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Sinequan Side Effects

Generic name: doxepin

Medically reviewed by Drugs.com. Last updated on Oct 2, 2024.

Note: This document provides detailed information about Sinequan Side Effects associated with doxepin. Some dosage forms listed on this page may not apply specifically to the brand name Sinequan.

Applies to doxepin: oral capsule, oral solution, oral tablet.

Important warnings This medicine can cause some serious health issues

Oral route (capsule; solution)

Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies with major depressive disorder (MDD) and other psychiatric disorders.

Short term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24, and there was a reduction in risk with antidepressants compared with placebo in adults aged 65 or older.

This risk must be balanced with the clinical need.

Monitor patients closely for clinical worsening, suicidality, or unusual changes in behavior.

Families and caregivers should be advised of the need for close observation and communication with the prescriber.

Not approved for use in pediatric patients.

Serious side effects of Sinequan

Along with its needed effects, doxepin (the active ingredient contained in Sinequan) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking doxepin:

Incidence not known

  • agitation
  • black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • blurred vision
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • canker sores
  • chest pain or tightness
  • chills
  • clay-colored stools
  • cold sweats
  • confusion about identity, place, and time
  • cool, pale skin
  • cough or hoarseness
  • dark urine
  • decrease in the frequency of urination
  • decrease in urine volume
  • decreased urine output
  • depression
  • difficulty in passing urine (dribbling)
  • difficulty with breathing
  • difficulty with speaking
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • drooling
  • dry mouth
  • fast, pounding, or irregular heartbeat or pulse
  • feeling of warmth
  • fever
  • flushed, dry skin
  • fruit-like breath odor
  • general feeling of tiredness or weakness
  • headache
  • hearing loss
  • hostility
  • increased hunger
  • increased thirst
  • increased urination
  • irritability
  • itching or rash
  • lethargy
  • lip smacking or puckering
  • loss of appetite
  • loss of balance control
  • loss of bladder control
  • lower back or side pain
  • mood or mental changes
  • muscle spasm or jerking of all extremities
  • muscle trembling, jerking, or stiffness
  • muscle twitching
  • nausea
  • nervousness
  • nightmares
  • noisy breathing
  • painful or difficult urination
  • pinpoint red spots on the skin
  • pounding in the ears
  • puffing of the cheeks
  • rapid or worm-like movements of the tongue
  • rapid weight gain
  • redness of the face, neck, arms, and occasionally, upper chest
  • restlessness
  • ringing or buzzing or other unexplained noise in the ears that continues
  • seeing, hearing, or feeling things that are not there
  • seizures
  • shakiness and unsteady walk
  • shakiness in the legs, arms, hands, or feet
  • shuffling walk
  • sore throat
  • sores, ulcers, or white spots on the lips, tongue, or in the mouth
  • slurred speech
  • stiffness of the limbs
  • stomach pain
  • stupor
  • sudden loss of consciousness
  • sweating
  • swelling of the face, ankles, or hands
  • swollen glands
  • trouble breathing
  • twisting movements of the body
  • uncontrolled chewing movements
  • uncontrolled movements, especially of the arms, face, legs, neck, and back
  • unexplained weight loss
  • unpleasant breath odor
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting of blood
  • yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking doxepin:

Symptoms of overdose

Other side effects of Sinequan

Some side effects of doxepin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

  • change in taste or bad, unusual or unpleasant (after) taste
  • decreased interest in sexual intercourse
  • diarrhea
  • difficulty having a bowel movement (stool)
  • enlargement of the breasts
  • gas in the stomach
  • hair loss or thinning of the hair
  • heartburn
  • inability to have or keep an erection
  • increased in sexual ability, desire, drive, or performance
  • increased interest in sexual intercourse
  • increased sensitivity of the skin to sunlight
  • loss in sexual ability, desire, drive, or performance
  • redness or other discoloration of the skin
  • severe sunburn
  • swelling of the breasts or breast soreness in both females and males
  • swelling of the testicles
  • unexpected or excess milk flow from breasts
  • weight loss

For healthcare professionals

Applies to doxepin: oral capsule, oral concentrate, oral tablet.

General adverse events

Capsules and Oral Concentrate: The most frequently reported side effects were constipation, dry mouth, and drowsiness.

Tablets (3 and 6 mg): The most frequently reported side effects were somnolence/sedation, nausea, and upper respiratory tract infection.[Ref]

Nervous system

Cardiovascular

Gastrointestinal

Respiratory

Psychiatric

Other

Endocrine

Oncologic

Genitourinary

Hematologic

Hepatic

Musculoskeletal

Dermatologic

Immunologic

Metabolic

Ocular

References

1. (2002) "Product Information. Sinequan (doxepin)." Roerig Division

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

4. (2010) "Product Information. Silenor (doxepin)." Somaxon Pharmaceuticals

Frequently asked questions

Further information

Sinequan side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.