fluvoxamine maleate
Luvox

Available forms
Available by prescription only
Tablets: 25 mg, 50 mg, 100 mg

Indications and dosages
 Obsessive-compulsive disorder. Adults: Initially, 50 mg P.O. daily h.s. Increase in 50-mg increments q 4 to 7 days until maximum benefit occurs. Maximum daily dose is 300 mg. Give total daily doses exceeding 100 mg in two divided doses.
Children ages 8 to 17: 25 mg P.O. h.s. Increase in 25-mg increments q 4 to 7 days until maximum benefit occurs. Maximum daily dose is 200 mg. Give total daily doses exceeding 50 mg in two divided doses.
≡ Dosage adjustment. Because elderly patients and patients with hepatic impairment may have decreased clearance of fluvoxamine maleate, dosage adjustment may be appropriate.

Pharmacodynamics
Anticompulsive action: The exact mechanism of action is unknown. Fluvoxamine is a potent selective inhibitor of the neuronal uptake of serotonin, which is thought to reduce obsessive-compulsive behavior.

Pharmacokinetics
Absorption: Absolute bioavailability of drug is 53%.
Distribution: Mean apparent volume of distribution is about 25 L/kg. About 80% of drug is bound to plasma protein (mostly albumin).
Metabolism: Extensively metabolized in the liver mostly by oxidative demethylation and deamination.
Excretion: Metabolites are primarily excreted in urine.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug or to other phenylpiperazine antidepressants and patients who have taken an MAO inhibitor within 14 days. Use cautiously in patients with hepatic dysfunction, conditions that may affect hemodynamic responses or metabolism, or a history of mania or seizures.

Interactions
Drug-drug. Benzodiazepines, theophylline, warfarin: Reduces clearance of these drugs. Use together cautiously.
Carbamazepine, clozapine, methadone, metoprolol, propranolol, tricyclic antidepressants: Increases fluvoxamine levels. Use together cautiously, and monitor patient closely for adverse reactions. Dosage adjustments may be needed.
Diazepam: Decreases diazepam clearance. Don’t use together.
Diltiazem: May cause bradycardia. Monitor patient’s heart rate.
Lithium, tryptophan: May enhance fluvoxamine effects. Use together cautiously.
MAO inhibitors: May cause severe excitation, hyperpyrexia, myoclonus, delirium, and coma. Avoid use together or within 2 weeks of each other.
Drug-lifestyle. Smoking: May decrease drug effectiveness. Discourage smoking.

Adverse reactions
CNS: headache, asthenia, somnolence, insomnia, nervousness, dizziness, tremor, anxiety, hypertonia, agitation, depression, CNS stimulation.
CV: palpitations, vasodilation.
EENT: amblyopia.
GI: nausea, diarrhea, constipation, dyspepsia, anorexia, vomiting, flatulence, dysphagia, dry mouth, taste perversion.
GU: abnormal ejaculation, urinary frequency, impotence, anorgasmia, urine retention.
Metabolic: hyponatremia.
Respiratory: upper respiratory tract infection, dyspnea, yawning.
Skin: sweating.
Other: decreased libido, flulike syndrome, chills, tooth disorder, SIADH.

Effects on lab test results
• May decrease sodium levels.

Overdose and treatment
Common signs and symptoms of fluvoxamine overdose include drowsiness, vomiting, diarrhea, and dizziness. Coma, tachycardia, bradycardia, hypotension, ECG abnormalities, liver function abnormalities, and seizures may also occur. Symptoms such as aspiration pneumonitis, respiratory difficulties, or hypokalemia may occur because of loss of consciousness or vomiting.
 Treatment is supportive. Besides maintaining an open airway and monitoring vital signs and ECG, administration of activated charcoal may be as effective as emesis or lavage. Because absorption with overdose may be delayed, measures to minimize absorption may be needed for up to 24 hours after ingestion. Dialysis isn’t believed to be beneficial.

Special considerations
• Use cautiously in patients with hepatic dysfunction, other conditions that may affect hemodynamic responses or metabolism, or history of mania or seizures.
 ALERT Record mood changes. Monitor patient for suicidal tendencies, and provide only a minimum supply of drug.
 ALERT Don’t confuse Luvox with Lasix or fluvoxamine with fluoxetine.
Pregnant patients
• Don’t give drug to pregnant women.
Breast-feeding patients
• Drug appears in breast milk. Don’t use in breast-feeding women.
Pediatric patients
• Safety and efficacy in children younger than age 8 haven’t been established.
Geriatric patients
• Drug clearance is decreased by about 50% in elderly patients compared with younger patients. Administer drug cautiously in this age group and adjust dosage slowly during initiation of therapy.

Patient education
• Warn patient not to engage in hazardous activities that require mental alertness and coordination until CNS effects are known.
• Urge patient to avoid alcoholic beverages.
• Alert patient that smoking may decrease drug effectiveness.
• Inform patient that several weeks of therapy may be needed to obtain full antidepressant effect. Once improvement is seen, advise patient not to stop drug until directed.
• Advise patient to report use of herbal remedies or OTC medications because of possible drug interactions.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use