Digestive System

The chapter discusses drug-induced changes in the digestive system. The oral mucosa manifests local or systemic disease and derangements produced by therapeutic agents. A significant proportion of therapy-related oral drug reactions appear to be lichenoid reactions, erythema multiforme, and bullous lesions similar to idiosyncratic or immune-mediated skin reactions. Inflammation of the oral cavity (stomatitis) may involve the buccal mucosa, the gingiva, the tongue, and the peridontal tissues. Stomatitis can be induced by systemic administration of high doses of therapeutic agents. Anticonvulsant drugs may also produce changes in the dentition of humans and experimental animals. Discoloration of the teeth and bone is a well-described adverse effect of tetracycline administration and it has also been reported in patients who were treated with the semisynthetic derivative, minocycline. Drug-induced overgrowth of the gingival tissues is a well-described phenomenon in both humans and laboratory animals, including dogs, cats, and rats. Sessile or pedunculated squamous papillomas and infiltrating squamous carcinomas are occasionally found in the oral cavity of most laboratory animals, including rodents, rabbits, and beagle dogs.