Helicobacter pylori infection and drugs malabsorption

Abstract

Drug absorption represents an important factor affecting the efficacy of oral drug treatment. Gastric secretion and motility seem to be critical for drug absorption. A causal relationship between impaired absorption of orally administered drugs and Helicobacter pylori (H. pylori) infection has been proposed. Associations have been reported between poor bioavailability of l-thyroxine and l-dopa and H. pylori infection. According to the Maastricht Florence Consensus Report on the management of H. pylori infection, H. pylori treatment improves the bioavailability of both these drugs, whereas the direct clinical benefits to patients still await to be established. Less strong seems the association between H. pylori infection and other drugs malabsorption, such as delavirdine and ketoconazole. The exact mechanisms forming the basis of the relationship between H. pylori infection and impaired drugs absorption and/or bioavailability are not fully elucidated. H. pylori infection may trigger a chronic inflammation of the gastric mucosa, and impaired gastric acid secretion often follows. The reduction of acid secretion closely relates with the wideness and the severity of the damage and may affect drug absorption. This minireview focuses on the evidence of H. pylori infection associated with impaired drug absorption.

Keywords: Drug malabsorption; Helicobacter pylori gastritis; Gastric hypoacidity; Thyroxine treatment; Thyroxine malabsorption; Human immunodeficiency virus; Delavirdine; L-dopa; Parkinson’s disease; Ketaconazole

Core tip: Drug absorption is a critical factor affecting the efficacy of orally administered therapies. A causal relationship between impaired absorption of orally administered drugs and Helicobacter pylori (H. pylori) infection has been proposed. Previous studies have observed that H. pylori infection and poor bioavailability of l-dopa and l-thyroxine are associated. Less strong seems the association between H. pylori infection and delavirdine and ketoconazole malabsorption. The absorption of oral drugs may potentially be influenced by gastric pH. When a treatment with an oral drug fails, this may be due to a H. pylori-related gastritis and its associated gastric hypochlorhydria, which may partially or totally be reversible.