Prescribing this drug to addicts may give rise to iatrogenic drug misuse

EDITOR—I was interested to read Jones and Sullivan's report on dependence on zopiclone1 because Ruben and I had earlier reported six cases of misuse of zopiclone among polydrug users in Liverpool.2 The average daily dose of zopiclone was 105 mg (range 90-380 mg) and the average duration of use 10 months (6-24 months). All the patients initially used the drug for sleeping but later developed tolerance to its sedative property. Common daytime side effects reported were drowsiness, dry mouth, nausea, ataxia, and psychomotor slowing. The main withdrawal symptoms reported were rebound insomnia, a feeling of being edgy, and a strong craving 6-8 hours after the last dose. This led to self treatment to obtain relief from the withdrawal symptoms. None of the …