Negative chronotropic effects of nizatidine
Peptic ulcer is a condition in which the wall of the digestive tract is damaged by stomach acid. A common treatment for this condition is the administration of drugs that cause a reduction in the level of gastric acid secretion. Since histamine causes increases in acid secretion, drugs that block histamine type 2 (H2) receptors are often used. H2 receptors are also located on heart tissue, where they increase the force of cardiac contraction (an inotropic effect) and the heart rate (a positive chronotropic effect). Although the most widely used drugs that block H2 receptors (H2 blockers), cimetidine and ranitidine, do not have any apparent effect on heart function, more recently developed H2 blockers with increased potency may, in fact, have cardiovascular effects. To evaluate the effects of nizatidine, a new and powerful H2 blocker, on various aspects of cardiovascular function, a controlled, randomized study was carried out using 12 healthy volunteers. The subjects received either nizatidine or famotidine (one of the older class of less-potent H2 blockers), or a placebo (inactive) drug orally for one week, then crossed over to receive either the placebo or one of the drugs for a second week. Cardiovascular performance was evaluated at regular intervals after drugs were given during rest and during maximal exercise. Three hours after drug administration, nizatidine caused a significant reduction in heart rate, whereas famotidine had no such effect. Nizatidine administration also slightly but significantly reduced the increase in heart rate seen with exercise. When combined with atenolol (a beta-blocker), taken by many patients for cardiac disorders, there was an additional decrease in heart rate over that induced by atenolol alone. Hence, patients receiving nizatidine must be carefully monitored with respect to other medications they may be taking to prevent any adverse drug interactions from occurring. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Gut
Botulinum toxin: a deadly poison sheds it negative image
Research is proving botulinum toxin to be a valuable treatment for certain medical problems. Botulinum toxin is a powerful nerve poison produced by the organism Clostridium botulinum. Under the right conditions, it can cause an extremely deadly type of food poisoning. However, the same characteristics that make the toxin so dangerous also make it ideal for treatment of conditions involving localized, chronic muscle spasms. Because its paralytic action is so specific, treatment has long duration and little chance of side effects.
Publication Name: Annals of Internal Medicine
The FDA has approved the drug rabeprazole for the treatment of stomach ulcers, gastroesophageal reflux disease and Zollinger-Ellison syndrome. Sold under the trade name Aciphex, it is a proton pump inhibitor similar to omeprazole and lansoprazole. Although it is very effective in healing stomach ulcers, it has no advantage over omeprazole or lansoprazole and costs about as much.
Publication Name: Medical Letter on Drugs and Therapeutics
- Abstracts: Claudification: stepping out of the poor circulation problem. Leg ulcers: veins are the problem more than half of the time
- Abstracts: Multichannel biomagnetic system for study of electrical activity in the brain and heart. Babies' brain scan noise research
- Abstracts: New serologic tests for early detection of coccidioidomycosis. Stillbirth evaluation: what tests are needed?
- Abstracts: General public education. Continuing education program
- Abstracts: Treatment of lichen sclerosus with topical dihydrotestosterone. The long-term effectiveness of hysteroscopic treatment of menorrhagia and leiomyomas