The first line of treatment of schizophrenia is usually antipsychotic drugs. These drugs help in the treatment of the ‘positive symptoms’ of schizophrenia, such as hearing voices, seeing things and having strange beliefs. However, these drugs often have serious side effects, such as weight gain, muscle stiffness, tiredness, apathy and lack of drive. Dribbling or drooling (hypersalivation) is another common side effect, which frequently occurs at night when asleep. This can be an embarrassing and stigmatising problem that can affect quality of life and cause people to stop their medication, which may result in relapse and going back into hospital. Dribbling and drooling can be difficult to treat; however, anticholinergic drugs can decrease production of saliva and dribbling. This review assessed the evidence for the benefit or harm of anticholinergic drugs used in treating hypersalivation caused by antipsychotic or neuroleptic medication. The review excluded the antipsychotic clozapine, as its role in causing hypersalivation has been the subject of another Cochrane review.
The search was carried out 15 November 2012 and resulted in identification of four potential studies, but none could be included. Three of these were excluded because they involved clozapine-related hypersalivation. The fourth study was excluded because it involved people with mood or other mental disorders and Chinese medicines. Dribbling or hypersalivation is an important problem that needs to be investigated via well-designed research and randomised trials. Until such time, psychiatrists and patients are likely to continue their treatment of hypersalivation on the basis of daily clinical judgement and personal experience rather than hard evidence. Treatment of hypersalivation caused by antipsychotics or neuroleptics other than clozapine does not seem to have received adequate research attention to help guide practice. The review authors conclude that using anticholinergics to treat dribbling or hypersalivation caused by antipsychotic drugs other than clozapine cannot be justified without further study.