Objectives: To describe a cluster of Hong Kong subjects with hypoglycaemia, after they had taken various non-prescription sildenafil products containing glibenclamide.
Design: Retrospective study.
Setting: A tertiary referral centre for clinical toxicology analysis in Hong Kong.
Patients: All men referred to the laboratory for investigation of suspected drug-induced hypoglycaemia from December 2007 to September 2008.
Main outcome measures: The characteristics of these patients, including their clinical presentations, outcomes, drug history, urine toxicology analysis results, and in some instances, analysis results of unused products.
Results: A total of 144 male patients were referred for suspected drug-induced hypoglycaemia. Sildenafil and glibenclamide, or their metabolites, were detected in the urine specimens of 68 (47%) patients, none of whom had been prescribed either drug by a registered medical practitioner. Among these subjects, 24 (35%) denied any use of sexual enhancement products despite repeated questioning. Eight patients had repeated exposure resulting in re-admission. The sources of these sexual enhancement products included pharmacies in Mainland China, friends, local pharmacies, peddlers, or were unknown. Three patients died, one remains in a vegetative state and one suffered cognitive impairment; the remaining 63 recovered fully. Twenty-five unused sexual enhancement products of seven different kinds were recovered for analysis. The median (range) of sildenafil and glibenclamide per unit dose was 64 (0.05-198) mg and 70 (0-158) mg, respectively.
Conclusion: These illegal products pose a severe and continued threat to society and therefore deserve widespread vigilance, so that such products can be eradicated at their source.