Sinequan Side Effects

Generic name: doxepin

Medically reviewed by Drugs.com. Last updated on Oct 21, 2023.

Note: This document contains side effect information about doxepin. Some dosage forms listed on this page may not apply to the brand name Sinequan.

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

Warning

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

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:

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

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]