, or invasive ...Missing: paromomycin | Show results with:paromomycin
  13. [13]
    Entamoeba histolytica Infection - StatPearls - NCBI Bookshelf - NIH
    This activity reviews the evaluation and treatment of amebiasis caused by ... [2] Luminal agents include the following: paromomycin, diiodohydroxyquin, or ...
  14. [14]
    Paromomycin therapy of endemic amebiasis in homosexual men
    Paromomycin produced long-term eradication of intestinal Entameba histolytica infection in 92% of all men evaluated. The rate of microbiologic cure among ...
  15. [15]
    [PDF] A Single Dose Treatment for Intestinal Amebiasis With Paromomycin
    ... paromomycin is effective in tbe treatment of intestinal amebiasis. A cure rate of 87.8,% was obtained. AH 11 adults receiving the 4 gm. dose level were cured.Missing: clinical | Show results with:clinical
  16. [16]
    Paromomycin in the Treatment of Mild-to-Moderate Intestinal ...
    Paromomycin in the Treatment of Mild-to-Moderate Intestinal Amebiasis | Clinical Infectious Diseases | Oxford Academic.
  17. [17]
    Amebiasis - Infectious Diseases - Merck Manual Professional Edition
    Treatment for symptomatic disease is with oral tinidazole, metronidazole, secnidazole, or ornidazole, followed by paromomycin or another medication active ...
  18. [18]
    [PDF] Drug Therapy of Amoebiasis - IRIS
    Paromomycin, which is poorly absorbed, appears to have little activity in the bowel wall in conventional dosage but, when the dose is increased to the high ...
  19. [19]
    Hepatic Encephalopathy - StatPearls - NCBI Bookshelf - NIH
    Jan 20, 2025 · Hepatic encephalopathy occurs due to liver failure or the redirection of blood flow away from the liver, such as in portosystemic shunting.Etiology · Pathophysiology · Evaluation · Treatment / Management
  20. [20]
    Antibiotics for the Treatment of Hepatic Encephalopathy - PMC - NIH
    Neomycin, vancomycin, paromomycin, metronidazole, and recently rifaximin, have been shown to be effective in acute and chronic therapy of HE.
  21. [21]
    Hyperammonemia - StatPearls - NCBI Bookshelf
    Abnormalities in the urea cycle or liver disorders may lead to increased levels of ammonia, which is then transported to the brain, skeletal muscle, and ...
  22. [22]
    Paromomycin Monograph for Professionals - Drugs.com
    Jul 22, 2025 · 25–35 mg/kg daily, in 3 divided doses, given for 5–10 days (usually 7 days). Symptomatic Intestinal Amebiasis or Extraintestinal Disease ( ...
  23. [23]
    Effect of rifaximin and paromomycin in the treatment of portal ...
    Rifaximin proved to be as effective as paromomycin even though baseline ammonia levels were higher in the rifaximin group.Missing: dosing evidence
  24. [24]
    Leishmaniasis - World Health Organization (WHO)
    Jan 12, 2023 · Leishmaniasis is caused by a protozoa parasite from over 20 Leishmania species. Over 90 sandfly species are known to transmit Leishmania parasites.This dashboard contains data... · Control of the leishmaniases · Kala-azar
  25. [25]
    Injectable Paromomycin for Visceral Leishmaniasis in India
    Paromomycin, an aminoglycoside antibiotic, has been shown to have a dose–response efficacy in the treatment of visceral leishmaniasis when administered ...
  26. [26]
    New Cure For Deadly Visceral Leishmaniasis (Kala-Azar) Approved ...
    Sep 11, 2006 · ... India (DCGI) has approved Paromomycin Intramuscular (IM) Injection for the treatment of Visceral Leishmaniasis (VL), the second most deadly ...
  27. [27]
    WHO approves new kala-azar injection | Patna News - Times of India
    May 24, 2007 · PATNA: Paromomycin intra mascular injection has been added to WHO Essential Medicines' List for treatment of kala-azar disease.
  28. [28]
    Paromomycin for the Treatment of Visceral Leishmaniasis in Sudan
    We therefore decided to test the efficacy of paramomycin for a longer treatment duration (15 mg/kg/day for 28 days) and at the higher dose of 20 mg/kg/day for ...
