H2 ANTAGONISTS - a patient's guide
TYPE/ BRAND NAME:
- Cimetidine: Apo-Cimetidine, Duomet, Tagamet
- Famotidine: Apo-Famotidine, Famox, Pepzan, Pepcidine
- Nizatidine: Axid
- Ranitidine: Zantac
USE: Histamine H2- receptor antagonist
H2- Antagonists are used for the treatment of stomach and duodenal ulcers, heartburn, and other related conditions which are a result of excess stomach acid production. They can also be used in post-op surgery to prevent stress ulcers in ill patients and in patients receiving NSAID (e.g. aspirin) therapy.
These medicines work by controlling the production of stomach acid via H2- receptor blockade, where they still allow the stomach to produce the amount of acid for digestion, but extra acid build-up that can cause problems (e.g. ulcers) does not occur.
Gastric cancer (these drugs may mask early symptoms of more serious disease)
Pregnancy and breastfeeding (discuss with doctor)
Occasional: headache, dizziness, diarrhoea, altered liver function tests
Rarely: acute stomach pain, slow heartbeat, confusion, depression, skin rash, blood disorders
Cimetidine is a potent enzyme inhibitor therefore should be avoided with warfarin, phenytoin, theophylline, anti-arrhythmics, antidepressants, opoid analgesics, and many other drugs.
Always check and discuss potential interactions with your doctor.
Famotidine, nizatidine and ranitidine do not have these interactions.
- Follow instructions carefully on the label of this medicine or as directed by your doctor.
- Used for the treatment of stomach ulcers therefore it should be taken regularly.
- Avoid smoking and certain foods (talk to your pharmacist).
- Food: Take with food if this medicine upsets your stomach
- Alcohol: May aggravate stomach ulcers so best avoided
- Contact your doctor or seek medical help if side effects are severe or ongoing.
- These medications should not be taken long term without an accurate diagnosis of what is wrong - this may include endoscopy to look at the oesophagus, stomach and duodenum.