fluvoxamine maleate

Action

Selectively inhibits serotonin reuptake in neurons. This inhibition is thought to relieve depression and reduce behaviors related to obsessive-compulsive disorder (OCD).

Availability

Capsules (extended-release): 100 mg, 150 mg

Tablets: 25 mg, 50 mg, 100 mg

Indications and dosages

➣ OCD

Adults: Initially, 50 mg P.O. daily at bedtime; may increase by 50 mg q 4 to 7 days until desired effect occurs (not to exceed 300 mg/day). If daily dosage exceeds 100 mg, give in two equally divided doses; if doses aren't equal, give larger dose at bedtime. As needed, adjust dosage periodically to maintain lowest effective dosage that controls symptoms (immediate-release formulation)

Children ages 8 to 17: Initially, 25 mg at bedtime; may increase by 25 mg/day q 4 to 7 days until desired effect occurs (up to 200 mg/day for patients up to age 11 or up to 300 mg for adolescents). If daily dosage exceeds 50 mg, give in divided doses, with larger dose at bedtime (immediate-release formulation).

➣ OCD; social anxiety disorder

Adults: 100 mg P.O. once daily at bedtime; titrate in 50-mg increments weekly, to a maximum of 300 mg/day (extended-release formulation).

Dosage adjustment

• Hepatic impairment

• Elderly patients

Off-label uses

• Autism

• Anxiety disorders

Contraindications

• Hypersensitivity to drug or other SSRIs

• MAO inhibitor use within past 14 days

Precautions

Use cautiously in:

• cardiovascular disease, hepatic or renal impairment, mania, seizures, suicidal tendency

• elderly patients

• labor and delivery

• pregnant or breastfeeding patients.

Administration

• Give with or without food.

• Discontinue 5 weeks before MAO inhibitor therapy is set to begin.

Adverse reactions

CNS: dizziness, drowsiness, headache, insomnia, nervousness, anxiety, apathy, manic or psychotic reactions, depression, hypokinesia or hyperkinesia, tremor, suicide or suicidal ideation (especially in child or adolescent)

CV: hypertension, orthostatic hypotension, palpitations, tachycardia

EENT: sinusitis

GI: nausea, vomiting, diarrhea, constipation, dyspepsia, flatulence, dry mouth, dysphagia, anorexia

GU: decreased libido, sexual dysfunction, anorgasmia

Musculoskeletal: hypertonia, myoclonus, twitching

Respiratory: cough, dyspnea

Skin: diaphoresis

Other: abnormal taste, tooth disorder, dental caries, edema, weight gain or loss, chills, fever, flulike symptoms, yawning, hot flashes, allergic reactions, hypersensitivity reaction

Interactions

Drug-drug. Beta-adrenergic blockers (such as propranolol), carbamazepine, lithium, L-tryptophan, methadone, some benzodiazepines, theophylline, tolbutamide, warfarin: decreased fluvoxamine metabolism, increased effects

Clozapine: increased clozapine blood level and risk of toxicity

MAO inhibitors: serotonin syndrome

Tricyclic antidepressants: increased fluvoxamine blood level

Drug-tests. Hepatic enzyme levels: increased

Drug-behaviors. Smoking: decreased fluvoxamine efficacy

Patient monitoring

See Watch closely for signs and symptoms of depression and suicidal ideation (especially in child or adolescent).

• Assess patient's appetite. Report weight gain or loss.

• Monitor liver function test results.

• Monitor cardiovascular status, particularly blood pressure.

Patient teaching

• Instruct patient to swallow extended-release capsules whole and not to break, crush, or chew them.

See Instruct patient or caregiver (especially with child or adolescent patient) to recognize and immediately report signs of suicidal intent or expressions of suicidal ideation.

• Inform patient that drug may take several weeks to be fully effective.

• Recommend establishing effective bedtime routine to minimize insomnia.

• Instruct female patient to notify prescriber if she becomes or intends to become pregnant. Caution her not to breastfeed.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.