Safety profile of long-term H2-antagonist therapy

Commonly used gastrointestinal drugs

This chapter reviews the spectrum and mechanisms of neurologic adverse effects of commonly used gastrointestinal drugs including antiemetics, promotility drugs, laxatives, antimotility drugs, and drugs for acid-related disorders. The commonly used gastrointestinal drugs as a group are considered safe and are widely used. A range of neurologic complications are reported following use of various gastrointestinal drugs. Acute neurotoxicities, including transient akathisias, oculogyric crisis, delirium, seizures, and strokes, can develop after use of certain gastrointestinal medications, while disabling and pervasive tardive syndromes are described following long-term and often unsupervised use of phenothiazines, metoclopramide, and other drugs. In rare instances, some of the antiemetics can precipitate life-threatening extrapyramidal reactions, neuroleptic malignant syndrome, or serotonin syndrome. In contrast, concerns about the cardiovascular toxicity of drugs such as cisapride and tegaserod have been grave enough to lead to their withdrawal from many world markets. Awareness and recognition of the neurotoxicity of gastrointestinal drugs is essential to help weigh the benefit of their use against possible adverse effects, even if uncommon. Furthermore, as far as possible, drugs such as metoclopramide and others that can lead to tardive dyskinesias should be used for as short time as possible, with close clinical monitoring and patient education.

The safety of drugs used in acid-related disorders and functional gastrointestinal disorders

Medicines are frequently used in the management of acid-related disorders and functional gastrointestinal disorders. With the exception of complicated peptic ulcer disease, these disorders are not associated with appreciable mortality. Drug treatments have consequently been held to the highest standards of safety. Some medicines have been withdrawn or restricted based on assessments and perceptions of risk. However, the risk of serious toxicity is low for most of the agents discussed in this article. Assessments are made of the safety and adverse-event profiles of certain drug classes and, where appropriate, individual medicines. For conditions with a low risk of mortality or serious morbidity, clinicians need to balance the risks of potential adverse events with the anticipated benefits of a successful outcome of specific drug treatment.

Economic impact of inappropriate histamine2-receptor antagonist use

Histamine2 (H2)-receptor antagonists are widely prescribed for a variety of acid-mediated gastrointestinal disorders. The objective of the present study was to quantify the frequency of inappropriate H2-receptor antagonist use and its economic impact in patients who were admitted to a critical care bed at our hospital and followed as outpatients for 1 year. Eighty-eight (72%) of 123 patients admitted to the coronary care unit (CCU) or the intensive care unit over a 14-day period received H2-receptor antagonists. Forty-five (51%) of the 88 patients did not have a documented indication for H2-receptor antagonist therapy. Most of the patients without indications were admitted to the CCU for cardiac diagnoses. Thirty-eight patients (43%) were discharged on oral H2-receptor antagonist therapy. Twenty (53%) of the 38 patients had no documented indication for therapy; 17 of these patients continued H2-receptor antagonist therapy for 1 year, whereas the remaining 3 patients received therapy for 1, 2, and 3 months, respectively. The cost of therapy for the 45 patients receiving inappropriate therapy during hospitalization was $5,084.31. Outpatients costs for the 20 patients remaining on inappropriate therapy was $8,619.75. The total cost of inappropriate therapy was $13,704.06. If data collected during this 2-week period were extrapolated to 1 year, the projected annual cost of inappropriate therapy would be $356,305.56. The economic impact of inappropriate H2-receptor antagonist therapy at our institution is great. Programs designed to reduce such inappropriate use must be implemented and evaluated for their ability to decrease the associated costs.