A randomized, controlled comparison of the efficacy and tolerability of low and high doses of haloperidol in the treatment of first-episode psychosis.

While haloperidol is still widely used in the treatment of psychoses, the optimal daily dose remains a topic of controversy, particularly in first-episode psychosis. Previous studies have suggested that doses as low as 2 mg/d may be effective, whereas others have indicated superiority for higher over lower doses. This double-blinded, randomized controlled study compared the efficacy and tolerability of 2 vs. 8 mg/d of haloperidol over 6 wk in 40 subjects with first-episode psychosis. Both treatments were equally effective in reducing the PANSS Total and subscale scores. The low dose of haloperidol was better tolerated, with fewer extrapyramidal side-effects, less frequent use of anticholinergic medication and smaller elevations in prolactin levels. Using a low dose of haloperidol is at least as effective as, and better tolerated than a high dose of haloperidol in the treatment of first-episode psychosis.