Mianserin

Antidepressant Drug

Drug class: Atypical Antidepressants

Mianserin (TOLVON)（中文：米安舍林）

Pronunciation

Mianserin 10mg

Mianserin 30mg

Common Strengths of Mianserin

Mianserin are available in the following strengths:

• 10 mg
• 30 mg

Drug Trade Names of Mianserin

Tolvon

Drug Usage

• Mainserin is primarily used to treat major depressive disroder (MDD).
• Off-label uses: anxiety and insomnia

Mechanism of Action

Mianserin works by antagonizing central presynaptic alpha-2 adrenergic receptors, which increase the release of norepinephrine and serotonin. It also blocks certain serotonin receptors (5-HT2 and 5-HT3), contributing to its antidepressant effects.

Route of Administration

Oral

Dosages

• Inital dose: 30 mg to 40 mg per day, which may be increased gradually based on clinical response.
• Maintenance dose: Typically, between 30 mg and 90 mg per day, taken as single dose at bedtime or divided into multiple doses.

Side Effects

Frequency	Adverse reactions
Common	Drowsiness: Often the most common side effect, particularly in the initial days of treatment.
	Dry Mouth: May improve with sugar-free gum or sweets.
	Constipation: Dietary adjustments, such as increased fiber intake, can help.
	Blurred Vision: Patient are advised to avoid driving or operating machinery until they know how the medication affects them.
	Postural Hypotension: A drop in blood pressure upon standing can lead to dizziness or fainting.
	Nausea and Vomiting: Simple meals and hydration can mitigate these symptoms.
	Increased Appetite and Weight Gain: This is often related to its antihistaminic effects.
Serious	Suicidal Ideation: Increased risk of suicidal thoughts and behavior, particularly during the early stages of treatment or after discontinuation.
	Serotonin syndrome (confusion, fast heart rate, agitation)
	Agranulocytosis (severe reduction in white blood cells). Typcially occurring after 4-6 weeks of treatment. Regular blood counts are recommended during this period.
	QT prolongation which may lead to irregular heartbeats and fainting.
	Liver Dysfunction: Disturbances in liver function and mild jaundice have been reported.
	Convulsions: Seizures may occur, necessitating discontinuation of the drug.
	Psychotic Symptoms: Exacerbation of mania or paranoid delusions in predisposed individuals

Pharmacokinetics

• Absorption: Mianserin is readily absorbed from the gastrointestinal tract, but its bioavailability is reduced due to extensive first-pass metabolism in the liver, typically ranging from 20% to 30%.
• Metabolism: Extensively metabolized in the liver primarily by CYP2D6 and CYP3A4.
• The eliminatioin half-life of mianserin varies significantly:
  • In younger adults, the terminal elimination half-life is approximately 9.6 hours
  • In elderly patients, this half-life can extend to about 27 hours, indicating slower clearance in this population
• Onset Time: Effects may be observed within 1 to 2 weeks, but full therapeutic effects may take 4 to 6 weeks.

Drug Precautions

Pregnancy

Use only if the benefits outweigh risks.

Breastfeeding

Excreted in breast milk; caution is advised.

Children and Elderly

Not approved for pediatric use; elderly patients may experience increased sensitivity and require dose adjustments.

Monitoring Requirements

Monitor for signs of agranulocytosis, liver function, and symptoms of serotonin syndrome.

Drug Interactions

• Antidepressants: Caution is advised when combined with other antidepressants, particularly those that affect serotonin levels, as this can increase the risk of serotonin syndrome.
• Anticoagulants: Can interact with anticoagulants like warfarin, necessitating close monitoring of coagulation parameteres due to potential changes in blood clotting.
• Antipeileptics: Drugs like phenytoin and carbamazepine may reduce the plasma concentration of mianserin, potentially diminishing its therapeutic effects.
• Antiepileptics: Drugs like phenytoin and carbamazepine may reduce the plasma concentration of mianserin, potentially diminishing its therapeutic effects.
• Centrally Acting Antihypertensives: Mianserin may enhance the hypotensive effects of medications like hydralazine leading to significant drops in blood puressure.
• Benzodiazepines and CNS Depressants:
  • The sedative effects of mianserin can be potentiated when used with benzodiazepines, alcohol, or other central nervous system depressants

FAQ

How Should I Take the Tablet?

Take mianserin usually once daily at bedtime. It can be taken with or without food.

What Should I Avoid While Taking?

Avoid alcohol, as it can increase side effects. Be cautions when driving or operating machinery until you know how mianserin affects you.

What Happens if I Miss a Dose?

Take the missed dose as soon as you remember, but skip it if it is almost for your next dose. Do not take two doses at once.