Doxepin (Oral)

Generic Details

Generic Name

Doxepin-oral

Other Names

  • Sinequan
  • Adapin

Drug Class

  • Tricyclic antidepressant

Chemical Formula

C19H21NO

Molecular Weight

279.376 g/mol

Mechanism of Action

  • Blocks the reuptake of serotonin and norepinephrine

Indications

  • Depression
  • Anxiety disorders
  • Insomnia

Common Dosage Forms

  • Tablet
  • Capsule
  • Liquid

Typical Dosage

  • Depression: 75-150mg daily
  • Insomnia: 3-6mg at bedtime

Pediatric Dosage

  • Safety and efficacy not established in children

Geriatric Dosage

  • Lower starting doses recommended due to increased sensitivity in the elderly

Side Effects

  • Drowsiness
  • Dry mouth
  • Constipation
  • Weight gain
  • Blurred vision

Contraindications

  • Hypersensitivity to doxepin
  • Monoamine oxidase inhibitor (MAOI) use

Pregnancy Category

  • Category C - Risk cannot be ruled out

Lactation Safety

  • May pass into breast milk, use caution

Drug Interactions

  • MAOIs
  • Cimetidine
  • Anticholinergic drugs

Overdose Symptoms

  • Confusion
  • Hallucinations
  • Seizures

Antidote for Overdose

  • Activated charcoal
  • Physostigmine

Storage Conditions

  • Store at room temperature away from light and moisture

Pharmacokinetics

  • Absorption: Rapidly absorbed orally
  • Distribution: Protein-bound, crosses the blood-brain barrier
  • Metabolism: Hepatic via CYP2C19 and CYP2D6
  • Excretion: Primarily renal

Precautions

  • Caution in patients with a history of cardiac arrhythmias or seizures

Warnings

  • May increase suicidal thoughts in young adults

Others

  • Avoid alcohol consumption while taking doxepin.