What are Medication Allergies?
For the purposes of evaluating patients with medication reactions, it is important to distinguish between a true medication allergy and a sensitivity.
- An allergy involves an inappropriate immune response to a medication, with rapid onset of symptoms including hives and swelling (urticaria and angioedema), and difficulty breathing, consistent with anaphylaxis.
- A sensitivity can vary widely from patient to patient, but is often related to commonly reported side effects, intolerance for the medication, or interactions with other drugs.
Only about 5% to 10% of reactions are due to a true medication allergy.
Certain medications are more likely to produce allergic reactions than others. The most commonly reported are:
- Antibiotics, such as penicillin
- Aspirin and non-steroidal anti-inflammatory medications (NSAIDs), such as ibuprofen