Antacids, like many other products, can affect the absorption or elimination of certain prescription drugs. Knowing this has forced me to temper my recommendation since most the people who ask me for advice are older and already using a prescription drug. For example, calcium reacts with digoxin, a heartbeat regulator, making the dose less effective. The same is true with the tetracycline antibiotics (there are many) or the anti-convulsant phenytoin (Dilantin).

The list doesn't end there. Other drugs weakened by antacids include anti-ulcer drugs (such as Pecid®, Tagamet®, Zanac®) nonsteroid antiinflammatory drugs like indomethacin (Indocin®), beta blockers that treat high blood pressure (Inderal® and Lopressor® are two examples) and the Parkinson's drug levodopa (Sinemet®). Thiazide diuretics (including Diuril®, Hygroon®, Hydro-chlor®),prescribed to treat high blood pressure are also a problem when combined with antacids because they caus the body to retain calcium and, believe it or not, a too high calcium blood level is VERY dangerous to your health since calcium, in addition to keeping bones strong, regulates the action of the heart.

The bottom line? Anyone taking a prescription drug should consult with their pharmacist before taking antacids for heartburn and gas or to prevent osteoporosis.