Outbreak of hypoglycaemia: sexual enhancement products containing oral hypoglycaemic agent

WT Poon, YH Lam, Hencher HC Lee, CK Ching, WT Chan, SS Chan, CK Lai, ML Tse, Albert YW Chan, Tony WL Mak
Hospital Authority Toxicology Reference Laboratory, Princess Margaret Hospital, Laichikok, Hong Kong

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.

Hong Kong Med J 2009;15:196-200

Key words: Drug contamination; Erectile dysfunction; Hypoglycemia; Nonprescription drugs