Clonazepam

Clonazepam is a benzodiazepine drug having anxiolytic, anticonvulsant, muscle relaxant, and hypnotic properties. It is marketed by Roche under the trade name Klonopin (or Klonapin) in the United States and Rivotril in Argentina, Australia, Brazil, Canada, Costa Rica, India, Mexico and Europe. Other names such as Ravotril, Rivatril, Rivotril, Clonex, Paxam, Petril or Kriadex are known throughout the rest of the world. Clonazepam has an unusually long elimination half-life of 18–50 hours, making it generally considered to be among the long-acting benzodiazepines. Clonazepam is a chlorinated derivative of nitrazepam and therefore a chloro-nitrobenzodiazepine.

Clonazepam has a slow onset with a peak four hours after ingestion. It has high effectiveness rate and low toxicity in overdose but, as most medications, it may have drawbacks due to adverse reactions including paradoxical effects and drowsiness. Other long-term effects of benzodiazepines include tolerance, benzodiazepine dependence, and benzodiazepine withdrawal syndrome, which occurs in a third of people treated with clonazepam for longer than four weeks. Clonazepam is classified as a high potency benzodiazepine.

The use of clonazepam in long term treatment is inhibited by its ability to induce tolerance to the anticonvulsant effects. However, in a study of patients with epilepsy, the medication could be withdrawn successfully in most patients. In some patients seizures control was reduced after withdrawal, but reintroduction of Clonazepam rapidly resulted in control of the epilepsy. No significant change in cognitive function, mood or behaviour was noted in the patients who discontinued CZP.

The benzodiazepine clorazepate may be an alternative to clonazepam due to a slow onset of tolerance and availability in slow-release formulation to counter fluctuations in blood levels. The pharmacological property of clonazepam as with other benzodiazepines is the enhancement of the neurotransmitter GABA via modulation of the GABA_A receptor.