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Maprotiline

Maprotiline is a tetracyclic antidepressant medication primarily used to treat major depressive disorder, depressive neurosis (dysthymic disorder), and anxiety associated with depression.^[1]^[2] Structurally distinct from tricyclic antidepressants due to its four-ring configuration, maprotiline is available as hydrochloride salt tablets in strengths of 25 mg, 50 mg, and 75 mg, with a typical initial dosage of 75 mg per day for outpatients, adjustable up to 225 mg based on response.^[2]^[1] The drug exerts its therapeutic effects by selectively inhibiting the reuptake of norepinephrine at central adrenergic synapses, thereby enhancing noradrenergic neurotransmission to alleviate depressive symptoms, while exhibiting minimal impact on serotonin reuptake.^[2]^[1] It demonstrates weak anticholinergic, antihistaminic, and alpha-adrenergic blocking activities, contributing to its sedative properties but also potential side effects such as drowsiness and dry mouth.^[2] Pharmacokinetically, maprotiline reaches peak plasma concentrations approximately 12 hours after administration and has an average elimination half-life of 51 hours (ranging from 27 to 58 hours), allowing for once- or twice-daily dosing.^[1] Approved by the U.S. Food and Drug Administration in 1980, maprotiline was discontinued in the United States in 2021 but remains available in other countries.^[3] It carries significant safety warnings, including an increased risk of suicidal ideation and behavior in children, adolescents, and young adults under 25, as well as potential for seizures (incidence <0.1%) and cardiovascular effects in susceptible patients.^[2]^[1] Contraindications include hypersensitivity to the drug, concurrent use of monoamine oxidase inhibitors, and acute recovery phases of myocardial infarction; it is not recommended for children under 18.^[1] Common adverse effects encompass nausea, dizziness, and weight gain, with overdose risks involving convulsions, hypotension, and coma, underscoring the need for close monitoring during therapy.^[4]^[2]

Medical uses

Primary indications

Maprotiline is approved for the treatment of depressive illness, specifically depressive neurosis (dysthymic disorder) and the depressed phase of manic-depressive illness (major depressive disorder). It is also indicated for the relief of anxiety symptoms associated with depression, particularly in cases involving agitation.^[1] Clinical trials have demonstrated that maprotiline exhibits efficacy comparable to tricyclic antidepressants (TCAs) such as imipramine in treating moderate to severe depression, with both agents producing significant reductions in depressive symptoms on scales like the Hamilton Depression Rating Scale. In a multicenter double-blind study of 341 patients with severe depression, maprotiline and imipramine showed equivalent overall response rates, with no statistically significant differences in symptom improvement after four weeks of treatment. Response rates for maprotiline in such trials align with general antidepressant outcomes, typically ranging from 50% to 60% in moderate to severe cases.^[5]^[6] Due to its sedative properties, maprotiline is particularly suitable for patients with melancholic features of depression or comorbid insomnia, as it can help alleviate sleep disturbances and psychomotor agitation without substantially disrupting REM sleep phases compared to some TCAs. This profile makes it a preferred option in profiles involving prominent anxiety or agitation alongside core depressive symptoms.^[7]^[8]

Dosage and administration

Maprotiline is typically initiated at a dose of 75 mg per day orally for outpatients with mild to moderate depression, while hospitalized patients with moderate to severe depression may start at 100 to 150 mg per day.^[1] For elderly patients, a lower initial dose of 25 to 50 mg per day is recommended to minimize risks associated with reduced clearance.^[9]^[10] Titration should occur gradually after an initial 2-week period at the starting dose, with increases of 25 mg every 1 to 2 weeks based on clinical response and tolerability, up to a maintenance dose of 75 to 150 mg per day.^[1] The maximum daily dose is 225 mg, though doses exceeding 200 mg are associated with an increased risk of seizures, necessitating careful monitoring during escalation.^[1]^[9] The medication is administered orally as a single daily dose, preferably at bedtime to capitalize on its sedative properties, or in divided doses throughout the day if needed for tolerability.^[11] It may be taken with or without food, as absorption is not significantly affected by meals.^[4] Therapeutic effects may begin within 3 to 7 days, but full response often requires 2 to 3 weeks, with initial efficacy assessments typically conducted after 4 to 6 weeks of treatment.^[1] Patients should undergo regular clinical monitoring for efficacy and tolerability, including assessment of depressive symptoms and potential clinical worsening, particularly in the first few weeks or during dose adjustments.^[1] In at-risk individuals, such as those with cardiovascular disease, baseline and periodic ECG monitoring for QT interval prolongation is advised due to the drug's potential to delay cardiac repolarization.^[12]

