Pirenzepine Cimetidine

Gastrointestinal Cimetidine, famotidine, mesalazine, metiamide, metoclopramide, omeprazole, pirenzepine, ranitidine... 

Pirenzepine blocks cholinergic receptor. Cimetidine blocks H2 histamine receptor. Misoprostol stimulates prostaglandin receptor. 

Riedel R, Bohnenkamp W, Eltze M, Heintze K, Prinz W, Kromer W. Comparison of the gastric antisecretory and antiulcer potencies of telenzepine, pirenzepine, ranitidine and cimetidine in the rat. Digestion, 1988, 40(1), 25-32. 

Anticholinergics such as atropine are now believed to act on both M, and M2 cholinergic receptors, accounting for both its antisecretory (Mi) and other anticholinergic properties such as ocular, bladder, and salivary side effects (M2). As mentioned earlier, the benzodiazepine compound pirenzepine is highly MI specific. At doses that inhibit HC1 secretion these side effects are not a significant problem. Although not necessarily more effective than cimetidine (see later), it is effective in otherwise treatment-resistant peptic... 

Gut Atropine, methscopolamine, and propantheline were used in acid-peptic disease to reduce acid secretion, but they are not as effective as H,-blockers such as cimetidine, and they cause far more frequent and severe adverse effects. Pirenzepine is an M -selective muscarinic blocker (available in Europe but not tbe USA) that may be more useful in peptic ulcer. Muscarinic blockers can also be used to reduce cramping and hypermotility in transient diarrheas, but opioids such as diphenoxylate (Chapter 31) are more effective. 

The pharmacokinetics of pirenzepine and cimetidine are not affected by the presence of the other drug, but pirenzepine increases the cimetidine-induced reduction in gastric acid secretion, which is an apparently advantageous interaction. ... 

Jamati F, Mahachai V, Reilly PA Thomson ABR. Lack of i iarmacokinetic interacticn between cimetidine and pirenzepine. Clin Pharmacol Ther (1985) 38,325-30. 

Scholten T, Fritsch WP, Muller JE, Hengels KJ (1982) The inhibition of vagally stimulated acid secretion by pirenzepine and cimetidine. Scand J Gastroenterol Suppl 72 169-171... 

---