Doxepin

Reviewed on 10/18/2023

What Is Doxepin and How Does It Work?

Doxepin is recommended for the treatment of:

  • Psychoneurotic patients with depression and/or anxiety
  • Depression and/or anxiety associated with alcoholism (not to be taken concomitantly with alcohol)
  • Depression and/or anxiety associated with organic disease (the possibility of drug interaction should be considered if the patient is receiving other drugs concomitantly)
  • Psychotic depressive disorders with associated anxiety including involutional depression and manic-depressive disorders
  • The target symptoms of psychoneurosis that respond particularly well to doxepin hydrochloride capsules include anxiety, tension, depression, somatic symptoms and concerns, sleep disturbances, guilt, lack of energy, fear, apprehension and worry

Clinical experience has shown that doxepin is safe and well tolerated even in the elderly patient. Owing to lack of clinical experience in the pediatric population, doxepin hydrochloride capsules are not recommended for use in children under 12 years of age.

The Silenor brand of doxepin is indicated for the treatment of insomnia characterized by difficulty with sleep maintenance. The clinical trials performed in support of efficacy were up to 3 months in duration

Doxepin is available under the following different brand names: Silenor.

What Are Dosages of Doxepin?

Dosages of Doxepin:

Dosage Forms and Strengths

Capsule (generic)

  • 10 mg
  • 25 mg
  • 50 mg
  • 75 mg
  • 100 mg
  • 150 mg

Tablet (Silenor)

  • 3 mg
  • 6 mg

Oral concentrate (generic)

  • 10mg/mL

Dosage Considerations – Should be Given as Follows:

  • Children under 12 years old: Not recommended

Depression/Anxiety

  • Initiate at a low dose (25 mg/day); gradually titrate upward every 5-7 days
  • Dosage range: 25-300 mg/day orally, up to 150 mg/day as a single dose
  • If dose exceeds 150 mg/day, divide every 12 hours
  • Dosing considerations
    • May give at bedtime to decrease daytime sedation
    • Geriatric: Lower initial dose (i.e., 10 mg/day) and adjust gradually; 10-25 mg orally at bedtime; may increase by 10-25 mg increments every 3 days for inpatients and weekly for outpatients if tolerated

Insomnia (Silenor)

  • Sleep maintenance
  • Adult: 3-6 mg orally within 30 minutes before bedtime; not to exceed 6 mg/day
  • Hepatic impairment/debilitated patients: 3 mg orally within 30 minutes before bedtime
  • Geriatric starting dose: 3 mg orally within 30 minutes before bedtime; may increase to 6 mg orally at bedtime if clinically indicated

Dosing considerations

  • To minimize the potential for next-day drowsiness, do not take within 3 hours of a meal (AUC increased by 41% and Cmax by 15% when taken with a high-fat meal)

Geriatric:

Dosing Modifications

  • Hepatic impairment: Use lower dose and adjust gradually for depression; initiate Silenor at 3 mg daily for insomnia

What Are Side Effects Associated with Using Doxepin?

Side effects associated with use of Doxepin, include the following:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Doxepin ?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Severe Interactions of doxepin include:
    • astemizole
    • cisapride
    • disopyramide
    • ibutilide
    • indapamide
    • iobenguane I 123
    • isocarboxazid
    • pentamidine
    • phenelzine
    • pimozide
    • procainamide
    • procarbazine
    • quinidine
    • selegiline
    • sotalol
    • terfenadine
    • thioridazine
  • Doxepin has serious interactions with at least 121 different drugs.
  • Doxepin has moderate interactions with at least 321 different drugs.
  • Doxepin has mild interactions with at least 88 different drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Doxepin ?

Warnings

  • In short-term studies, antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults (under 24 years) taking antidepressants for major depressive disorders and other psychiatric illnesses
  • This increase was not seen in patients over 24 years; a slight decrease in suicidal thinking was seen in adults over 65 years
  • In children and young adults, risks must be weighed against the benefits of taking antidepressants
  • Patients should be monitored closely for changes in behavior, clinical worsening, and suicidal tendencies; this should be done during initial 1-2 months of therapy and dosage adjustments
  • The patient's family should communicate any abrupt changes in behavior to the healthcare provider
  • Worsening behavior and suicidal tendencies that are not part of the presenting symptoms may require discontinuation of therapy
  • This drug is not approved for use in pediatric patients
  • This medication contains doxepin
  • Do not take Silenor if you are allergic to doxepin or any ingredients contained in this drug
  • Keep out of reach of children
  • In case of overdose, get medical help or contact a Poison Control Center immediately

Contraindications

  • Contraindications
  • Hypersensitivity
  • Untreated narrow-angle glaucoma
  • Severe urinary retention
  • Within 14 days of MAO inhibitors

Effects of Drug Abuse

  • Overdose may cause EKG QRS widening and risk of dysrhythmias.

Short-Term Effects

  • See "What Are Side Effects Associated with Using Doxepin?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Doxepin?"

Cautions

  • Use caution in BPH, urinary retention, decreased GI motility, hyperthyroidism, seizure disorder, brain tumor, diabetes, hepatic impairment, cardiovascular disease, mania/hypomania, respiratory disease, and seizure disorders
  • Clinical worsening and suicidal ideation may occur despite medication in adolescents and young adults (aged 18-24 years)
  • Risk of anticholinergic side effects
  • Risk of mydriasis; may trigger angle closure attack in patients with angle-closure glaucoma with anatomically narrow angles without a patent iridectomy
  • CNS depressant; can impair alertness and motor coordination; avoid use with other CNS depressants (e.g., alcohol)
  • Overdose may cause EKG QRS widening and risk of dysrhythmias
  • Protect capsules and oral concentrate from direct sunlight
  • Prescriptions should be written for the smallest quantity consistent with good patient care; the patient's family or caregiver should alert healthcare professionals about the emergence of suicidality and related behaviors including agitation, panic attacks, irritability, impulsivity, mania, and insomnia or if worsening depression or psychosis occurs
  • Anticholinergic effects including blurred vision, urinary retention, xerostomia, and constipation may occur
  • Neuropsychiatric symptoms may occur unpredictably including anxiety and psychosis
  • Bone fracture reported with the use of antidepressant therapy; consider the possibility of fracture if a patient presents with unexplained bone pain, joint tenderness, bruising, or swelling
  • May cause orthostatic hypotension; use caution in patients at risk of this effect or that may not tolerate hypotensive episodes (e.g., hypovolemia, cardiovascular or cerebrovascular disease, and others)
  • Sleep-related activities including sleep-driving, eating food, cooking, making phone calls reported; discontinue therapy if the patient reports sleep-related episodes
  • Possibility of EPS and neuroleptic malignant syndrome (NMS)
  • May cause confusion in the elderly; avoid doses greater than 6 mg/day

Pregnancy and Lactation

  • No information is available about the use of Doxepin during pregnancy
  • Consult your doctor
  • Doxepin enters breast milk; it is not recommended for use while breastfeeding
  • The American Academy of Pediatrics (AAP) states Doxepin "may be of concern"
References
SOURCE:
Medscape. Doxepin.
https://reference.medscape.com/drug/silenor-doxepin-342940