Posted by dcruik518 on February 22, 2009, at 23:29:39
In reply to Antacids affecting serum levels of medication, posted by twinch42085 on February 19, 2009, at 9:13:11
I'm not sure that Milk of Magnesia is an antacid--isn't more of a laxative?? Maybe it has a little antacid in it. If you do have an acid problem, the acid--not the antacid!--will eat away at your esophagus and dramatically increase the likelihood of esophageal cancer. So if you have acid reflux, you should see a doctor and get on a good med for it.
As for the drug interaction, that's a good question. From what I understand antacids can increase the absorption of amphetamine by making your stomach more alkaline; they may also decrease the elimination of amphetamine to the extent that they affect the pH of your urine. How significant this effect is I don't know.. Here's what I found:
"with normal urine pHs approximately half of an administered dose of amphetamine is recoverable in urine as derivatives of alpha-hydroxy-amphetamine and approximately another 30%-40% of the dose is recoverable in urine as amphetamine itself. Since amphetamine has a pKa of 9.9, urinary recovery of amphetamine is highly dependent on pH and urine flow rates. Alkaline urine pHs result in less ionization and reduced renal elimination, and acidic pHs and high flow rates result in increased renal elimination with clearances greater than glomerular filtration rates, indicating the involvement of active secretion. Urinary recovery of amphetamine has been reported to range from 1% to 75%, depending on urinary pH, with the remaining fraction of the dose hepatically metabolized.
poster:dcruik518
thread:881048
URL: http://www.dr-bob.org/babble/20090213/msgs/881807.html