Drugs commonly associated with allergic reactions were numerous and included aspirin, antibiotics, diuretics, oral diabetes drugs, anti-tuberculosis medications, dyes used in x-ray procedures, heart medications, vaccines, and drugs used to treat high blood pressure. The study, conducted by researchers from the University of South Alabama in Mobile, appears in the December 10 issue of The Journal of the American Medical Association.

In addition to allergic reactions to drugs, patients can also experience intolerance to a specific drug or an unusual reaction not usually seen with a given drug. These types of drug reactions are known as type B adverse reactions and are not widespread. Although allergic reactions occur each year in small numbers of patients, physicians can usually prevent these reactions from occurring by knowing the risk factors for drug allergy and for the patient, and knowing how to recognize early signs of allergic reaction such as fever and rash.

More common adverse reactions to drugs -- known as type A -- are overdosing, side effects and drug interactions, which can occur when the patient is taking two or more medications simultaneously.

Other problems can be encountered when a patient requires a drug to which they claim to have had a previous reaction. Drs. Richard D. deShazo and Stephen F. Kemp, authors of the new study, outline an approach for doctors to use when determining the type and extent of a patient's previous adverse drug reaction. This system can help doctors decide if it is safe to give the drug in a modified dose or if they need to substitute another drug to avoid a reaction.

For patients who experience a reaction while taking more than one drug, the authors state that the goal is "to abort the reaction and simultaneously identify the culprit drug and the alternate drug for which there is an urgent indication."

One of the most severe types of drug reactions is the acute, life-threatening reaction known as anaphylaxis, which usually develops rapidly. Symptoms include skin redness, itching, hives, difficulty breathing, low blood pressure, abnormal heart rate and swelling of the skin, larynx and other areas. If caught early, anaphylaxis is easily treated with epinephrine.

The authors point out that the U.S. Food and Drug Administration maintains a surveillance system known as MedWatch to monitor reports of adverse drug reactions. Consumers can access the MedWatch Web site at http://www.fda.gov/medwatch to view newly reported reactions to prescription drugs that are posted each month.

December 10, 98
SOURCE: The Journal of the American Medical Association