Drug hypersensitivity to tolperisone – case report

Abstract

Introduction. Drug hypersensitivity, now a worldwide health problem, undoubtedly has gained significance in the last years due to the increasing number of patients categorized as drug allergic. We underline unpredictable adverse reactions (type B reactions) after administration of tolperisone. The severity of anaphylaxis ranged from urticarial reactions to shock with arterial hypotension that was treated at the Emergency Room. Aim. In clinical practice, there is an increase in the number of cases with a positive history of anaphylactic events due to administration of tolperisone. The purpose was to raise awareness among medical practitioners and take in consideration these frequent side effects when prescribing tolperisone. Materials and method. Our case report involved a middle aged woman who took tolperisone for chronic muscular pain. Reactions occurred within 15 to 20 minutes after oral intake of this drug frequently prescribed in our country. Discussion. Consulting medical articles and literature, the reporting of adverse reactions to tolperisone are scarce, possibly due to lack of commercialization in many countries. At the Emergency Department of the Emergency County Hospital of Târgu-Mureş we found several (almost 2-3 per year) presentations with suspicion of severe allergic reaction due to tolperisone, without further investigations. Conclusions. Our research and the frequency of anaphylactic occurrences suggest that anaphylaxis to tolperisone is not uncommon, varying from urticaria and angioedema to more major reactions such as dyspnea and hypotension. Often, severe allergic reactions are likely to appear when tolperison is taken in combination with nonsteroidal anti-inflammatory drugs (NSAIDs). In Romania, tolperisone remains a popular myorelaxant agent often bought without medical prescription. The mechanism of these allergic-like reactions remains unclear.