Sinequan Side Effects

Generic name: doxepin

Medically reviewed by Drugs.com. Last updated on Jun 27, 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.

Precautions

It is very important that your doctor check the progress of you or your child at regular visits to allow for changes in the dose and to check for any unwanted effects.

For some children, teenagers, and young adults, this medicine can increase thoughts of suicide. Tell your doctor or your child's doctor right away if you or your child start to feel more depressed and have thoughts about hurting yourself. Report any unusual thoughts or behaviors that trouble you or your child, especially if they are new or are getting worse quickly. Make sure the doctor knows if you or your child have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell the doctor if you or your child have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. Let the doctor know if you or anyone in your family has bipolar disorder (manic-depressive illness) or has tried to commit suicide.

Do not take doxepin (the active ingredient contained in Sinequan) if you have taken a monoamine oxidase (MAO) inhibitor (eg, isocarboxazid [Marplan®], phenelzine [Nardil®], selegiline [Eldepryl®], or tranylcypromine [Parnate®]) in the past 2 weeks. If you do, you may have confusion, agitation, restlessness, stomach or intestinal symptoms, a sudden high body temperature, an extremely high blood pressure, or severe convulsions.

If you or your child are using this medicine for depression or anxiety, do not stop taking it without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help prevent a possible worsening of your condition and reduce the possibility of withdrawal symptoms, such as headache, nausea, or a general feeling of discomfort or illness.

Silenor® tablets may cause sleep-related behaviors such as driving a car (sleep-driving), walking (sleep-walking), having sex, making phone calls, or preparing and eating food while asleep or not fully awake. If any of these reactions occur, tell your doctor right away.

If you think you need to take Silenor® tablets for 7 to 10 days, talk to your doctor.

This medicine may cause some people to become drowsy. Make sure you know how you react to this medicine before you drive, use medicines, or do anything else that could be dangerous if you are drowsy or not alert.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, allergies, or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. This effect may last for a few days after you Stop taking doxepin. Check with your doctor before taking any of the above while you or your child are using this medicine.

Tell your doctor if you are pregnant or planning to become pregnant during treatment with this medicine. This medicine may cause symptoms of sedation (eg, breathing problems, sluggishness, low muscle tone, feeding problems, or withdrawal symptoms) in the baby during the third trimester.

Talk with your doctor before using this medicine if you plan to have children. Some men and women who use this medicine have become infertile (unable to have children).

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines) and herbal or vitamin supplements.

Serious side effects of Sinequan

Along with its needed effects, doxepin 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:

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

Symptoms of overdose

• clumsiness
• disturbed concentration
• drowsiness
• enlarged pupils
• increased or excessive unconscious or jerking movements
• low body temperature
• muscle aches
• muscle weakness
• shivering
• sleepiness
• weak or feeble pulse
• weight gain

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:

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

• Common (1% to 10%): Somnolence/sedation
• Frequency not reported: Drowsiness, numbness, paresthesia, ataxia, extrapyramidal symptoms, seizure, tardive dyskinesia, tremor, dizziness, headache, neuroleptic malignant-like syndrome, convulsion, hyperreflexia in neonate, lethargy, syncope, ageusia, cerebrovascular accident, disturbance in attention, migraine, sleep paralysis, syncope vasovagal
• Postmarketing reports: Hypoesthesia, dysgeusia^[Ref]

Cardiovascular

• Common (1% to 10%): Hypertension
• Frequency not reported: Hypotension, flushing, tachycardia, ECG changed, postural hypotension, atrioventricular block, palpitation, ventricular extrasystole, ECG ST-T segment abnormal, ECG QRS complex abnormal, heart rate decreased, QRS axis abnormal, pallor, blood pressure inadequately controlled, hematoma, hot flush
• Postmarketing reports: Arrhythmia, conduction disorder^[Ref]

Gastrointestinal

• Common (1% to 10%): Gastroenteritis, nausea
• Frequency not reported: Dry mouth, constipation, vomiting, indigestion, taste disturbance, diarrhea, anorexia, aphthous stomatitis, abdominal pain, gastroesophageal reflux disease, dyspepsia, gingival recession, hematochezia, lip blister
• Postmarketing reports: Tongue edema, upper abdominal pain^[Ref]

Respiratory

• Common (1% to 10%): Upper respiratory tract infection/nasopharyngitis
• Frequency not reported: Asthma exacerbated, respiratory depression in neonate, bronchitis, laryngitis, sinusitis, lower respiratory tract infection, pharyngitis, pneumonia, nasal congestion, pharyngolaryngeal pain, sinus congestion, wheezing, cough, crackles lung, nasopharyngeal disorder, rhinorrhea, dyspnea^[Ref]

Psychiatric

• Frequency not reported: Confusion, disorientation, hallucination, libido decreased, libido increased, withdrawal symptom, agitation, anxiety, nervousness, aggressive reaction, suicidal ideation, suicidal behavior, insomnia, nightmare, mania exacerbated, paranoid delusions exacerbated, dream abnormal, adjustment disorder, depression, elevated mood^[Ref]

Other

• Frequency not reported: Edema, tinnitus, weight gain, chills, fatigue, weakness, hyperpyrexia, asthenia, bone fracture, drug tolerance, ear pain, hypoacusis, motion sickness, tympanic membrane perforated, chest pain, gait abnormal, peripheral edema, fungal infection, tooth infection, viral infection, cellulitis staphylococcal, folliculitis, gastroenteritis viral, herpes zoster, infective tenosynovitis, influenza, onychomycosis, back injury, fall, joint sprain, skin laceration, sensation of heaviness, arthrodesis
• Postmarketing reports: Malaise^[Ref]

Endocrine

• Frequency not reported: Gynecomastia, breasts enlarged, galactorrhea, testicular swelling, syndrome of inappropriate antidiuretic hormone^[Ref]

Oncologic

• Frequency not reported: Lung adenocarcinoma stage I, malignant melanoma, breast cyst^[Ref]

Genitourinary

• Frequency not reported: Urinary retention, urinary tract infection, dysmenorrhea, dysuria, enuresis, hemoglobinuria, nocturia^[Ref]

Hematologic

• Frequency not reported: Eosinophilia, bone marrow depression, agranulocytosis, leukopenia, thrombocytopenia, hemolytic anemia, thrombocythemia, anemia, neutrophil count decreased^[Ref]

Hepatic

• Frequency not reported: Jaundice, hepatitis, hepatic abnormality, hyperbilirubinemia, ALT increased, transaminases increased^[Ref]

Musculoskeletal

• Frequency not reported: Arthralgia, back pain, myalgia, neck pain, pain in extremity, muscle cramp, joint range of motion decreased^[Ref]

Dermatologic

• Frequency not reported: Rash, pruritus, photosensitivity, purpura, sweating, alopecia, face edema, urticaria, hyperhidrosis, cold sweat, skin irritation, dermatitis, erythema, rosacea^[Ref]

Immunologic

• Frequency not reported: Hypersensitivity^[Ref]

Metabolic

• Frequency not reported: Blood sugar increased, blood sugar decreased, appetite increased, anorexia, appetite decreased, hyperkalemia, hypermagnesemia, hypokalemia^[Ref]

Ocular

• Frequency not reported: Vision blurred, angle closure glaucoma, mydriasis, intraocular pressure increased, eye redness, blepharospasm, diplopia, eye pain, lacrimation decreased, eye infection^[Ref]

See also:

Frequently asked questions

• What are the strongest sleeping pills?
• What are some common side effects of antidepressants?

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.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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