July 3, 2003 I take Tenormin and have been getting allergy shots without a problem. My doctor just recently noticed this situation and wants to chang my meds. Where can I get more information on the possible risks and their prevention? -- B.B., Indiana
Tenormin and other beta blockers are usually given to control high blood pressure or to treat heart conditions. They are also used sometimes to prevent migraine headaches.
Beta blocker eye drops are often used to treat glaucoma, and these can be absorbed from the eye into the blood stream.
When a beta blocker is used to control blood pressure or prevent migraine headaches, your physician can often switch it to a different medication.
Beta blockers may be used to treat heart flutters or heart failure. They are sometimes used to prevent heart attacks. It is often more difficult to treat heart conditions with a different medication.
Glaucoma is a very serious condition and beta blocker eye drops are usually the method of choice for treating it.
Taking beta blockers can increase your chances of having a severe allergy reaction. Beta blockers narrow the passages in the lungs and may bring on a life-threatening asthma attack.
Add to this the fact that beta blockers "block" your body's beta receptors. When you have a life-threatening allergic reaction, such as a reaction to an allergy shot, epinephrine (adrenaline) is usually the first, and often considered the most important, drug given.
Epinephrine stimulates the alpha and beta receptors to help reverse the serious allergic reaction. But epinephrine can't stimulate beta receptors in patients taking beta blockers if the beta receptors are blocked. So it is much more difficult to reverse a severe reaction to a shot, bee sting, or other allergy trigger in patients taking beta blockers.
For these reasons, most physicians feel the benefits are not worth the risk of giving allergy injections to patients taking beta blockers.
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