  29. [29]
    Leishmaniasis Treatment & Management - Medscape Reference
    Oct 23, 2024 · The WHO guideline for the treatment of visceral leishmaniasis ... dose, in combination with 7 days of oral miltefosine or 10 days of paromomycin.
  30. [30]
    Paromomycin and Miltefosine Combination as an Alternative to ...
    Sep 27, 2022 · PM treatment of 15 mg/kg/day for 21 days showed satisfactory efficacy in Asia but only 63.8% efficacy in Africa [9] with high variability. A ...
  31. [31]
    Topical paromomycin/methylbenzethonium chloride plus parenteral ...
    Topical paromomycin/methylbenzethonium chloride plus parenteral meglumine antimonate as treatment for American cutaneous leishmaniasis: controlled study.
  32. [32]
    Topical paromomycin for New World cutaneous leishmaniasis
    May 2, 2019 · Our study demonstrated the efficacy of these preparations against New World leishmanial species (mostly L. panamensis) with a cure rate close to 80%.Missing: ointment | Show results with:ointment
  33. [33]
    Topical Paromomycin with or without Gentamicin for Cutaneous ...
    Feb 7, 2013 · Intramuscular paromomycin cured visceral leishmaniasis in 95% of patients in India but was less successful in those with cutaneous leishmaniasis ...
  34. [34]
    Topical 15% Paromomycin-Aquaphilic for Bolivian Leishmania ...
    Sep 27, 2018 · Topical application of 15% paromomycin in Aquaphilic cured 77.5% of 40 patients with Bolivian Leishmania braziliensis cutaneous ...
  35. [35]
    Cryptosporidiosis: Adult and Adolescent OIs - Clinical Info .HIV.gov
    Jan 18, 2023 · Paromomycin in high doses is effective for the treatment of cryptosporidiosis in animal models. A meta-analysis of 11 published studies of ...
  36. [36]
    Treating Opportunistic Infections Among HIV-Infected Adults ... - CDC
    Two randomized controlled trials have compared paromomycin with placebo among patients with AIDS and cryptosporidiosis; modest, but statistically significant ...
  37. [37]
    Paromomycin: No More Effective than Placebo for Treatment of ...
    Three paromomycin recipients (17.6%) versus 2 placebo recipients (14.3%) responded completely. Rates of combined partial and complete responses in the ...
  38. [38]
    Paromomycin for cryptosporidiosis in AIDS: a prospective ... - PubMed
    Paromomycin treatment resulted in improvement in both clinical and parasitologic parameters in cryptosporidiosis in AIDS.
  39. [39]
    Paromomycin Use During Pregnancy | Drugs.com
    Mar 25, 2025 · -This drug is poorly absorbed orally; it is not likely to reach the bloodstream of the infant or cause any harmful effects in nursing infants.
  40. [40]
    Survey of Obstetrician-Gynecologists about Giardiasis - PMC - NIH
    Paromomycin is considered the safest to use for treatment in the first trimester because it is poorly absorbed from the intestine and nearly 100% is excreted ...
  41. [41]
    Clinical Care of Dientamobea fragilis - CDC
    Feb 21, 2024 · Dientamobea fragilis infections are often asymptomatic and require no treatment. If symptoms occur and the parasite is the only organism ...Missing: amebiasis | Show results with:amebiasis
  42. [42]
    Treatment of Giardiasis - PMC - PubMed Central - NIH
    Paromomycin is generally considered safe because it is poorly absorbed from the intestine and excreted almost 100% unchanged in the feces. Therefore, little if ...
  43. [43]
    Visceral Leishmaniasis in pregnancy and vertical transmission
    “Paromomycin crosses the placenta and can cause renal and auditory damage in the unborn child. Paromomycin is excreted in breast milk and adverse effects in ...
  44. [44]
    Cutaneous Leishmaniasis: Case Series on Pregnancy Outcome - NIH
    No teratogenic effects were reported. Furthermore, no vertical transmission was observed. Keywords: cutaneous leishmaniasis, paromomycin plus methylbenzethonium ...