Available forms

Maprotiline is formulated as oral tablets in the hydrochloride salt form, which provides enhanced chemical stability for pharmaceutical use. The available tablet strengths are 25 mg, 50 mg, and 75 mg of maprotiline hydrochloride.^[1] Administration is exclusively oral, with no approved injectable, topical, or other routes of delivery available.^[11] Tablets should be stored at controlled room temperature between 20°C and 25°C (68°F to 77°F), protected from light, and dispensed in a tight, light-resistant container to maintain efficacy and prevent degradation.^[1] Maprotiline tablets are no longer available in the United States, having been discontinued in June 2021 by the sole supplier, Mylan. Generic versions remain available in some international markets.^[13]

Contraindications and precautions

Absolute contraindications

Maprotiline is contraindicated in patients with known hypersensitivity to the drug itself.^[1] This includes individuals with a history of allergic reactions to maprotiline or its components.^[7] The drug is absolutely prohibited in those with known or suspected seizure disorders, as maprotiline can lower the seizure threshold and precipitate convulsions.^[1]^[7] Similarly, it is contraindicated during the acute recovery phase following myocardial infarction due to the risk of exacerbating cardiac instability.^[1]^[7] Concurrent administration with monoamine oxidase inhibitors (MAOIs) is strictly forbidden, owing to the potential for severe interactions including hypertensive crisis; at least 14 days should elapse after discontinuing an MAOI before starting maprotiline.^[1]^[7] Maprotiline must not be used in patients with uncontrolled narrow-angle glaucoma, as its anticholinergic effects can increase intraocular pressure and worsen the condition.^[7] It is also contraindicated in cases of acute congestive heart failure or severe hepatic or renal impairment, where the drug's risks outweigh any potential benefits.^[7] Contraindications may vary by jurisdiction; for example, in Canada, it is contraindicated in narrow-angle glaucoma and acute congestive heart failure, while U.S. labeling advises caution.

Use in special populations

Maprotiline is classified as FDA Pregnancy Category B, indicating no evidence of risk to the fetus in animal reproduction studies, but there are no adequate and well-controlled studies in pregnant women.^[1] Due to limited human data on its safety during pregnancy, it should be used only if the potential benefit justifies the potential risk to the fetus.^[14] Maprotiline is excreted into breast milk, and its use during lactation is not recommended unless the benefits to the mother outweigh the risks to the infant.^[15] Infants should be monitored for possible adverse effects such as sedation or irritability if exposure occurs.^[16] Maprotiline is not approved for use in pediatric patients under 18 years of age, as safety and efficacy have not been established in this population.^[4] It carries an increased risk of suicidal ideation and behavior in children, adolescents, and young adults, necessitating close monitoring; additionally, maprotiline is associated with a higher incidence of seizures compared to tricyclic antidepressants, particularly in vulnerable groups.^[1]^[17] Limited data are available, but use is generally avoided.^[16] In elderly patients, maprotiline dosing should begin at a lower initial dose of 25 mg daily, with maintenance doses typically ranging from 50 to 75 mg daily, due to increased sensitivity to anticholinergic effects, sedation, and orthostatic hypotension, which heighten the risk of falls and confusion.^[9]^[11] For patients with hepatic or renal impairment, maprotiline is contraindicated in severe cases; cautious use with potential dose reductions is required in milder impairment to prevent drug accumulation, as its metabolism and elimination may be altered; close monitoring of plasma levels and clinical response is advised.^[18]^[19]^[20] In patients with bipolar disorder, maprotiline monotherapy may precipitate a switch to mania or hypomania, so it should be used only in conjunction with a mood stabilizer and under close supervision.^[1]^[4]

Adverse effects

Common side effects

Maprotiline commonly causes mild to moderate adverse reactions, similar to those of tricyclic antidepressants, primarily stemming from its antihistaminic and anticholinergic properties. In clinical trials, the most frequent side effects reported in more than 10% of patients include sedation and dry mouth. These effects are generally dose-related and may decrease over time with continued use.^[1] Sedation and drowsiness occur in approximately 16% of patients, largely due to maprotiline's antagonism of histamine H1 receptors. This side effect is particularly prominent during the initial weeks of therapy but often attenuates after 1 to 2 weeks as tolerance develops; patients are advised to avoid operating machinery until its impact is clear.^[1]^[21]^[22] Dry mouth, resulting from anticholinergic activity, affects about 22% of users and can lead to discomfort or increased risk of dental issues if unmanaged. Strategies such as increased fluid intake, sugar-free lozenges, and good oral hygiene are recommended to alleviate this effect.^[1]^[21] Constipation is reported in 6% to 10% of patients, also attributable to anticholinergic blockade, and is more common in elderly individuals. It can typically be prevented or treated through dietary measures like higher fiber consumption and adequate hydration.^[1]^[23] Weight gain is a notable concern, with clinically relevant increases occurring in up to 48% of patients and an average gain of 1.8 kg within the first two months, often linked to enhanced appetite. Monitoring body weight and dietary habits is suggested during treatment.^[24] Dizziness, including orthostatic components, arises in around 8% of cases, particularly early in treatment, and is related to mild alpha-1 adrenergic antagonism; rising slowly from sitting or lying positions can help mitigate this risk.^[1]^[22] Sexual dysfunction, such as decreased libido or erectile difficulties, is less frequent with maprotiline compared to other antidepressants but still affects 1% to 10% of users.^[23]

