Histamine H2 receptor antagonist used in the treatment of gastric and duodenal ulcers, gastroesophageal reflux and hypersecretory states.
3 cases described in obstetric patients.
Differentiate from other side-effects: headaches, tiredness, dizziness, mild gastrointestinal disturbance.
General: anaphylactic shock
Respiratory: dyspnea, bronchospasm, laryngeal edema.
Cutaneous: pruritus, urticaria, edema of the face, tongue, arms, maculopapular rash, toxic epidermal necrolysis, cutaneous delayed reactions (papular eruptions).
Digestive: acute cholestatic hepatitis with rash and hypereosinophilia (one case).
Skin prick-tests: 10 mg/ ml positive with ranitidine, negative with famotidine, nizatidine, nitrofurantoin.
Intradermal skin tests: one case positive 1/1000.
No specific IgE found.
IgE-mediated hypersensitivity (positive skin tests, positive oral challenge).
Direct histamine release.
Cross-reactivity with other H2 receptor antagonists is exceptional (one case published)
Omeprazole can be used in obstetric patients to reduce gastric acid production.