Clonazepam [ 1 tablet 11 cents] ADMINISTRATION ROUTES:
IV, IM, PO
ALTERNATIVE NAMES: Rivotril, Paxam
ICU INDICATIONS: 2. treatmentofseizures/statusepilepticus
PRESENTATION AND ADMINISTRATION:
Direct IV infection is the preferred route of administration. Immediately before use, mix the clonazepam with contents of the diluent ampoule. Concentration is 1mg/2ml. Administer at a rate not exceeding 0.5ml/min of prepared solution. Can be given by IV infusion by mixing 1 ampoule in at least 85ml of compatible IV fluid and infusing slowly over 3-4 hours.
Compatible with the following IV fluids; Normal saline glucose and sodium chloride 5% dextrose 10% dextrose
Efficacy by IM route has not been demonstrated. May be given by this route only in exceptional cases or if IV administration is not feasible. Immediately before use, mix the clonazepam solution thoroughly with contents of the diluent ampoule. Concentration is 1mg/2ml
Paxam 0.5mg tablets (peach), 2mg tablet (white) Rivotril drops 2.5mg/ml
For status epilepticus 1mg IV; total maximum dose 10mg
PO: 0.5mg 12hrly; slowly increasing to up to 2mg 6 hrly
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY: Dose as in normal renal function
DOSAGE IN PAEDIATRICS:
For status epilepticus dosage NOT dosed per kg: Neonate 0.25mg (if ventilated) Child 0.5mg
PO: 0.01mg/kg (max 0.5mg) 12 hourly; increasing slowly to a maximum of 0.05mg/kg (max 2mg) 6-12 hrly
CLINICAL PHARMACOLOGY: Clonazepam is a benzodiazepine. The precise mechanism by which clonazepam exerts its antiseizure effect is unknown, although it is believed to be related to its ability to enhance the activity of gamma aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Clonazepam is rapidly and completely absorbed after oral administration. The absolute bioavailability of clonazepam is about 90%. Maximum plasma concentrations of clonazepam are reached within 1-4 hours after oral administration.
CONTRAINDICATIONS: 2. hypersensitivity to benzodiazepines
Withdrawal symptoms of the barbiturate type have occurred after the discontinuation of benzodiazepines including clonazepam
Worsening of Seizures When used in patients in whom several different types of seizure disorders coexist, clonazepam may increase the incidence or precipitate the onset of generalized tonic- clonic seizures (grand mal). This may require the addition of appropriate anticonvulsants or an increase in their dosages. Hypersalivation Clonazepam may produce an increase in salivation. This should be considered before giving the drug to patients who have difficulty handling secretions.
No tests in addition to routine ICU tests are indicated
Drug/Laboratory Test Interactions:
IMPORTANT DRUG INTERACTIONS FOR THE ICU The CNS-depressant action of the benzodiazepine class of drugs may be potentiated by alcohol, narcotics, barbiturates, nonbarbiturate hypnotics, antianxiety agents, the phenothiazines, thioxanthene and butyrophenone classes of antipsychotic agents, monoamine oxidase inhibitors and the tricyclic antidepressants, and by other anticonvulsant drugs.
Abnormal eye movements, aphonia, choreiform movements, coma, diplopia, dysarthria, dysdiadochokinesis, ‘glassy-eyed’ appearance, headache, hypotonia, nystagmus, respiratory depression, slurred speech, tremor, vertigo.
Confusion, depression, amnesia, hallucinations, hysteria, increased libido, insomnia, psychosis, suicidal attempt (the behavior effects are more likely to occur in patients with a history of psychiatric disturbances). The following paradoxical reactions have been observed: Excitability, irritability, aggressive behavior, agitation, nervousness, hostility, anxiety, sleep disturbances, nightmares and vivid dreams.
Chest congestion, rhinorrhea, shortness of breath, hypersecretion in upper respiratory passages. Cardiovascular: Palpitations.
Hair loss, hirsutism, skin rash, ankle and facial edema.
Anorexia, coated tongue, constipation, diarrhea, dry mouth, encopresis, gastritis, increased appetite, nausea, sore gums. Genitourinary: Dysuria, enuresis, nocturia, urinary retention.
Muscle weakness, pains.
Dehydration, general deterioration, fever, lymphadenopathy, weight loss or gain.
Anemia, leukopenia, thrombocytopenia, eosinophilia.
Hepatomegaly, transient elevations of serum transaminases and alkaline phosphatase.