A pilot study of the effects of flumazenil on symptoms persisting after benzodiazepine withdrawal.

The potential of the benzodiazepine antagonist flumazenil (Ro 15-1788) to lessen persisting benzodiazepine withdrawal symptoms was demonstrated in 11 patients who had been drug free for between 1 month and 5 years. Doses ranging from 0.2 to 2.0 mg divided into three intravenous injections over a few hours relieved long-standing symptoms to varying extents. These included clouded thinking, tiredness, muscular symptoms such as neck tension, cramps and shaking and the characteristic perceptual symptoms of benzodiazepine withdrawal, namely, pins and needles, burning skin, pain and subjective sensations of bodily distortion. Mood disorder, when present, also improved but the reduction in anxiety and depression may have reflected relief of physical symptoms. The onset of maximum response was sometimes delayed by as much as a day but was usually prompt. Side effects were reported to be either absent or typically described as lightheadedness or dizziness, lasted only a few minutes and were usually well tolerated. The benefits last between a few hours and several days despite flumazenil's otherwise short duration of action. However, symptoms did return to varying degrees in most cases, suggesting the need for repeated doses.