Hydroquinine hydrobromide and hypoglycaemia Introduction

Introduction Hydroquinine hydrobromide (Inhibin) has been approved for marketing in the Netherlands for the treatment of nocturnal cramps when treatment with drugs is considered necessary. It is available in the Netherlands since March 1990 as an over-the-counter drug with a dose of 200 mg with the evening meal and a further 100 mg at bedtime for 14 days. According to the Summary of Product Characteristics (SmPC), hydroquinine hydrobromide can be re-administered when nocturnal cramps return [1]. Traditionally, quinine and its derivatives such as hydroquinine have been used for the prevention of nocturnal cramps but there has been concern over their efficacy and potential for adverse drug reactions (ADRs), especially in the elderly. However, in a randomized, double-blind, placebocontrolled trial, conducted in the Netherlands, 300 mg hydroquinine hydrobromide was considered safe if used for a short period and significantly more effective than placebo in the prevention of frequent, ordinary muscle cramps [2]. The most frequently reported ADRs are nausea, dry mouth, vomiting, and tinnitus [1]. Although hypoglycaemia is not mentioned in the SmPC, Lareb received three spontaneous reports of lowered blood glucose levels associated with the use of hydroquinine.