Safety issues relating to long‐term treatment with histamine H₂‐receptor antagonists

Abstract

H,-receptor antagonist therapy is associated with a low incidence of adverse reactions. Adverse events reported in clinical trials of ranitidine in daily doses of up to 1200 mg include headache, tiredness and mild gastrointestinal disturbances, but the incidence is similar to or less than that for placebo. High doses of cimetidine ( > 5 g/day) can cause reversible impotence or gynaecomastia. While ranitidine exhibits no clinically significant drug-drug interactions, cimetidine interacts with many drugs metabolized by cytochrome P450. In contrast to ranitidine and cimetidine, where safety data are available for up to 10 years of continuous therapy, experience with famotidine and nizatidine is limited. The safety of long-term H,receptor antagonist therapy needs to be considered in relation to the potential consequences of prolonged acid suppression, including the risk of proliferation of gastric flora and the risk of developing enterochromaffin-like cell hyperplasia, which could in turn, theoretically, lead to gastric malignancy. Such problems have not been observed in patients during long-term therapy at low or full doses of H,-receptor antagonists. Standard doses of currently available H,-receptor antagonists permit acid secretion in response to food and other stimuli, and this daily acid tide prevents persistent bacterial colonization.

Atividades antiúlcera e antioxidante do extrato de folhas de Syzygium jambos (L.) Alston (Myrtaceae)

“…No entanto, estes fármacos podem ocasionar reações adversas graves, como trombocitopenia (Zlabek & Anderson, 2002), nefrite intersticial aguda (Ra & Tobe, 2004), nefrotoxicidade e hepatotoxicidade (Fisher & Le Couteur, 2001), reações anafiláticas , ginecomastia e impotência (Sabesin, 1993).…”

Anaesthetic antacids: a review of its pharmacological properties and therapeutic efficacy

“…In addition, the most frequent adverse effect of magnesium containing antacids is diarrhoea, which is due to poor absorption of the relatively insoluble magnesium salts and subsequent osmotic effect in the bowel, and these antacids components have been combined to counteract each other weaknesses. 2 Oxethazaine containing antacids relieves the pain by producing numbing effect at considerably, lesser dose in patients with oesophagitis, gastritis, and peptic ulcer. 11 This combination produced rapid rise in PH, a significantly higher peak PH, a greater period of anacidity from the time of medication until the PH returned to the acid range.…”

The Safety of Drugs Used in Acid-related Disorders and Functional Gastrointestinal Disorders

“…They are generally well tolerated and have a low incidence of side effects, 52-54 with the most commonly ascribed being diarrhea, dizziness, and headache. The estimated incidence of drug-related side effects is 5% to 8%.…”