SUPPRESSION OF HERPES-SIMPLEX VIRUS-INFECTIONS WITH ORAL LITHIUM-CARBONATE - A POSSIBLE ANTIVIRAL ACTIVITY

In vitro studies have shown an inhibitory effect of lithium salts on h erpes simplex virus (HSV) replication by mechanisms that interfere wit h viral DNA synthesis. Moreover, clinical studies have shown that oral . lithium carbonate and topical lithium succinate can suppress genital HSV infections in humans. We conducted a randomized, double-blind, pl acebo-controlled trial of oral lithium carbonate in 11 healthy subject s age 28-65 years (mean +/- SD age 38 +/- 11 years) who had at least f our recurrent HSV infections in the year preceding the study. Six pati ents completed at least 5 months of lithium therapy at a mean (+/- SD) average daily lithium dose of 437 +/- 185 mg (range, 150-900 mg) and an average serum lithium level of 0.56 +/- 0.20 mmol/L. Overall, lithi um treatment resulted in a consistent reduction in the mean number of episodes/month, the average duration of each episode, the total number of infection days/month, and the maximum symptom severity. In contras t, treatment with placebo resulted in an increase in three out of the four severity measures. Although the comparisons between the treatment groups did not achieve statistical significance due to the limited sa mple size, there was a clear ''trend'' for a reduction in the total mo nthly duration of all HSV infections with lithium (p=0.08). Lithium tr eatment was well tolerated and produced no deleterious effects on rena l or thyroid function. These observations lend support to prior observ ations of an antiviral activity of lithium, and suggest the possibilit y that oral lithium may represent a safe prophylactic agent in patient s with recurrent HSV infections.