Sir: Hypersalivation associated with clozapine can be a distressing and difficult to manage side-effect (Cree et al, Psychiatric Bulletin, 2001, 25, 114-116). In recent months we have used hyoscine hydrobromide patches in a group of patients with disabling hypersalivation. We had used the patches to treat severe hypersalivation in a patient on depot medication on the advice of a colleague working in ear, nose and throat medicine. This patient had gained some relief from atropine drops but could not tolerate the bitter taste. He had not been helped by oral anticholinergic medication and it was to our surprise that he responded dramatically to the use of the patches.

We have since used the patches on four patients with severe disabling, clozapine-induced hypersalivation (dosage 500-800 mg/day). These patients had obvious drooling that often required a change of clothing with marked soaking of their pillows each morning. A dramatic improvement has been noted in each case.

The patches are well tolerated. They are sited on bare skin behind the ear and release 1 mg of hyoscine over a 72-hour period. They have brought about a sustained improvement in our patients' quality of life. This small sample suggests that hyoscine patches are effective especially in those patients suffering severe hypersalivation. It is interesting to note that the patches proved effective in patients who had not responded to oral treatments, including oral hyoscine.