Comparison of buccal and oral prochlorperazine in the treatment of dizziness associated with nausea and/or vomiting

The dizziness inherent in vertiginous disorders is often accompanied by nau sea and/or vomiting. While prochlorperazine is effective in relieving nause a and vomiting, its low bioavailability following first pass metabolism in the liver and metabolism in the intestinal wall, compounded by the likeliho od of regurgitation in the nauseous patient, may limit the therapeutic valu e of the oral preparation. A buccal preparation achieves higher plasma conc entrations by direct absorption into the systemic circulation. In this rand omised, double-blind, double-dummy trial in patients with vestibular disord ers, in keeping with previous pharmacokinetic studies, buccal prochlorperaz ine achieved a significantly faster onset of effect compared with oral proc hlorperazine (p = 0.04), and was significantly better in reducing the frequ ency of nausea (p = 0.02) and severity of vomiting (p = 0.05) at 24-36 hour s. The frequency of vomiting was also reduced by buccal prochlorperazine co mpared with oral prochlorperazine, but this difference was only of borderli ne significance (p = 0.07). Buccal prochlorperazine was well tolerated and well rated by both patients and investigators, having Mo more adverse effec ts an the buccal mucosa than placebo and causing less drowsiness and sedati on compared with the oral preparation. No advantages were reported for the oral preparation over buccal prochlorperazine. Buccal prochlorperazine is t herefore safe and effective, and suitable for the treatment of dizziness as sociated with nausea and/or vomiting in patients suffering from vertiginous disorders.