Klonopin or Clonazepam as it is otherwise known is a benzodiazepine in the same class as alprazolam and is used to treat panic disorders and seizures, amongst many other psychological conditions. In a substantial retrospective study on 25 years of clinical usage of Klonopin for the treatment of tinnitus, it was found that of 3,357 patients treated, 32% reported improvements in tinnitus. Patients were treated daily with either 0.5 or 1.0mg tablets of Klonopin.

The drug was most effective for vertigo patients where it completely or substantially controlled dizziness in 77% of patients. 16% reported adverse side-effects including: mild drowsiness, nightmares, depression, and lowering of libido [[i]]. 

There is also evidence that clonazepam is effective in the treatment of pulsatile tinnitus [[ii]].  There still remains the need for rigorous clinical trials into the effectiveness of the drug when compared with placebo.