Serious side effects

Maprotiline, a tetracyclic antidepressant, is associated with several serious side effects that require immediate medical attention, including seizures, cardiac arrhythmias, serotonin syndrome, blood dyscrasias, hepatic toxicity, and suicidal ideation.^[1] Seizures represent a significant risk with maprotiline use, particularly in a dose-dependent manner, with incidence rates estimated at 0.1% to 0.4% in clinical trials at therapeutic doses below 200 mg/day, rising to approximately 1% or higher at doses exceeding 200 mg/day based on post-marketing data.^[25]^[26] The risk is substantially elevated in patients with a history of epilepsy or other seizure disorders, and factors such as rapid dose escalation or concomitant use of phenothiazines may further increase susceptibility; therapy should begin at low doses with gradual titration to minimize this hazard.^[1]^[4] Cardiac arrhythmias, including QT interval prolongation and tachycardia, have been reported with maprotiline, posing a heightened risk in patients with preexisting cardiovascular conditions such as conduction defects or a history of myocardial infarction.^[1]^[27] Electrocardiographic monitoring is recommended for at-risk individuals, as these effects can lead to serious events like torsades de pointes ventricular tachycardia.^[12] Serotonin syndrome may occur when maprotiline is combined with other serotonergic agents, manifesting as hyperthermia, muscle rigidity, autonomic instability, and altered mental status, which can be life-threatening if not promptly addressed.^[28] Blood dyscrasias, such as agranulocytosis and thrombocytopenia, are rare but severe complications of maprotiline therapy, with bone marrow depression reported in isolated cases.^[1] Patients should be advised to monitor for signs like fever or sore throat and undergo complete blood count testing if symptoms arise, with immediate discontinuation if neutropenia is confirmed.^[4] Hepatic toxicity is uncommon, with elevated liver enzymes occurring in less than 1% of patients, though rare instances of jaundice or altered liver function necessitate prompt evaluation and potential withdrawal of the drug.^[1]^[29] Suicidal ideation carries a black box warning for maprotiline, as with all antidepressants, due to an increased risk in children, adolescents, and young adults (up to age 24), with approximately 5 additional cases per 1,000 patients treated compared to placebo, particularly during the initial weeks of therapy or dose adjustments.^[1] Close monitoring by patients, families, and caregivers is essential, especially early in treatment.^[4] Certain drug interactions, such as with serotonergic medications, can exacerbate these serious effects like serotonin syndrome or seizures.^[28]

Withdrawal effects

Abrupt discontinuation of maprotiline can lead to a discontinuation syndrome, characterized by symptoms that typically emerge within 1 to 3 days of stopping the medication and resolve within 1 to 2 weeks.^[30]^[31] The incidence of discontinuation syndrome with maprotiline is not specifically quantified in primary sources but is estimated to be similar to that of other antidepressants, around 20% in patients who have used the drug for at least 6 weeks. Recent meta-analyses (as of 2024) estimate discontinuation symptoms in 42-56% of antidepressant users overall, though specific data for maprotiline remains limited.^[30]^[32] Common symptoms include flu-like malaise, insomnia, anxiety, nausea, headache, and gastrointestinal disturbances such as vomiting, stomach pain, and diarrhea.^[30]^[31] These are often accompanied by cholinergic rebound effects due to the drug's anticholinergic properties, manifesting as increased sweating, diarrhea, and abdominal cramping, though these are less pronounced in maprotiline compared to typical tricyclic antidepressants (TCAs) owing to its relatively weaker muscarinic receptor blockade.^[33]^[22] Severity is influenced by factors such as rapid discontinuation or prolonged use exceeding 6 months, which can exacerbate the intensity of symptoms.^[30] Management primarily involves gradual dose reduction to minimize risks, typically tapering over 2 to 4 weeks by decreasing the dose in increments of 25 mg every 3 to 7 days, depending on patient tolerance.^[25]^[30] For persistent symptoms, symptomatic relief may include short-term use of benzodiazepines to address anxiety and insomnia, while anticholinergic agents can be considered for pronounced cholinergic rebound effects.^[30] If severe symptoms occur, resuming the medication at a lower dose and restarting the taper is recommended.^[25]

