Parasympathomimetic drugs for the treatment of salivary gland dysfunction due to radiotherapy

There is limited evidence to support the use of pilocarpine hydrochloride in the treatment of radiation-induced salivary gland dysfunction. Salivary gland damage is a frequent and important complication of radiotherapy to the head and neck area; it causes dryness of the mouth with resultant problems with eating, talking, and local infection. The parasympathomimetic group of drugs have been used to treat radiotherapy induced salivary gland damage. Three studies were identified which involved a total of 289 patients, and they all used the drug pilocarpine. The review found that 42 to 51% of patients responded to pilocarpine, although the response did not occur in some for up to 12 weeks. The pilocarpine was more effective than a placebo treatment, and at least as effective as an artificial saliva. Side effects were common with pilocarpine (e.g. sweating, headache, passing urine frequently, flushing), but were reported to be usually mild, although some (6 to 15%) patients had to stop taking the pilocarpine due to the side effects. The findings of this review are limited by the small number of good quality trials that have been performed in this area of medicine.