(kloe na' ze pam)
Apo-Clonazepam (CAN), Clonapam (CAN), Gen-Clonazepam (CAN), Klonopin, Klonopin Wafers, Rivotril (CAN)
Pregnancy Category D
Controlled Substance C-IV
Exact mechanisms not understood; benzodiazepines potentiate the effects of GABA, an inhibitory neurotransmitter.
· Used alone or as adjunct in treatment of Lennox-Gastaut syndrome (petit mal variant), akinetic and myoclonic seizures; may be useful in patients with absence (petit mal) seizures who have not responded to succinimides; up to 30% of patients show loss of effectiveness of drug, often within 3 mo of therapy (may respond to dosage adjustment), treatment of panic disorder with or without agoraphobia
· Unlabeled uses: Periodic leg movements during sleep, hypokinetic dysarthria, acute manic episodes, multifocal tic disorders, neuralgias
Contraindications and cautions
· Contraindicated with hypersensitivity to benzodiazepines, psychoses, acute narrow-angle glaucoma, shock, coma, acute alcoholic intoxication with depression of vital signs; pregnancy (risk of congenital malformations, neonatal withdrawal syndrome), labor and delivery ("floppy infant" syndrome), lactation (infants become lethargic and lose weight).
· Use cautiously with impaired liver or kidney function, debilitation.
Tablets—0.5, 1, 2 mg; orally disintegrating tablets—0.125, 0.25, 0.5, 1, 2 mg
Individualize dosage; increase dosage gradually to avoid adverse effects; drug is available only in oral dosage forms.
Seizure disorders: Initial dose should not exceed 1.5 mg/day PO divided into three doses; increase in increments of 0.5–1 mg PO every 3 days until seizures are adequately controlled or until side effects preclude further increases. Maximum recommended dosage is 20 mg/day.
Panic disorders: Initial dose 0.25 mg PO bid; gradually increase to a target dose of 1 mg/day.
PEDIATRIC PATIENTS > 10 YR OR 30 KG
Initially, 0.01–0.03 mg/kg/day PO; do not exceed 0.05 mg/kg/day PO, given in two or three doses. Increase dosage by not more than 0.25–0.5 mg every third day until a daily maintenance dose of 0.1–0.2 mg/kg has been reached, unless seizures are controlled by lower dosage or side effects preclude increases. Whenever possible, divide daily dose into three equal doses, or give largest dose hs.
Metabolism: Hepatic; T1/2: 18–50 hr
Distribution: Crosses placenta; enters breast milk
· CNS: Transient, mild drowsiness initially; sedation, depression, lethargy, apathy, fatigue, light-headedness, disorientation, anger, hostility, episodes of mania and hypomania, restlessness, confusion, crying, delirium, headache, slurred speech, dysarthria, stupor, rigidity, tremor, dystonia, vertigo, euphoria, nervousness, difficulty in concentration, vivid dreams, psychomotor retardation, extrapyramidal symptoms; mild paradoxical excitatory reactions during first 2 weeks of treatment
· CV: Bradycardia, tachycardia, CV collapse, hypertension and hypotension, palpitations, edema
· Dermatologic: Urticaria, pruritus, rash, dermatitis
· EENT: Visual and auditory disturbances, diplopia, nystagmus, depressed hearing, nasal congestion
· GI: Constipation, diarrhea, dry mouth, salivation, nausea, anorexia, vomiting, difficulty in swallowing, gastric disorders, hepatic dysfunction, encoporesis
· GU: Incontinence, urinary retention, changes in libido, menstrual irregularities
· Hematologic: Elevations of blood enzymes—LDH, alkaline phosphatase, AST, ALT; blood dyscrasias: agranulocytosis, leukopenia
· Other: Hiccups, fever, diaphoresis, paresthesias, muscular disturbances, gynecomastia. Drug dependence with withdrawal syndrome when drug is discontinued; more common with abrupt discontinuation of higher dosage used for longer than 4 mo
· Increased CNS depression with alcohol
· Increased effect with cimetidine, disulfiram, omeprazole, hormonal contraceptives
· Decreased effect with theophylline
· Risk of increased digoxin levels and toxicity; monitor patient carefully
Name confusion has been reported between Klonopin (clonazepam) and clonidine; use caution.
· History: Hypersensitivity to benzodiazepines; psychoses; acute narrow-angle glaucoma; shock; coma; acute alcoholic intoxication; pregnancy; lactation; impaired liver or kidney function, debilitation.
· Physical: Skin color, lesions; T; orientation, reflexes, affect, ophthalmologic examination; P, BP; R, adventitious sounds; liver evaluation, abdominal examination, bowel sounds, normal output; CBC, liver and renal function tests.
· Monitor addiction-prone patients carefully because of their predisposition to habituation and drug dependence.
· Monitor liver function and blood counts periodically in patients on long-term therapy.
· WARNING: Taper dosage gradually after long-term therapy, especially in patients with epilepsy; substitute another antiepileptic.
· Monitor patient for therapeutic drug levels: 20–80 ng/mL.
· Arrange for patient to wear medical alert ID indicating the patient has epilepsy and is receiving drug therapy.
· Take drug exactly as prescribed; do not stop taking drug (long-term therapy) without consulting health care provider.
· Avoid alcohol, sleep-inducing, or OTC drugs.
· Avoid pregnancy; serious adverse effects can occur. Use of barrier contraceptives is advised while taking this drug.
· You may experience these side effects: Drowsiness, dizziness (may become less pronounced; avoid driving or engaging in other dangerous activities); GI upset (take drug with food); fatigue; dreams; crying; nervousness; depression, emotional changes; bed-wetting, urinary incontinence.
· Report severe dizziness, weakness, drowsiness that persists, rash or skin lesions, difficulty voiding, palpitations, swelling in the extremities.
Adverse effects in Italic are most common; those in Bold are life-threatening.