Drug-induced xerostomia is the sensation of dry mouth due to decreased or absent salivary gland flow or production resulting from a medication. It occurs when a drug prevents the central nervous system (CNS) from making acetylcholine (ACh) or occupies the adrenergic / muscarinic receptors responsible for salivary secretion. While there are numerous causes of xerostomia, medication use is the most commonly reported cause. It is more frequent in individuals older than 65 years of age, especially those on 2 or more medications.

Drug-induced xerostomia is associated with over 500 drugs. Classes of drugs more commonly implicated include angiotensin converting enzyme (ACE) inhibitors, alpha-adrenergic agonists, antibiotics, anticholinergics, antidepressants, antidiarrheals, antihistamines, antihypertensives, antipsychotics, anxiolytics, beta blockers, bronchodilators, cannabinoids, chemotherapeutics, decongestants, diuretics, muscle relaxants, opioids, and proton pump inhibitors, among others. Alcohol, caffeine, tobacco, and recreational drugs (eg, marijuana, methamphetamine) are also associated.

Symptoms of xerostomia may include dysgeusia, oral burning and soreness, and secondary anorexia. Due to insufficient oral mucosal lubrication in the pharynx, patients may sometimes experience impaired speech and coughing. If drug-induced xerostomia is not treated, complications include aphthous stomatitis, caries, dysphagia, gingivitis, halitosis, weight loss, mucositis, periodontitis, and oral candidiasis. Patients with chronic, untreated drug-induced xerostomia are also at increased risk of anxiety and depression as a complication.