clonazepam

see also benzodiazepines, anticonvulsants

• Rivotril
• Unusually potent at antag. effects of pentylenetetrazol but almost without action in ECT-induced seizures thus has anticonvulsant activity in wide range of seizure type with notable exception of generalised tonic-clonic seizures & thus useful in absences & myoclonic seizures in children but tolerance to these actions often develop after 1-6mths when no dose of clonazepam will be of use!!;
• Plasma Rx range not helpful; Optimal dose hard to predict;
• To avoid sedation/irritability, keep initial dose low (eg. 0.25mg bd) & increased wkly.
• Chronic use → behav. effects, drowsiness, lethargy, hypotonia;
• High-dose as in IV 0.25-1mg use (as with IV diazepam) → reduce sustained high-frequency firing of neurons similar to that seen with phenytoin, carbamazepine & sodium valproate (Epilim);
• After IV dose → redistributed (→ muscle → fat) terminating action;

• useful in acute Mx of absences & myoclonic seizures in children
• Draw up all of 1ml ampoule (ie. 1mg) of clonazepam into 2ml syringe and dilute with 1ml diluent thus making final concentration of 0.5mg/ml.
• ventilated neonate: 0.25mg IV
• child:
  • Give 0.25mg slow IV over 1min, and repeat in 0.125mg doses every 2-3min as needed up to 1mg over 5-10min.
• adult 1.0mg IV