Drug interactions

Pharmacokinetic interactions

Maprotiline is primarily metabolized by the cytochrome P450 enzyme CYP2D6, with minor contributions from CYP1A2, making it susceptible to pharmacokinetic interactions involving these pathways. Inhibitors of CYP2D6, such as fluoxetine, can significantly elevate maprotiline plasma concentrations by slowing its metabolism; for instance, co-administration has been used therapeutically in ultra-rapid metabolizers to achieve adequate levels, but routine use requires monitoring for toxicity due to increased exposure.^[34]^[35] Similarly, cimetidine, a non-specific inhibitor of hepatic enzymes including CYP2D6, reduces maprotiline clearance, leading to higher serum levels and necessitating dose adjustments or close clinical observation to avoid adverse effects.^[36]^[19] Enzyme inducers like carbamazepine and phenytoin accelerate maprotiline metabolism, potentially decreasing its efficacy by lowering plasma concentrations. Carbamazepine, a potent inducer of CYP3A4 and other enzymes, has been shown to increase maprotiline clearance, often requiring higher doses to maintain therapeutic levels.^[22] Phenytoin similarly enhances metabolism through induction of hepatic enzymes.^[22] Maprotiline exhibits high protein binding (approximately 88%), primarily to alpha-1-acid glycoprotein, which can lead to displacement interactions with other highly bound drugs, though clinically significant cases are rare. Concomitant use with warfarin, another highly protein-bound agent, may increase free fractions of either drug, warranting monitoring of international normalized ratio (INR) to prevent bleeding risks, despite limited direct evidence of displacement for maprotiline specifically.^[22]^[18] Excretion is predominantly hepatic, with only about 60% of metabolites eliminated renally, resulting in minimal pharmacokinetic interactions via renal pathways. However, caution is advised with lithium, as maprotiline may reduce lithium excretion, leading to elevated lithium levels and additive risks in patients with compromised renal function, though this primarily impacts lithium pharmacokinetics rather than maprotiline's.^[22]^[22]

Pharmacodynamic interactions

Maprotiline, a tetracyclic antidepressant primarily acting as a norepinephrine reuptake inhibitor, can engage in pharmacodynamic interactions with other agents that modulate neurotransmitter systems or central nervous system activity, leading to enhanced or opposed physiological effects.^[22] Concomitant use with monoamine oxidase inhibitors (MAOIs) is contraindicated due to the risk of severe hypertensive crisis from excessive norepinephrine accumulation or serotonin syndrome from combined serotonergic effects, despite maprotiline's weaker serotonin reuptake inhibition; a minimum washout period of 14 days is required after discontinuing MAOIs before initiating maprotiline.^[1]^[22] Interactions with other antidepressants often involve additive effects on sedation or seizure threshold. For instance, coadministration with tricyclic antidepressants (TCAs) or mirtazapine can potentiate central nervous system depression and sedation through shared antihistaminic and noradrenergic properties, necessitating dosage adjustments and monitoring for excessive drowsiness.^[22] Similarly, combining maprotiline with bupropion increases the risk of seizures, as both agents lower the seizure threshold via noradrenergic enhancement and other mechanisms.^[37] Maprotiline enhances the sedative effects of central nervous system (CNS) depressants, including alcohol, benzodiazepines, and opioids, resulting in profound impairment of psychomotor function; patients are advised to avoid activities requiring alertness, such as driving, during concurrent use.^[11]^[22] When used with anticholinergic agents, such as atropine-like drugs, maprotiline exacerbates anticholinergic side effects like dry mouth and constipation due to its own moderate anticholinergic activity at muscarinic receptors, requiring close supervision and careful dosing.^[1] Sympathomimetic agents like ephedrine can lead to potentiated hypertensive effects with maprotiline, owing to the drug's inhibition of norepinephrine reuptake, which amplifies the catecholaminergic response; blood pressure monitoring is essential in such combinations.^[22]^[1]

