Sedation. Clonazipam is a benzodiazepam, which usually has a very sedating effect. Overdose can include drowsiness, confusion, in coordination, and even coma. If combined with alcohol and some other drugs, the symptoms can be even more extreme. Treatment includes pumping the stomach and certain medications.
Klonopin (clonazepam) OD. Please refer to my answer "benzodiazepine overdose".