Adjunctive antianxiety agents in the management of chronic pain.

We examined the relative clinical efficacy of three commonly used antianxiety medications and a placebo as adjuncts to analgesic treatment of chronic cancer and arthritic pain. Nine patients with chronic pain, including six with malignancy and three with rheumatic diseases, were each exposed to three treatment phases with antianxiety drugs (hydroxyzine, prochlorperazine, and chlordiazepoxide) and one placebo phase in a double-blind, counter-balanced design. Each phase lasted 2 weeks, with analgesic medication given throughout. Pre- and post-phase measures of anxiety, depression, and hostility were taken, together with daily reports by the patients on pain, mood, and medication intake. None of the antianxiety drugs were significantly more effective than the placebo in reducing pain levels, daily medication usage or hostility. Chlordiazepoxide significantly reduced anxiety and depression compared with the placebo, but also produced the most side effects (e.g., drowsiness). The preliminary findings failed to support the efficacy of the three antianxiety medications as analgesic adjuncts.