Drug Allergy

Any drug can cause an adverse drug reaction, which can range from a mild rash or hives to a life-threatening allergic reaction. There is a difference between being allergic to a drug and having a side effect from a drug. Prescription and over-the-counter medications provide instructions that should always be read and followed regarding proper use and side effect warnings. Some mild reactions to drugs are considered an adverse drug reaction, but are not considered a drug allergy. If you experience any drug-related symptoms, report them to your healthcare provider.

True allergic responses to drugs can affect most major organs including the skin, lungs, liver, kidneys, and blood vessels. The drugs most likely to cause these problems are antibiotics, certain vaccines, anti-seizure medicines, contrast dyes used for some x- rays, some heart and cancer drugs, and local anesthetics (like novacaine that dentists may use).

Common drug allergy symptoms include:

* itching of the skin or eyes
* skin rash or
* hives

Other more serious symptoms include:

* wheezing or breathing problems and
* anaphylactic shock

Emergency treatment may be required for an anaphylactic reaction, the most serious type of allergic reaction. Symptoms of hives, itching, and swelling usually appear within seconds or minutes after exposure and additional symptoms can ultimately result in severe respiratory distress, loss of consciousness, and even death if left untreated. Antibiotics, such as penicillin, can trigger this serious drug reaction in some people.

Diagnosis of drug allergy is based mostly on patient history. This requires that the healthcare provider be told of every drug that was taken at the time of a reaction, including prescription, over-the-counter, and herbal medicines. Once the drug that caused the reaction is identified, future use of that drug should be avoided. If an adverse drug reaction occurs while in the hospital, blood tests can be done to identify the drug causing the reaction. Following a drug allergy reaction, a provider may recommend that an allergist, a doctor who specializes in allergies, be seen.

Some people are allergic to antibiotics. The most common is penicillin, which belongs to the family of beta-lactam antibiotics. No one is born allergic to penicillin, nor can it be inherited. However, anyone can develop an allergy to penicillin after exposure to it. Most often the reaction is either hives or rashes that are itchy or irritating and that occur within 2 to 3 days of starting the medication. Sometimes a delayed reaction can occur after several weeks. Having an allergy to penicillin does not mean you are allergic to all antibiotics. If a penicillin allergy is suspected, the best way to confirm it is with a skin test.

Prevention of a recurrence of a drug allergy is achieved through strict avoidance of the drug in the future. This means being aware of hidden sources of the drug because it may be an ingredient in another medication. For future reference, keep the names written down of all drugs that caused the adverse reaction and keep this list in an easy to remember location. Be sure to check all labels for the names of these drugs before taking any over-the-counter and herbal medicines.