Generic name: Doxepin hydrochloride.

Other brand name: Adapin.

Sinequan is a tricyclic antidepressant. It is thought to relieve depression by increasing the concentration of chemicals necessary for nerve transmissions in the brain.

Quick Facts About Sinequan


Used to treat depression and anxiety. It relieves tension, improves sleep, elevates mood, increases energy, and eases feelings of fear, guilt, apprehension, and worry. Effective when depression is psychological, associated with alcoholism, or a result of another disease or psychotic depressive disorders.

Sinequan Dosage

Take exactly as prescribed. May take several weeks to observe effects of medication.

  • Usual adult dose: mild to moderate illness — 75 milligrams per day. Range may be from 25 to 150 milligrams per day, depending on an individual’s needs 150-milligram capsule for long-term therapy only, and not as a starting dose. More severe illness — may be prescribed up to 300 milligrams per day. Seniors — dosage is carefully adjusted by your doctor.
  • Usual child dose: not generally prescribed for children under 12 years.
  • Missed dose: if taking several doses per day — take as soon as possible; then take remaining doses for the day at evenly spaced intervals. If almost time for next dose, do not take missed dose; go back to regular schedule. If taking single dose at bedtime — if it is the next morning, skip missed dose and return to regular schedule. Do not double doses.

Sinequan Side Effects

Overdose symptoms:

blurred vision, coma, convulsions, decreased intestinal movement, dilated pupils, drowsiness, excessive mouth dryness, high or low body temperature, irregular or rapid heartbeat, low or high blood pressure, overactive reflexes, severe breathing problems, stupor, urinary problems. If you suspect an overdose, immediately seek medical attention.

Most common side effect: drowsiness.

Less common or rare Sinequan side effects: blurred vision, breast development in males, bruises, buzzing or ringing in ears, changes in sex drive, chills, confusion, constipation, diarrhea, difficulty urinating, disorientation, dizziness, dry mouth, enlarged breasts, fatigue, fluid retention, flushing, fragmented or incomplete movements, hair loss, hallucinations, headache, high fever, high or low blood sugar, inappropriate breast milk secretion, indigestion, inflammation of mouth, itching and skin rash, lack of muscle control, loss of appetite, loss of coordination, low blood pressure, nausea, nervousness, numbness, poor bladder control, rapid heartbeat, red or brownish skin spots, seizures, sensitivity to light, severe muscle stiffness, sore throat, sweating, swelling of testicles, taste disturbances, tingling sensation, tremors, vomiting, weakness, weight gain, yellow eyes and skin.


Do not take MAO inhibitors such as Nardil and Parnate with Sinequan; may result in death.

Inform your doctor before combining Sinequan with:

amphetamines such as Dexedrine; antihistamines such as Benadryl and Tavist; baclofen (Lioresal); benztropine (Cogentin); carbamazepine (Tegretol); central nervous system depressants such as Darvon and Xanax; cimetidine (Tagamet); clonidine (Catapres); epinephrine (EpiPen); fluoxetine (Prozac); guanethidine (Ismelin); quinidine (Quinidex); tolazamide (Tolinase). Also inform your doctor of any nonprescription medications you are taking.

Do not drink alcohol during Sinequan therapy.

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. May appear in breast milk could affect a nursing infant.

Seniors should use with caution.

Not generally prescribed for children under 12 years.

  • Do not take if you have glaucoma or difficulty urinating unless directed by your doctor.
  • May cause drowsiness and impair your ability to drive a car or operate machinery. Do not take par tin any activity that requires alertness.
  • Avoid if sensitive to or allergic to this medication or similar antidepressants.
  • May decrease seizure threshold.
  • Inform your doctor or dentist in medical emergency or before surgery that you are taking Sinequan.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Sinequan side effects, please contact your healthcare provider