Antacids and Antiulcer Agents 263cardiac arrest due to histamine release. The
cimetidine has antiandrogenic action and
can cause gynaecomastia, loss of libido and
impotence, otherwise all other H 2 blockers
are devoid of these side effects.
Therapeutic Uses
H 2 blockers are used in the treatment of:
- Duodenal ulcer.
- Gastric ulcer.
- Zollinger-Ellison syndrome (ZES).
- Gastroesophageal reflux.
- NSAID’s induced ulcers.
- Prophylaxis of aspiration pneumonia.
CIMETIDINE
Low potency, short duration of action.
Oral bioavailability is 60% and 2/3 is
excreted unchanged in urine and bile.
Incidence of adverse effects is 5%.
Table 7.3.1: Classification of drugs used in peptic ulcer.
I. Drugs which reduce gastric acid secretion
i. H 2 -receptor antagonists
Cimetidine (CIMETIN) 200-400 mg TDS-QID, 400 mg HS, 200-400
mg/day IM/IV
Ranitidine (HISTAC) 150 mg BD/HS, 50-100 mg/day IM/IV
Famotidine (FACID) 40 mg HS, 20 mg BD
Roxatidine (ZORPEX) 75-150 mg HS
Also available Nizatidine, Loxatidine.
ii. Proton pump inhibitor
Omeprazole (OMIZAC) 20-60 mg OD
Pantoprazole (PANTOCID) 40 mg OD
Rabeprazole (VELOZ) 20 mg OD
Also available Esomeprazole, Lansoprazole
iii.Prostaglandin analogues
Misoprostol (CYTOTEC) 200 μg QID
Enprostil 35-140 μg/day
Also available Rioprostil, Arbaprostil, Trimoprostil.
II. Ulcer healing agents
Carbenoxolone sodium (GASTRIULCER) 100 mg TDS
III.Ulcer protective agents
Sucralfate (SUCRASE) 1 g one hr before each (3) meals and at bed time
IV.Antacids (Neutralize gastric acid)
Systemic antacids
Sodium bicarbonate 0.3-1.5 g TDS-QID
Nonsystemic antacids
Magnesium carbonate 0.5-2 g/day
Magnesium hydroxide (MILK OF MAGNESIA) 0.3-1 g/day
Magnesium trisilicate 0.5-1 g/day
Aluminium hydroxide gel (ALUDROX) 0.5-1 g/day
Magaldrate (STACID) 400-800 mg/day
Calcium carbonate 0.5-1 g/day