Reactions to medication are extremely common, with 15% of hospitalized patients experiencing an unintended reaction as a result of medication, and 25% of patients evaluated in outpatient clinics reporting an adverse reaction to at least one medication. However, trueallergicreactions to medications only account for about 5 to 10% of all adverse drug reactions.
People can experience allergic reactions to just about any medication. Most adverse drug reactions are common and predictable, while others may be erratic or may only affect those who have a predisposition to them.
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Allergic Reactions to Medications
True allergic reactions to medications typically have certain features:
Symptoms of Allergic and Immunologic Reactions
Skin rashes are the most common symptoms of adverse drug reactions.Urticaria and angioedema(hives and swelling) suggest an allergic cause, while blistering, peeling, and sunburn-like reactions suggest non-allergic immunologic causes.
Other non-allergic immunologic symptoms can include:
Drug Allergy to Penicillin
About 1 in every ten people report a history of an allergic reaction to penicillin, but less than 1 % of the population is actually allergic to this drug. A true allergy to penicillin could cause life-threatening anaphylaxis as a result.
Drug Allergy to Cephalosporins
Severe reactions to cephalosporins, a class of antibiotics, are much less common than reactions due to penicillins. However, if you have a true penicillin allergy, there is a small chance that you could also react to cephalosporins.
Drug Allergy to NSAIDs
Non-steroidal anti-inflammatory drugs(NSAIDs) include pain relievers such as aspirin, ibuprofen, and naproxen. Allergies to these medications can cause allergic and non-allergic bouts of hives and swelling, worsen asthma, and cause anaphylaxis.
A Reaction to IV Contrast Dye
The reaction to IV contrast dye is non-allergic but can result in anaphylaxis since the dye can cause mast cells to release their contents, mimicking an allergic reaction.
Drug Allergy to Local Anesthetics
True allergic reactions tolocal anesthetics(novocaine, lidocaine) are extremely rare and are usually due to other ingredients in the medication, such as preservatives or epinephrine.
Non-Allergic Reactions to Antiseizure Medications
Many antiseizure medications used forepilepsytreatment cause non-allergic reactions as a result of certain enzyme deficiencies. Symptoms can include:
Managing an Allergic Reaction
If you have difficulty breathing or develop any other symptoms that could be life-threatening, seek medical help immediately.
If you are having a medication reaction that’s affecting only your skin and/or does not seem life-threatening, stop taking the medication and promptly call your healthcare provider or their on-call hotline to see how you should proceed.
Reactions can get worse with continued use of a medication, so ask your healthcare provider if you should keep taking the medication.
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Khan DA, Solensky R.Drug allergy.J Allergy Clin Immunol. 2010;125(2 Suppl 2):S126-37. doi:10.1016/j.jaci.2009.10.028Medications And Drug Allergic Reactions. American Academy of Allergy Asthma & Immunology.Frew A.General principles of investigating and managing drug allergy.Br J Clin Pharmacol.2011;71(5):642-6. doi:10.1111/j.1365-2125.2011.03933.xIs It Really A Penicillin Allergy?Centers for Disease Control and Prevention.Is It Possible To Be Allergic To Aspirin?American Academy of Allergy Asthma & Immunology.CT and X-ray Contrast Guidelines: Allergies and Premedication. University of California San Francisco Department of Radiology and Biomedical Imaging.Lee J, Lee JY, Kim HJ, Seo KS.Dental anesthesia for patients with allergic reactions to lidocaine: two case reports.J Dent Anesth Pain Med. 2016;16(3):209-212. doi:10.17245/jdapm.2016.16.3.209Drug-induced liver injury. US National Library of Medicine. October 2018.
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Khan DA, Solensky R.Drug allergy.J Allergy Clin Immunol. 2010;125(2 Suppl 2):S126-37. doi:10.1016/j.jaci.2009.10.028Medications And Drug Allergic Reactions. American Academy of Allergy Asthma & Immunology.Frew A.General principles of investigating and managing drug allergy.Br J Clin Pharmacol.2011;71(5):642-6. doi:10.1111/j.1365-2125.2011.03933.xIs It Really A Penicillin Allergy?Centers for Disease Control and Prevention.Is It Possible To Be Allergic To Aspirin?American Academy of Allergy Asthma & Immunology.CT and X-ray Contrast Guidelines: Allergies and Premedication. University of California San Francisco Department of Radiology and Biomedical Imaging.Lee J, Lee JY, Kim HJ, Seo KS.Dental anesthesia for patients with allergic reactions to lidocaine: two case reports.J Dent Anesth Pain Med. 2016;16(3):209-212. doi:10.17245/jdapm.2016.16.3.209Drug-induced liver injury. US National Library of Medicine. October 2018.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Khan DA, Solensky R.Drug allergy.J Allergy Clin Immunol. 2010;125(2 Suppl 2):S126-37. doi:10.1016/j.jaci.2009.10.028Medications And Drug Allergic Reactions. American Academy of Allergy Asthma & Immunology.Frew A.General principles of investigating and managing drug allergy.Br J Clin Pharmacol.2011;71(5):642-6. doi:10.1111/j.1365-2125.2011.03933.xIs It Really A Penicillin Allergy?Centers for Disease Control and Prevention.Is It Possible To Be Allergic To Aspirin?American Academy of Allergy Asthma & Immunology.CT and X-ray Contrast Guidelines: Allergies and Premedication. University of California San Francisco Department of Radiology and Biomedical Imaging.Lee J, Lee JY, Kim HJ, Seo KS.Dental anesthesia for patients with allergic reactions to lidocaine: two case reports.J Dent Anesth Pain Med. 2016;16(3):209-212. doi:10.17245/jdapm.2016.16.3.209Drug-induced liver injury. US National Library of Medicine. October 2018.
Khan DA, Solensky R.Drug allergy.J Allergy Clin Immunol. 2010;125(2 Suppl 2):S126-37. doi:10.1016/j.jaci.2009.10.028
Medications And Drug Allergic Reactions. American Academy of Allergy Asthma & Immunology.
Frew A.General principles of investigating and managing drug allergy.Br J Clin Pharmacol.2011;71(5):642-6. doi:10.1111/j.1365-2125.2011.03933.x
Is It Really A Penicillin Allergy?Centers for Disease Control and Prevention.
Is It Possible To Be Allergic To Aspirin?American Academy of Allergy Asthma & Immunology.
CT and X-ray Contrast Guidelines: Allergies and Premedication. University of California San Francisco Department of Radiology and Biomedical Imaging.
Lee J, Lee JY, Kim HJ, Seo KS.Dental anesthesia for patients with allergic reactions to lidocaine: two case reports.J Dent Anesth Pain Med. 2016;16(3):209-212. doi:10.17245/jdapm.2016.16.3.209
Drug-induced liver injury. US National Library of Medicine. October 2018.
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