Pharmacology

Pharmacodynamics

Maprotiline is classified as a tetracyclic antidepressant (TeCA), structurally bridging tricyclic antidepressants (TCAs) and atypical antidepressants due to its four-ring configuration.^[22] Its primary mechanism of action involves potent and selective inhibition of norepinephrine reuptake at the presynaptic neuron, with a binding affinity (Ki) of 11 nM at the norepinephrine transporter (NET).^[38] This selectivity is evident in its weak inhibition of serotonin reuptake (Ki = 5.8 μM at the serotonin transporter, SERT) and negligible effects on dopamine reuptake (Ki = 1 μM at the dopamine transporter, DAT).^[38] In addition to its reuptake inhibition, maprotiline binds to several neurotransmitter receptors, contributing to its overall pharmacological profile. It acts as a strong antagonist at histamine H1 receptors (Ki ≈ 0.8 nM), which underlies its sedative properties.^[39]^[40] Moderate antagonism at alpha-1 adrenergic receptors (Ki ≈ 90 nM) can lead to orthostatic hypotension as a downstream effect.^[38] Maprotiline also shows weak antagonism at muscarinic acetylcholine receptors (Ki ≈ 570 nM), resulting in lower anticholinergic activity compared to TCAs such as amitriptyline (Ki ≈ 20 nM).^[38] By elevating synaptic norepinephrine concentrations through NET inhibition, maprotiline exerts its core antidepressant effects, promoting mood elevation in conditions like major depressive disorder.^[22] The H1 receptor blockade provides ancillary benefits, including anxiety relief and sleep promotion via sedation.^[41] Unlike typical TCAs, maprotiline demonstrates reduced sodium channel blockade, contributing to a relatively lower risk of cardiotoxicity in therapeutic doses.^[42]

Pharmacokinetics

Maprotiline is slowly but completely absorbed from the gastrointestinal tract after oral administration, with an absolute bioavailability of 66-70%. Peak plasma concentrations are reached approximately 12 hours post-dose, owing to delayed absorption influenced by its anticholinergic effects and enterohepatic recirculation.^[43]^[1]^[18] The drug exhibits extensive distribution throughout the body, with a volume of distribution estimated at 23-27 L/kg, reflecting its lipophilic nature and penetration into tissues such as the lungs, liver, brain, and kidneys. Maprotiline is highly bound to plasma proteins (approximately 88%), primarily to alpha-1-acid glycoprotein, though lower concentrations are noted in organs like the adrenal glands and heart. It readily crosses the blood-brain barrier, facilitating its antidepressant effects in the central nervous system, and is distributed into breast milk at concentrations similar to those in maternal plasma.^[19]^[22]^[44] Maprotiline undergoes hepatic metabolism primarily via the cytochrome P450 2D6 (CYP2D6) enzyme, involving N-demethylation to form desmethylmaprotiline, an active metabolite, along with other pathways such as deamination, hydroxylation, and formation of methoxy derivatives. This metabolism is genetically polymorphic; poor CYP2D6 metabolizers exhibit significantly higher plasma concentrations (up to 3.5-fold increased area under the curve) and prolonged effects compared to extensive metabolizers.^[22]^[45]^[46] Elimination of maprotiline is characterized by a half-life of 27-58 hours (mean 51 hours), contributing to its accumulation with repeated dosing. The drug and its metabolites are excreted predominantly via the urine (about 60%, mostly as conjugates) and feces (about 30%), with only 2-4% of the unchanged parent compound recovered in urine. Steady-state plasma concentrations are generally achieved within 7-14 days of consistent dosing, with levels in the range of 100-400 ng/mL associated with therapeutic efficacy at typical doses of 75-225 mg daily.^[1]^[7]^[47]^[48]

Chemistry

Chemical structure and classification

Maprotiline features a tetracyclic ring system consisting of two benzene rings fused to a central seven-membered azepine ring bridged by an ethano group, forming a rigid dibenzobicyclooctadiene nucleus, with a propyl side chain attached at the bridgehead position bearing a terminal N-methylamino group.^[22] This structure distinguishes it from tricyclic antidepressants, which lack the bridging ethano moiety across the central ring, resulting in a non-planar, bridged tetracyclic core that imparts unique steric properties.^[2] The molecular formula of maprotiline is C₂₀H₂₃N, with a molecular weight of 277.4 g/mol for the free base and 313.9 g/mol for the hydrochloride salt commonly used in formulations.^[2]^[8] The IUPAC name for maprotiline is methyl(3-{tetracyclo[6.6.2.0^2,7.0^9,14]hexadeca-2,4,6,9,11,13-hexaen-1-yl}propyl)amine.^[22] As a secondary amine due to the single methyl substitution on the nitrogen, maprotiline belongs to the class of tetracyclic antidepressants (TeCAs), a subclass of second-generation antidepressants that includes structurally related compounds like amoxapine, though maprotiline's azepine-based bridged system provides a distinct pharmacophore compared to amoxapine's oxazepine ring.^[22] Maprotiline is achiral, possessing no stereocenters or optical isomers, owing to the symmetric bridged tetracyclic framework that eliminates asymmetry in the core structure.^[2]

