Allergies to Medications
Drug allergies arise from a complicated response by the immune system to a specific medication. A person usually goes through three stages when developing an allergy to a medication. First, he or she must be exposed to the drug by taking one or more doses. Next, the person’s immune system identifies the drug as harmful and begins producing antibodies to fight it. Finally, the person takes another dose of the drug, and the allergy symptoms appear. The symptoms may appear immediately, within 1 to 2 hours, or within a few days to a week after taking the drug. Common symptoms of drug allergy include skin rash or hives, difficulty breathing, and itching. Severe drug allergies may cause seizures, loss of consciousness, or shock. If you have had a previous severe allergic reaction, you will need to carry an injecting device that contains epinephrine with you at all times, so you can inject yourself immediately if you have another allergic reaction. An injection of epinephrine can save your life.
Medications that typically produce an allergic reaction include antibiotics (such as penicillin), sulfa drugs, insulin that contains pig or ox protein, vaccines, and aspirin. If you are allergic to any medications, be sure to tell your doctor and other healthcare providers who are treating you, such as a nurse or a dentist. Also, in case of emergency, you should always wear a medical identification bracelet or necklace and carry a wallet card that informs people of your allergy. This will help ensure appropriate medical treatment.