  45. [45]
    Clinical Care of Leishmaniasis - CDC
    Mar 13, 2024 · Miltefosine is contraindicated in pregnant women. Women of reproductive potential should have a negative pregnancy test before starting therapy; ...
  46. [46]
    Paromomycin - Drugs and Lactation Database (LactMed®) - NCBI
    Sep 15, 2023 · No information is available on the clinical use of paromomycin during breastfeeding. Because paromomycin is poorly absorbed orally, it is not likely to reach ...
  47. [47]
    Paromomycin use while Breastfeeding - Drugs.com
    Dec 18, 2024 · No information is available on the clinical use of paromomycin during breastfeeding. Because paromomycin is poorly absorbed orally, it is not likely to reach ...
  48. [48]
    PAROMOMYCIN - ORAL (Humatin) side effects, medical uses, and ...
    SIDE EFFECTS: Nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and heartburn may occur. If any of these effects persist or worsen, tell your ...
  49. [49]
    Efficacy and safety of paromomycin for treating amebiasis in Japan
    Paromomycin was shown to be safe and well tolerated, as well as effective in a special subset of amebic colitis cases.Missing: guidelines | Show results with:guidelines
  50. [50]
  51. [51]
    Paromomycin (oral route) - Side effects & dosage - Mayo Clinic
    Nov 1, 2025 · Adults—4000 milligrams (mg) per day, divided in small doses, for 5 to 6 days. · Children—Use and dose must be determined by your doctor.
  52. [52]
    Dynamic changes of the luminal and mucosa-associated gut ... - NIH
    AB treatment affected gut microbiota of lumen and mucosa in a similar way, although paromomycin is known to be poorly absorbable after oral administration, with ...
  53. [53]
    Aminoglycosides - StatPearls - NCBI Bookshelf
    Jul 17, 2023 · In patients receiving aminoglycoside therapy, renal tubular toxicity decreased blood flow to the kidneys, and reduced GFR most commonly causes ...
  54. [54]
    Paromomycin - WikEM
    Jul 18, 2025 · Paromomycin binds to bacterial 30S ribosomal subunit, inhibiting protein synthesis; it suppresses urease producing bacteria, reducing ammonia ...Missing: Proteus Klebsiella
  55. [55]
    Paromomycin | Davis's Drug Guide - Nursing Central
    Adverse Reactions/Side Effects. GI: abdominal cramps, diarrhea, nausea, vomiting. Misc: hypersensitivity reactions. * CAPITALS indicate life-threatening.
  56. [56]
    Humatin - Drug Summary
    NOTE: Paromomycin is not FDA-approved for vaginal administration. Apply intravaginally only those paromomycin products labeled for intravaginal use.<|control11|><|separator|>
  57. [57]
    Lasix, Furoscix (furosemide) dosing, indications, interactions ...
    Increased risk of ototoxicity and nephrotoxicity. furosemide, paromomycin. Either increases toxicity of the other by Mechanism: pharmacodynamic synergism. ...
  58. [58]
    Paromomycin: Uses, Interactions, Mechanism of Action - DrugBank
    Paromomycin is an aminoglycoside antibiotic used in the treatment of acute and chronic intestinal amebiasis, and as an adjunct for the management of hepatic ...
  59. [59]
    Inactivation of digoxin by the gut flora: reversal by antibiotic therapy
    Oct 1, 1981 · We conclude that in some persons digoxin is inactivated by gastrointestinal bacteria. Changes in the enteric flora may markedly alter the state ...
  60. [60]
    Clinical Pharmacokinetics of Systemically Administered ... - PubMed
    Pentamidine is the only antileishmanial drug metabolised by cytochrome P450 enzymes. Paromomycin is excreted by the kidneys unchanged and is eliminated fastest ...
  61. [61]
    Pharmacists Resources: Vancomycin Drug Bug Cheat Sheet
    Aug 30, 2023 · Drug-Drug Interactions (DDA) Of Vancomycin · Aminoglycosides: The use of vancomycin with aminoglycosides can increase the risk of kidney damage.Missing: paromomycin | Show results with:paromomycin
  62. [62]
    Combined treatment of miltefosine and paromomycin delays the ...