Physicochemical properties

Maprotiline is typically encountered as its hydrochloride salt in pharmaceutical formulations, presenting as a fine, white to off-white, practically odorless crystalline powder.^[1] The free base form appears as a solid, often described similarly in chemical databases.^[2] Regarding solubility, the hydrochloride salt is freely soluble in methanol and chloroform, slightly soluble in water, and practically insoluble in isooctane.^[1] This represents an improvement over the free base, which exhibits very low aqueous solubility of approximately 0.83 mg/L at 22.5°C and 38.6 µg/mL at pH 7.4, though it is also freely soluble in organic solvents like chloroform and methanol.^[49]^[2] The hydrochloride form thus enhances aqueous solubility by roughly an order of magnitude, facilitating formulation for oral administration.^[1] Key ionization and lipophilicity parameters include a pKa of 10.5 for the secondary amine group, indicating basic character, and a logP value of approximately 5.1, reflecting high lipophilicity that supports central nervous system penetration.^[49]^[22] The melting point of the free base is 92–94°C, while the hydrochloride salt melts at 230–232°C.^[49]^[50] Maprotiline hydrochloride demonstrates sensitivity to light, with instability observed under intensified ICH photostability conditions (400 W/m² and 2.4 × 10⁶ lx h).^[51] It is also susceptible to oxidation, showing 17.16% degradation upon exposure to 3% H₂O₂ at room temperature for 4 hours.^[52] The compound remains relatively stable under neutral conditions but degrades in strong acidic (25.65% in 0.1 M HCl at 80°C for 4 hours) and basic (12.24% in 0.1 M NaOH at 80°C for 4 hours) environments, influencing storage and formulation strategies to maintain stability at neutral pH.^[52] Thermal stability is high, with only 1.31% degradation at 105°C for 1 hour.^[52] These properties collectively affect bioavailability, as the lipophilic nature and salt form optimization aid absorption in the gastrointestinal tract.^[22]

History and availability

Development and approval history

Maprotiline was developed by Ciba (later Ciba-Geigy and now part of Novartis) in the 1960s as a potential alternative to tricyclic antidepressants, aiming to offer similar efficacy with possibly improved tolerability. The compound, chemically distinct due to its tetracyclic structure, was patented in the United States in 1968 under US Patent 3,399,201 assigned to Ciba. It was first described in the scientific literature in 1969, highlighting its potential as a norepinephrine reuptake inhibitor.^[53] Clinical development progressed through the 1970s, with phase III trials demonstrating efficacy in treating major depressive disorder comparable to established tricyclic agents. Maprotiline received approval in Switzerland in 1972 and was introduced across Europe in 1974 as Ludiomil, marking it as the first tetracyclic antidepressant (TeCA) to reach the market. In the United States, the FDA approved it in December 1980 for the treatment of depression under the brand name Ludiomil, based on data from controlled trials showing antidepressant effects at doses of 75–150 mg daily.^[1] Post-marketing surveillance in the 1980s identified an elevated risk of seizures associated with maprotiline, particularly at higher doses exceeding 200 mg daily, prompting regulatory updates to limit maximum dosing to 150–225 mg/day depending on patient factors and to contraindicate use in those with seizure disorders.^[1] As of 2025, preliminary research has investigated off-label applications, including amelioration of high glucose-induced renal glomerular endothelial dysfunction in diabetic nephropathy models and suppression of proliferation in T-cell lymphoma cells via AKT/mTOR pathway inhibition, though no new approvals have resulted from these studies.^[54]^[55] In the United States, maprotiline was withdrawn from the market in June 2021 due to manufacturing issues by its sole supplier, Mylan Pharmaceuticals.^[13]

Brand names and legal status

Maprotiline is the international nonproprietary name (INN) for the drug, with the generic form commonly available as maprotiline hydrochloride.^[2] The original brand name is Ludiomil, which has been discontinued in many markets, including the United States and Canada; other international brand names include Maprostad and Mirpan in Germany, Melodil in Israel, Psymion in Germany, and Retinyl in Greece.^[56]^[19]^[57] Maprotiline is classified as a prescription-only medication (Rx-only) worldwide and is not a controlled substance under the United States Drug Enforcement Administration (DEA) schedules.^[22]^[58] In the United Kingdom, maprotiline was discontinued in July 2006. In the United States, the branded version and generic tablets were discontinued by the sole manufacturer, Mylan, in June 2021, leading to limited availability and ongoing shortages. In Canada, manufacturing for sale ceased, and it is no longer available under any brand names. Generics remain accessible in the European Union through various marketing authorizations, though in September 2025, Ludiomil (maprotiline hydrochloride) tablets (25 mg, 50 mg, and 75 mg) were voluntarily recalled in Portugal by the supplier due to an impurity detected above acceptable limits; affected batches should not be used, and patients are advised to consult healthcare providers for alternatives.^[13]^[59]^[60]^[61] Post-2021 shortages have been reported in affected regions, with healthcare providers recommending alternatives such as other tetracyclic or tricyclic antidepressants. As of November 2025, maprotiline is used in a limited number of countries, primarily in Europe (excluding discontinued or recalled markets like Portugal), reflecting its lower market share amid the prevalence of newer antidepressants like SSRIs.^[62]^[63]^[64]

