ADMINISTRATION ROUTES:
IV, IM, PO
ALTERNATIVE NAMES:
Rivotril, Paxam
ICU INDICATIONS:
- Treatment of seizures / status epilepticus
PRESENTATION AND ADMINISTRATION:
IV:
Direct IV injection is the preferred route of administration. Immediately before use, mix clonazepam with contents of the diluent vial. Concentration is 1 mg/2 mL. Administer at a rate not exceeding 0.5 mL/min of prepared solution.
Can be given by IV infusion by mixing 1 vial in at least 85 mL 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
IM:
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 vial. Concentration is 1 mg/2 mL
PO:
Paxam 0.5mg tablets (peach), 2mg tablet (white) Rivotril drops 2.5 mg/mL
DOSAGE:
IV:
Status epilepticus:
1 mg repeated to total maximum dose 10 mg
PO:
0.5 mg BD, slowly increased up to 2 mg QID
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Dose as in normal renal function
DOSAGE IN PAEDIATRICS:
IV: For status epilepticus is NOT dosed per kg
Neonate 0.25 mg (if ventilated) Child 0.5 mg
PO:
0.01 mg/kg (max 0.5 mg) BD, slowly increased to maximum 0.05 mg/kg (max 2 mg) 6-12hrly
CLINICAL PHARMACOLOGY:
Clonazepam is a benzodiazepine. The precise mechanism by which clonazepam exerts its anti-seizure 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:
- Hypersensitivity to benzodiazepines
WARNINGS:
Withdrawal Symptoms:
Withdrawal symptoms of the barbiturate type have occurred after the discontinuation of benzodiazepines including clonazepam
PRECAUTIONS:
General:
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 generalised 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.
Laboratory Tests:
No tests in addition to routine ICU tests are indicated
Drug/Laboratory Test Interactions:
None noted
IMPORTANT DRUG INTERACTIONS IN 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.
ADVERSE REACTIONS:
Neurological:
Abnormal eye movements, aphonia, choreiform movements, coma, diplopia, dysarthria, dysdiadochokinesis, 'glassy-eyed' appearance, headache, hypotonia, nystagmus, respiratory depression, slurred speech, tremor, vertigo
Psychiatric:
Confusion, depression, amnesia, hallucinations, hysteria, increased libido, insomnia, psychosis, suicidal attempt (the behaviour effects are more likely to occur in patients with a history of psychiatric disturbances). The following paradoxical reactions have been observed: Excitability, irritability, aggressive behaviour, agitation, nervousness, hostility, anxiety, sleep disturbances, nightmares and vivid dreams
Respiratory:
Chest congestion, rhinorrhea, shortness of breath, hypersecretion in upper respiratory passages
Cardiovascular:
Palpitations
Dermatologic:
Hair loss, hirsutism, skin rash, ankle and facial oedema
Gastrointestinal:
Anorexia, coated tongue, constipation, diarrhoea, dry mouth, encopresis, gastritis, increased appetite, nausea, sore gums
Genitourinary:
Dysuria, enuresis, nocturia, urinary retention
Musculoskeletal:
Muscle weakness, pains
Miscellaneous:
Dehydration, general deterioration, fever, lymphadenopathy, weight loss or gain
Haematological:
Anaemia, leukopaenia, thrombocytopaenia, eosinophilia
Hepatic:
Hepatomegaly, transient elevations of serum transaminases and alkaline phosphatase