Do cigarettes diminish the effects of clonazepam?

Yes: Nicotine in cigarettes is a stimulant that will increase heart rate, blood pressure and anxiety. Nicotine counters the calming effects of clonazepam. Ask your doctor for ways to help you quit smoking. Best wishes.

It depends: Stimulants like nicotine can help some relax. Others can be agitated by nicotine. Dose can make a difference.

Probably so: Clonazepam is metabolized by a different CYP enzymes than nicotine, thus the blood levels are not effected. However, the calming effect of clonazepam is caused by activating GABA receptors in the brain. Nicotine binds to these same receptors but results in lower intensity of activation. So the net is less effect from the clonazepam. Nicotine also causes neural excitation, further countering it