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Q-T prolongation and torsades de pointes ventricular tachycardia ...
Mar 1, 1983 · This report describes a patient in whom maprotiline treatment caused QT prolongation and life-threatening torsades de pointes ventricular tachycardia (VT).
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Serotonin Syndrome Due to Association of Venlafaxine, Maprotiline ...
Serotonin Syndrome Due to Association of Venlafaxine, Maprotiline and Reboxetine. Eur Psychiatry. 2004 Nov;19(7):456-7. doi: 10.1016/j.eurpsy.2004.06.012.
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Antidepressant-Induced Liver Injury: A Review for Clinicians
Antidepressant drugs can cause drug-induced liver injury (DILI). The authors review clinical data relevant to antidepressant-induced liver injury.
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Antidepressant Discontinuation Syndrome - AAFP
Aug 1, 2006 · These medications include selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), and ...Missing: maprotiline reliable sources
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Tetracyclic Antidepressants - American Addiction Centers
Aug 23, 2024 · Tetracyclics are a subclass of antidepressants that include mirtazapine (Remeron) and maprotiline (Ludiomil).Missing: reliable | Show results with:reliable
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Tetracyclic Antidepressant - an overview | ScienceDirect Topics
The main group of symptoms is related to cholinergic withdrawal ... Amitriptyline and maprotiline were the agents most commonly associated with this ...
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Non-response to maprotiline caused by ultra-rapid metabolism that ...
The therapeutic regiment was changed to co-administration of 200 mg maprotiline and 20 mg fluoxetine once per day in order to inhibit metabolism via CYP2D6.
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Pharmacogenomics of Antidepressants
Maprotiline is a major substrate of CYP2D6, a minor substrate of CYP1A2, CYP2C19, and CYP3A4 enzymes, inhibits MAOB and SLC6A2, and is transported by ABCB1 and ...
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cimetidine - Drug Summary
In a drug interaction study, cimetidine increased the AUC of cisapride by 45%. ... Maprotiline: (Moderate) Cimetidine can inhibit the systemic clearance of ...
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Maprotiline metabolism appears to co‐segregate with the ...
Maprotiline metabolism appears to co-segregate with the genetically- determined CYP2D6 polymorphic hydroxylation of debrisoquine. ... The pharmacokinetic ...
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Maprotiline - an overview | ScienceDirect Topics
Dosages of maprotiline were 75–300 mg/day, and each patient had undergone a dosage increase in the week before the seizure. A report based on experience in one ...
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Do Psychotropic Medications Cause Seizures? - NEJM Journal Watch
Oct 5, 2007 · Bupropion, maprotiline, amoxapine, clomipramine, and clozapine are associated with a dose-dependent lowering of the seizure threshold at clinically relevant ...
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Histamine H1 receptors in human brain labelled with [3H]doxepin
Tetracyclic antidepressants, mianserin and maprotiline, were very potent, with KDs of 3.6 +/- 0.7 X 10(-10) M and 7.9 +/- 0.5 X 10(-10) M, respectively.
[38]
Association of sleep among 30 antidepressants: a population-wide ...
Maprotiline, a tetracyclic antidepressant, was ranked third among the thirty antidepressants and binds to the H1 receptor (Ki = 1.7 nM) and NET (Ki = 11.1 nM) ...
[39]
Antagonism by Antidepressants of Muscarinic ... - PubMed
4 There was a significant correlation between the data for human and murine receptors and for eight compounds (imipramine, desipramine, maprotiline ... KD values ...Missing: 1984 H1 alpha
[40]
an antidepressant with an unusual pharmacological profile - PubMed
Maprotiline, which differs from other typical tricyclic antidepressants for its tetracyclic structure, is a highly selective inhibitor of norepinephrine ...
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Norepinephrine transporter inhibitors and their therapeutic potential
Maprotiline (14), which differs from other typical tricyclic antidepressants by its tetracyclic structure, is a highly selective inhibitor of NE reuptake in the ...
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Plasma protein binding of maprotiline in geriatric patients - PubMed
Plasma protein binding of maprotiline in geriatric patients--influence of alpha1-acid glycoprotein [proceedings]. Br J Clin Pharmacol.
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Maprotiline metabolism appears to co-segregate with the genetically ...
