Efficacy and economic evaluation of pilocarpine in treating radiation-induced xerostomia

Xerostomia, resulting from therapeutic irradiation of the head and neck, can be debilitating and destructively impact the patient's quality of life. The first priority of treatment of radiation-induced xerostomia should be to preserve oral and dental health. Therapeutic doses of fluoride and meticulous dental hygiene are the treatments of choice for this purpose. Measures taken to prevent superinfection with cariogenic bacteria and fungi are also important. In addition to minimising damage to the dentition, it is important to provide palliative therapy to help the patient live a more normal life. Salivary substitutes help some patients but muscarinic, cholinergic sialogogues provide a more physiological replacement in those patients who have measurable residual salivary function. An oral formulation of pilocarpine hydrochloride is approved to treat radiation-induced xerostomia. In such cases, it has been shown to effectively stimulate salivary flow and relieve subjective symptoms associated with oral dryness. Administration of this drug is associated with predictable, but generally tolerable, adverse effects. Similar drugs, approved for other indications, have been shown to produce comparable results. These drugs are generally less expensive than the oral formulation of pilocarpine. As treatment of irradiation-induced xerostomia with muscarinic, cholinergic sialogogues is palliative, not curative, administration of these drugs should be individualised and guided by the patient's willingness to balance symptomatic efficacy with adverse effects and the expense of treatment.