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

Applies to nefazodone: oral tablet.

Serious side effects of Serzone

Along with its needed effects, nefazodone (the active ingredient contained in Serzone) 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 as soon as possible if any of the following side effects occur while taking nefazodone:

More common

• Blurred vision or other changes in vision
• clumsiness or unsteadiness
• lightheadedness or fainting
• ringing in the ears
• skin rash or itching

Less common

• Bladder pain
• bloody or cloudy
• cough or hoarseness
• diarrhea
• excessive muscle tone
• eye pain
• feeling dizzy
• frequent urge to urinate
• itching of the vagina or genital area
• muscle stiffness
• muscle tension or tightness
• nausea
• pain during sexual intercourse
• painful, burning, or difficult urination
• shortness of breath, tightness in chest, or wheezing
• stomach pain
• thick, white vaginal discharge with no odor or with a mild odor
• troubled breathing

Rare

• Asthma
• bleeding from the rectum
• bloody or black, tarry stools
• change in sexual desire or performance
• chest pain
• double vision
• dryness of eye
• ear pain
• fainting
• fast heartbeat
• fever, chills, or sore throat
• hallucinations (seeing, hearing, or feeling things that are not there)
• hives
• increased sense of hearing
• increased sensitivity to sun
• irritation or soreness of mouth
• joint or muscle pain or stiffness
• kidney stones
• large pupils of eyes
• lower back, side, or stomach pain
• menstrual changes
• mood or mental changes
• nerve pain or twitching
• pelvic pain
• problems in speaking
• problems with urination
• prolonged, painful, inappropriate penile erection
• red or irritated eyes
• sensitivity of eyes to light
• swelling of face
• swollen glands
• talking, feeling, and acting with excitement and activity you cannot control
• unusual bleeding or bruising
• unusual feeling of well-being
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds

Incidence not known

• Blistering, peeling, or loosening of skin
• light-colored stools
• confusion
• dark urine
• decreased urine output
• fever
• increased thirst
• itching
• lack of appetite
• large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• muscle pain or cramps
• muscle spasm or jerking of all extremities
• muscle stiffness
• pain, warmth, or burning in fingers, toes, and legs
• red skin lesions, often with a purple center
• sore throat
• sudden loss of consciousness
• sweating
• vomiting

Other side effects of Serzone

Some side effects of nefazodone 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:

More common

• Abnormal dreams
• agitation
• confusion
• constipation
• diarrhea
• dizziness
• drowsiness
• dryness of mouth
• flushing or feeling of warmth
• headache
• heartburn
• increased appetite
• increased cough
• memory problems
• nausea
• swelling of arms or legs
• tingling, burning, or prickly sensations
• tremor
• trouble in sleeping
• vomiting

Less common or rare

• Breast pain
• generalized slowing of mental and physical activity
• increased thirst
• loss of strength or energy
• muscle weakness

Incidence not known

• Unexpected or excess milk flow from breasts
• swelling of the breasts or breast soreness in males

For Healthcare Professionals

Applies to nefazodone: oral tablet.

General

The most commonly reported side effects were headache, somnolence, dry mouth, and nausea.^[Ref]

Nervous system

Very common (10% or more): Headache (up to 36%), somnolence (up to 28%), dizziness (up to 22%), lightheadedness (up to 10%)

Common (1% to 10%): Ataxia, decreased concentration, hypertonia, incoordination, memory impairment, paresthesia, taste perversion, tremor

Uncommon (0.1% to 1%): Abnormal gait, decreased attention, dysarthria, hangover effect, myoclonus, neuralgia, twitching, vertigo

Rare (less than 0.1%): Cerebrovascular accident, hyperesthesia, hyperkinesia, hypotonia, neuroleptic malignant syndrome, taste loss

Frequency not reported: Central nervous system stimulation, hypesthesia, migraine

Postmarketing reports: Convulsions, grand mal seizures, serotonin syndrome^[Ref]

Gastrointestinal

Very common (10% or more): Dry mouth (up to 25%), nausea (up to 23%), constipation (up to 17%)

Common (1% to 10%): Diarrhea, dyspepsia, gastroenteritis, vomiting

Uncommon (0.1% to 1%): Colitis, enlarged abdomen, eructation, esophagitis, gastritis, gingivitis, halitosis, mouth ulceration, peptic ulcer, periodontal abscess, rectal hemorrhage, stomatitis

Rare (less than 0.1%): Dysphagia, gastrointestinal hemorrhage, glossitis, increased salivation, oral moniliasis, ulcerative colitis

Frequency not reported: Abdominal pain, flatulence, tooth disorder^[Ref]

Other

Very common (10% or more): Asthenia (up to 11%)

Common (1% to 10%): Chills, fever, tinnitus

Uncommon (0.1% to 1%): Ear pain, hernia, malaise

Rare (less than 0.1%): Deafness

Frequency not reported: Accidental injury, pain^[Ref]

