It is indicated for the treatment of panic disorder, with or without agoraphobia. Panic disorder is characterized by the occurrence of unexpected panic attacks and associated concern about having additional attacks, worry about the implications or consequences of the attacks.
It is also indicated alone or as an adjunct in the treatment of the Lennox-Gastaut Syndrome (petit mal variant), akinetic and myoclonic seizures. It may be indicated in patients with absence seizures (petit mal) who have failed to respond to succinimides.
The effectiveness of Clonazepam in long-term use, that is, for more than 9 weeks, has not been systematically studied in controlled clinical trials. The physician who elects to use Clonazepam for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient.
Adjunct anti-epileptic drugs, Benzodiazepine hypnotics
Clonazepam reduces the nerve transmission in the motor cortex which suppresses the spike and wave discharge in absence seizures. Its mechanism is believed to be related to its ability to enhance the activity of GABA. Clinically, it improves focal epilepsy and generalised seizures.
- Adults: The initial dose for adults with seizure disorders should not exceed 1.5 mg/day divided into three doses. Dosage may be increased in increments of 0.5 to 1 mg every 3 days until seizures are adequately controlled or until side effects preclude any further increase. Maintenance dosage must be individualized for each patient depending upon response. Maximum recommended daily dose is 20 mg.
- The initial dose for adults with panic disorder is 0.25 mg given in two divided dose. An increase to the target dose for most patients of 1 mg/day may be made after 3 days.
- Pediatric Patients: In order to minimize drowsiness, the initial dose for infants and children (up to 10 years of age or 30 kg of body weight) should be between 0.01 and 0.03 mg/kg/day but not to exceed 0.05 mg/kg/day given in two or three divided doses.
- Infants and children: half of a vial (0.5 mg) by slow IV injection or by IV infusion.
- Adults: 1 vial (1 mg) by slow IV injection or by IV infusion. This dose can be repeated as required (1-4 mg are usually sufficient to reverse the status). In adults, the rate of injection must not exceed 0.25 - 0.5 mg per minute (0.5-1.0 ml of the prepared solution) and a total dose of 10 mg should not be exceeded.
Clonazepam does not appear to alter the pharmacokinetics of phenytoin, carbamazepine or phenobarbital. The effect of Clonazepam on the metabolism of other drugs has not been investigated.
It should not be used in patients with a history of hypersensitivity to benzodiazepines, nor in patients with clinical or biochemical evidence of significant liver disease. It may be used in patients with open angle glaucoma who are receiving appropriate therapy but is contraindicated in acute narrow angle glaucoma.
The most frequently occurring side effects of Clonazepam are referable to CNS depression. Experience in treatment of seizures has shown that drowsiness has occurred in approximately 50% of patients and ataxia in approximately 30%. In some cases, these may diminish with time; behavior problems have been noted in approximately 25% of patients. Abnormal eye movements, aphonia, coma, tremor, vertigo, confusion, depression, amnesia, hallucinations, hysteria, increased libido, insomnia, psychosis & palpitations may also occur.
Clonazepam should be used in pregnancy only if the potential benefits outweigh the potential risk to the fetus and it is recommended that women receiving Clonazepam should not breast feed.
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. This may require the addition of appropriate anticonvulsants or an increase in their dosages. The concomitant use of valproic acid and Clonazepam may produce absence status.
The cardinal manifestations of overdosage are drowsiness and confusion, reduced reflexes and coma. There are minimal effects on respiration, pulse and blood pressure, unless the overdosage is extreme.
Slow intravenous injection: The contents of the vial must be diluted with 1 ml of water for injection prior to administration so as to avoid local irritation of the veins. The injection solution should be prepared immediately before use. IV injection should be administered slowly with continuous monitoring of EEG, respiration and blood pressure.
Intravenous infusion: Clonazepam (the vial) can be diluted for infusion in a ratio of 1 vial (1 mg) to at least 85 ml diluting media. The diluting media can be any of the following: sodium chloride 0.9%; sodium chloride 0.45% + glucose 2.5%; glucose 5% or glucose 10%. These mixtures are stable for 24 hours at room temperature. Infusion bags other than PVC should be used for infusing Clonazepam. If PVC infusion bags are used then the mixture should be infused immediately or within 4 hours. The infusion time should not exceed 8 hours. Do not prepare Clonazepam infusions using sodium bicarbonate solution, as precipitation of the solution may occur.
Intramuscular injection: The IM route should be used only in exceptional cases or if IV administration is not feasible.
Keep in a dry place away from light and heat. Keep out of the reach of children.