Maprotiline metabolism appears to co-segregate with the genetically-determined CYP2D6 polymorphic hydroxylation of debrisoquine. ... maprotiline and this ...
[45]
Cytochrome P‐450 Enzymes Contributing to Demethylation of ...
May 20, 2002 · Formation rates of desmethylmaprotiline were consistent with a two enzyme model with a high (KM=71 and 84 μM) and a low (KM=531 and 426 μM) ...
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Maprotiline – Knowledge and References - Taylor & Francis
Maprotiline is a tetracyclic antidepressant. The frequency of congenital anomalies was not increased among 107 pregnancies exposed to maprotiline during the ...<|separator|>
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Maprotiline - wikidoc
Jun 3, 2014 · Pregnancy. Pregnancy Category (FDA): B Reproduction studies have been performed in female laboratory rabbits, mice, and rats at doses up to 1.3 ...
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Maprotiline CAS#: 10262-69-8 - ChemicalBook
Melting point, 92-94°. Boiling point, 410.26°C (rough estimate). Density, 0.9801 (rough estimate). refractive index, 1.4900 (estimate). pka, pKa 10.5±0.2(H2O t= ...
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Maprotiline Hydrochloride - LKT Labs
Maprotiline acts as an antagonist at norepinephrine transporters (NET), H1 histamine receptors, 5-HT2 receptors, α1-adrenergic receptors, muscarinic ...
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Studies on photodegradation process of psychotropic drugs: a review
Sep 30, 2016 · According to recent studies, photocatalysis could be considered as the most promising and far more effective than regular photolysis.<|control11|><|separator|>
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[PDF] Stability-indicating ultra-fast liquid chromatographic analysis of ...
Maprotiline hydrochloride was purchased from Sigma-Aldrich. ... nm and the column temperature was set at 25 oC. The pH was measured by WTW pH 526 digital pH meter ...
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Maprotiline
Schmidt et al., US 3399201 (1968 to Ciba). Synthesis, NMR, mass spectra: M. Wilhelm, P. Schmidt, Helv. Chim. Acta 52, 1385 (1969). Toxicity: R. Hess et al., ...
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https://www.drugfuture.com/chemdata/maprotiline.html
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Targeting the akt/mtor signaling pathway by maprotiline leads to ...
Sep 2, 2025 · In this study, we demonstrated for the first time that maprotiline significantly inhibits proliferation and migration while promoting apoptosis ...
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Maprotiline - brand name list from Drugs.com
Maprotiline (Ingredient). Chemical formula: C20H23N Drugbank ID: DB00934 ATC code: N06AA21. The information below refers to products available in the United ...Missing: IUPAC molecular classification<|control11|><|separator|>
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https://www.drugs.com/ingredient/maprotiline.html
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[PDF] Controlled Substances - Alphabetical Order
approved for marketing by the U.S. Food and Drug. Administration. 7365. ||. N. Syndros. Drostanolone (17ẞ-hydroxy-2a-methyl-5a-androstan-3- one). 4000. |||. N.Missing: Maprotiline | Show results with:Maprotiline
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Teva-Maprotiline Factsheet, Uses & Common Side Effects | Rexall
Maprotiline can be taken with food or on an empty stomach, and the total daily dose can be taken at one time, if preferred. Many things can affect the dose ...Missing: administration | Show results with:administration
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Maprotiline | Marketing Authorisations | MA | Europe
List of Marketing Authorisations (MA) containing Maprotiline registered and approved in Europe on PharmaCompass.com.Missing: generics | Show results with:generics
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Maprotiline Reviews & Ratings - Drugs.com
I used it until the manufacturer discontinued it. I have tried three other antidepressants, and the side effects were so bad that I completely discontinued them ...Missing: 2021 | Show results with:2021
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Maprotiline Hydrochloride API Charting Growth Trajectories
May 13, 2025 · With a current market size estimated at $250 million in 2025 and a Compound Annual Growth Rate (CAGR) of 5%, the market is poised to reach ...Missing: discontinuation | Show results with:discontinuation
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Top European Maprotiline API GMP Manufacturers (2025)
Similar to TCAs, maprotiline inhibits neuronal norepinephrine reuptake, possesses some anticholinergic activity, and does not affect monoamine oxidase activity.Missing: indications | Show results with:indications