Psychiatric

Very common (10% or more): Insomnia (up to 11%)

Common (1% to 10%): Abnormal dreams, agitation, confusion, decreased libido, psychomotor retardation

Uncommon (0.1% to 1%): Abnormal thinking, apathy, depersonalization, derealization, euphoria, hallucinations, hostility, increased libido, paranoid reaction, suicidal thoughts, suicide, suicide attempt

Rare (less than 0.1%): Anorgasmia

Frequency not reported: Anxiety, depression, dysphoria, emotional lability^[Ref]

Ocular

In clinical trials, scotomata and visual trails did not occur in patients given doses below 300 mg/day; however, these events were reported at doses below 300 mg/day in postmarketing experience.^[Ref]

Very common (10% or more): Abnormal vision (up to 10%)

Common (1% to 10%): Blurred vision, eye pain, scotoma, visual field defect, visual trails

Uncommon (0.1% to 1%): Abnormality of accommodation, conjunctivitis, diplopia, dry eye, hyperacusis, keratoconjunctivitis, mydriasis, photophobia

Rare (less than 0.1%): Angle-closure glaucoma, night blindness, ptosis^[Ref]

Cardiovascular

Common (1% to 10%): Feeling warm, flushing, hypotension, peripheral edema, postural hypotension, sinus bradycardia, vasodilatation

Uncommon (0.1% to 1%): Angina pectoris, hypertension, syncope, tachycardia, ventricular extrasystoles

Rare (less than 0.1%): Atrioventricular (AV) block, congestive heart failure, hemorrhage, pallor, varicose veins

Frequency not reported: Chest pain, edema, palpitation^[Ref]

Genitourinary

Common (1% to 10%): Breast pain, impotence, urinary frequency, urinary retention, urinary tract infection, vaginitis

Uncommon (0.1% to 1%): Abnormal ejaculation, amenorrhea, breast enlargement, hematuria, menorrhagia, metrorrhagia, nocturia, pelvic pain, polyuria, urinary incontinence, urinary urgency, vaginal hemorrhage

Rare (less than 0.1%): Enlarged uterine fibroids, oliguria, uterine hemorrhage

Frequency not reported: Dysmenorrhea, dysuria

Postmarketing reports: Galactorrhea, priapism^[Ref]

Respiratory

Common (1% to 10%): Bronchitis, dyspnea, increased cough, pharyngitis

Uncommon (0.1% to 1%): Asthma, epistaxis, hiccup, laryngitis, pneumonia, voice alteration

Rare (less than 0.1%): Hyperventilation, yawn

Frequency not reported: Rhinitis, sinusitis^[Ref]

Dermatologic

Common (1% to 10%): Pruritus, rash

Uncommon (0.1% to 1%): Acne, alopecia, dry skin, ecchymosis, eczema, face edema, maculopapular rash, photosensitivity reaction, urticaria, vesiculobullous rash

Rare (less than 0.1%): Cellulitis

Frequency not reported: Sweating

Postmarketing reports: Stevens-Johnson syndrome^[Ref]

Metabolic

Common (1% to 10%): Increased appetite, thirst

Uncommon (0.1% to 1%): Dehydration, gout, increased lactic dehydrogenase, weight loss

Rare (less than 0.1%): Hypercholesteremia, hypoglycemia

Frequency not reported: Anorexia, weight gain

Postmarketing reports: Hyponatremia^[Ref]

Musculoskeletal

Common (1% to 10%): Arthralgia, neck rigidity

Uncommon (0.1% to 1%): Arthritis, bursitis, muscle stiffness, tenosynovitis

Rare (less than 0.1%): Tendinous contracture

Frequency not reported: Back pain, cramp, myalgia, neck pain

Postmarketing reports: Rhabdomyolysis^[Ref]

Rhabdomyolysis occurred in patients receiving this drug with lovastatin or simvastatin.^[Ref]

Immunologic

Common (1% to 10%): Flu syndrome, infection^[Ref]

Hematologic

Common (1% to 10%): Decreased hematocrit

Uncommon (0.1 to 1%): Anemia, leukopenia, lymphadenopathy

Postmarketing reports: Thrombocytopenia^[Ref]

Hepatic

Uncommon (0.1% to 1%): Abnormal liver function tests, increased ALT, increased AST

Rare (less than 0.1%): Hepatitis

Postmarketing reports: Liver failure (in some cases leading to liver transplantation and/or death), liver necrosis^[Ref]

Renal

Uncommon (0.1% to 1%): Cystitis, kidney calculus^[Ref]

Hypersensitivity

Uncommon (0.1% to 1%): Allergic reaction

Postmarketing reports: Anaphylactic reactions, angioedema^[Ref]

Endocrine

Postmarketing reports: Gynecomastia, increased prolactin^[Ref]