    May 15, 2017 · Drug interaction studies using the fixed-ratio isobologram method revealed an indifferent interaction between paromomycin and miltefosine. In ...
  63. [63]
    Paromomycin | Johns Hopkins ABX Guide
    Sep 1, 2020 · Paromomycin ; FDA. Intestinal amebiasis; Hepatic coma ; NON-FDA APPROVED USES. Cryptosporidiosis; Dientamoeba fragilis.
  64. [64]
    Nephrotoxicity of antibiotics - PubMed
    Kidney / drug effects*; Neomycin / adverse effects; Paromomycin / adverse effects; Peritoneal Dialysis; Polymyxins / adverse effects; Renal Dialysis ...
  65. [65]
    Tobramycin - StatPearls - NCBI Bookshelf - NIH
    In addition, caution is necessary for elderly patients, those prone to dehydration, and those with preexisting conditions, including renal failure, ...
  66. [66]
    [PDF] Antibiotics, Gastrointestinal Therapeutic Class Review (TCR)
    Oct 4, 2022 · Oral vancomycin remains the drug of choice for a fulminant episode of C. difficile infection (strong recommendation). For recurrent C. difficile ...
  67. [67]
    Paromomycin binding induces a local conformational change in the ...
    Mar 27, 1998 · Aminoglycoside antibiotics that bind to ribosomal RNA in the aminoacyl-tRNA site (A-site) cause misreading of the genetic code and inhibit translocation.
  68. [68]
    Mechanisms of action of aminoglycoside antibiotics in eucaryotic ...
    We conclude that the primary inhibitory action of paromomycin and gentamicin G418 was at (i) an early stage of elongation after initiation, (ii) the initiation ...
  69. [69]
    Differential Effects of Paromomycin on Ribosomes of Leishmania ...
    In the present article, we show that paromomycin causes a strong inhibition of polyphenylalanine synthesis directed by poly(U) in a cell-free system prepared ...
  70. [70]
    Paromomycin inhibits Cryptosporidium infection of a ... - PubMed - NIH
    Paromomycin concentrations ranging from 50 to 5000 micrograms/ml inhibited infection at 24 h in a dose-dependent fashion. Concentrations greater than 1000 ...
  71. [71]
  72. [72]
    Differential effects of paromomycin on ribosomes of Leishmania ...
    Oct 18, 2010 · In order to understand the mode of action of this antibiotic at the molecular level, we have investigated the effects of parom …
  73. [73]
    Investigational Drugs for Visceral Leishmaniasis - PMC
    ... paromomycin (PM); or 10 days each of miltefosine and PM) are the ... donovani promastigote - 14.5 μg/ml Amastigote - 11.2 μg/ml. 20μg/kg and 40μg ...
  74. [74]
    Evaluation of a Possible Synergistic Effect of Meglumine ...
    Conclusion. Combination of Glucantime with paromomycin, miltefosine or allopurinol showed a synergistic effect on the clinical isolate of L. tropica in vitro. ...
  75. [75]
    Paromomycin and Geneticin Inhibit Intracellular Cryptosporidium ...
    Paromomycin inhibits both bacterial and eukaryotic ribosomal protein synthesis, though eukaryotic organisms are 10 to 15 times less sensitive than prokaryotic ...
  76. [76]
    Investigation of in vitro absorption, distribution, metabolism, and ...
    The objective of this study is to investigate in vitro Caco2 permeability, metabolism and in vivo pharmacokinetic (PK) properties of paromomycin to develop ...
  77. [77]
    Clinical Pharmacokinetics of Systemically Administered ...
    Pentamidine is the only antileishmanial drug metabolised by cytochrome P450 enzymes. Paromomycin is excreted by the kidneys unchanged and is eliminated fastest ...
  78. [78]
    Pharmacokinetics and Absorption of Paromomycin and Gentamicin ...
    Paromomycin concentrations in plasma after 20 days of application were 5 to 9% of those after intramuscular administration of 15 mg/kg of body weight/day to ...Missing: ointment | Show results with:ointment
  79. [79]
    Geographical Variability in Paromomycin Pharmacokinetics Does ...
