Guest guest Posted May 4, 1999 Report Share Posted May 4, 1999 Howdy Gene! One of these days I'm going to have to get a Goodman's. It is actually embarrassing not to have one but it is sooooo expensive. I've been relying on my Katzung's but I guess I'll have to hit up my rep. In the meantime, I'll get the specific references you've pointed out and read up on it. Thanks for the additional information. I'm gonna have to think about it awhile but I'm sure it'll be helpful. Take care, Jeff [texasems-L] Re: " Too little " Atropine Reply No. 2. Consult Goodman and Gilman's The Pharmacological Basis for Therapeutics, 8th edition, page 150, for a comprehensive explanation of atropine, scopolamine and related belladonna alkaloids. The actions of atropine on muscarinic receptors varies according to dose. This may be the reason for the statement about dosage. It takes a relatively high dose to compete with other agonists in the area. " The main effect of atropine on the heart is to alter the rate. Although the dominant response is tachycardia, the heart rate often decreases transiently with average clinical doses (0.4 to 0.6 mg.) The slowing is rarely marked, about 4 to 8 beats per minute, and is usually absent after rapid intravenous injection. There are no accompanying changes in blood pressure of cardiac output. " Id, p. 154. " This paradoxical effect was once thought to be due to central vagal stimulation; however, such cardiac slowing is also seen with antimuscarinic drugs that do not readily enter the brain. Recent studies in man show that pirenzepine is equipotent with atropine in decreasing heart rate; its prior administration can prevent any further decrease by atropine. The data suggest that the decreased heart rate is produced through blockade of M1 receptors on protganglionic parasympathetic neurons, thereby relieving the inhibitory effects of synaptic ADh on release of transmitter (Wellstein and Pitschner, 1988). " Id, p. 154. So there you have it! Gene Gandy, JD, LP ------------------------------------------------------------------------ SIGN UP NOW FOR FREE HOME IMPROVEMENT HOW-TO'S Receive seasonal how-to's and climate-specific advice via e-mail. http://clickhere./click/131 Quote Link to comment Share on other sites More sharing options...
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