    Jun 9, 2021 · Intramuscular paromomycin monotherapy to treat visceral leishmaniasis (VL) has been shown to be effective for Indian patients, while a similar regimen resulted ...
  80. [80]
    Paromomycin - ScienceDirect.com
    It is out of use as an antibiotic but was licensed in 2007 in India as an effective, well tolerated and affordable treatment for visceral leishmaniasis (VL) at ...Review · Summary · Pharmacokinetics And...
  81. [81]
    The Blood–Brain Barrier and Pharmacokinetic/Pharmacodynamic ...
    Dec 19, 2022 · Penetration of aminoglycosides in the presence of significant meningeal inflammation remains poor because brain capillaries lack the ...
  82. [82]
    Geographical Variability in Paromomycin Pharmacokinetics Does ...
    Jun 9, 2021 · Paromomycin is poorly absorbed after oral administration [9, 10], however after intramuscular administration, absorption is fast, with peak ...
  83. [83]
    The kinetics of aminosidine in renal patients with different degrees of ...
    In normal subjects the plasma half-life is 2.47 hr; in patients with creatinine clearance (Ccr) of 30-60 ml/min, its 6.7 hrs.; in patients with Ccr of 10-30 ml ...Missing: anuria | Show results with:anuria
  84. [84]
    Recommended Dosing Adjustments of Drugs Used to Prevent and ...
    Apr 23, 2025 · This table provides dosing guidelines for drugs used to treat or prevent opportunistic infections in adults and adolescents with HIV and ...
  85. [85]
    US2916485A - Antibiotic and methods for obtaining same
    The production of paromomycin in accordance with the invention is carried out by inoculating a sterile aqueous nutrient medium with Streptomyces rimosus forma ...
  86. [86]
    paromomycin | Ligand page
    Synonyms: aminosidine | catenulin | Humatin® | monomycin A ; approved drug (FDA (1969)) ; Compound class: Natural product ; Comment: Paromomycin belongs to the ...
  87. [87]
    PAROMOMYCIN. IV. STRUCTURAL STUDIES - ACS Publications
    PAROMOMYCIN. IV. STRUCTURAL STUDIES. Click to copy article linkArticle link copied! Theodore H. Haskell · James C. French · Quentin R. Bartz. ACS Legacy Archive.
  88. [88]
    Paromomycin - Wikipedia
    Paromomycin is an antimicrobial used to treat a number of parasitic infections including amebiasis, giardiasis, leishmaniasis, and tapeworm infection.Missing: FDA | Show results with:FDA
  89. [89]
    Randomised controlled trial of aminosidine (paromomycin) v sodium ...
    Objectives: To assess the efficacy and tolerability of aminosidine compared with sodium stibogluconate for treating visceral leishmaniasis.
  90. [90]
    Phase 4 Pharmacovigilance Trial of Paromomycin Injection for the ...
    Sep 29, 2011 · Paromomycin was shown to be safe and effective for treatment of VL in a phase 3 clinical trial in India, with a final cure rate of 94.6% [11].
  91. [91]
    Topical paromomycin for New World cutaneous leishmaniasis - PMC
    May 2, 2019 · Paromomycin-based topical treatments were shown to be effective in curing cutaneous leishmaniasis (CL) lesions caused by Leishmania major in ...
  92. [92]
    Drugs for Neglected Diseases Initiative (DNDi): matching needs and ...
    Unfortunately, people suffering from these diseases do not constitute a market lucrative enough to attract investment in research and development for new drugs.
  93. [93]
    Miltefosine + Paromomycin combination (Africa) - DNDi
    The project objective is to compare the efficacy and safety of two combination regimens of miltefosine and paromomycin with the current standard treatment.Missing: challenges | Show results with:challenges
  94. [94]
    Paromomycin - eEML - Electronic Essential Medicines List
    The updated 2025 WHO Model Lists of Essential Medicine were released on 5 September 2025. ... Paromomycin is an antimicrobial medicine used in the ...
  95. [95]
    [PDF] Guidelines for the Prevention and Treatment of Opportunistic ...
    Sep 9, 2025 · Panel on Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents. With HIV. Guidelines for the ...