Key TakeawaysThe most common prescription medication people are allergic to is penicillin, but true drug allergies are rare.There is no way to know for sure that you’re allergic to a medication before you take it.If you have any symptoms or reactions after starting a new medication, tell your healthcare provider right away.
Key Takeaways
The most common prescription medication people are allergic to is penicillin, but true drug allergies are rare.There is no way to know for sure that you’re allergic to a medication before you take it.If you have any symptoms or reactions after starting a new medication, tell your healthcare provider right away.
Starting a new medication can be nerve-wracking, especially if you’re worried about side effects or even having an allergic reaction to a drug you’ve never taken.
While it’s not possible to find out if you have a medication allergy before you start taking it, there are a few ways you can work with your prescribing provider to mitigate your risk of a reaction.
How to Tell If You Have Allergies
If you have a history of drug allergies or have had reactions to medications in the past, tell your healthcare provider. They can start you with a small “test” dose of a medication to see how you react.
Most drug allergy symptoms come on within hours of taking a medication, but reactions can be delayed for up to two weeks later.
“The key is to keep in mind that an allergy to a medication is rare,”Maya R. Jerath, MD, PhD, clinical director of the Division of Allergy and Immunology at Washington University in Saint Louis, told Verywell. “Adverse side effects or intolerances certainly happen more often, but these are not true allergies.”
Here’s how the two are different:
The Different Types of Adverse Drug Reactions
Risk Factors for a Medication Allergy
Many people believe that having a family history of a drug allergy will also make them develop the same allergy—but Jerath said that’s not necessarily true.
“People do not inherit medication allergies,” said Jerath. “The tendency to be an allergic person is inherited, but specific allergies are not.”
While family history alone does not play a major role in the development of drug allergies, other factors can make a drug allergy more likely.
Jyothi Tirumalasetty, MD, clinical assistant professor at Stanford University with a focus on allergy and immunology, told Verywell that certain genetic factors and chronic health conditions can make drug allergies more likely.
Some risk factors for medication allergies include:
How Common Are Drug Allergies?
ADRs are fairly common, affecting up to 25% of people taking certain medications. However, only 5%–10% of ADRs are true allergies.Women are more likely to develop a drug allergy than men.
Diagnosinga drug allergy can be tricky, butallergiststypically start with a complete medical history that includes:
Always tell your provider about any reactions you’ve had to any medications. Experts recommend drug allergy testing for people who have had adverse drug reactions in the past, as well as when there is not a safe alternative to the drug prescribed.
Risk Factors for Allergic Reactions
What Are the Most Common Drug Allergies?
All drugs carry the risk of an allergic reaction, but there are certain classes of medications that are more common for people to be allergic to, including:
These drugs are frequently used to treat many acute and chronic conditions, so patients may run into situations where they are allergic to a medication that’s being recommended for them.
Jerath said that while this happens often, there are “desensitization procedures” that allow providers to work around it.
For example, if a patient is allergic to penicillin and has an infection that requires penicillin, Jerath said that there is a “certain way of administering the medicine in a graded incremental fashion that makes your immune system not react.”
While this method does not cure an allergy, it does allow a patient to get the needed medication in an emergency.
The Most Common Medication Allergies
What to Watch For When Starting a New Medication
If your provider prescribes a new medication for you, talk to them about side effects and the possibility of an adverse reaction. While you can’t know for sure if you’ll react before you start a medication, there are some clues you can be on the lookout for.
The signs and symptoms of ADR and allergic reactions are different. Allergic reactions start on the skin, while ADR usually comes on as gastrointestinal symptoms like nausea, vomiting, stomach cramps, and diarrhea.
Signs that you might be having a reaction to a medication include:
It’s less common but some people develop a severe, life-threatening allergic reaction (anaphylaxis) to a drug. If symptoms like trouble breathing, itching, dizziness, confusion, andswelling in your lips or facecome on suddenly after you take a medication, call 911.
What This Means For YouTrue drug allergies are rare but they can happen. If you’re starting a new medication and you’re nervous about side effects or adverse reactions, talk to your provider. While you can’t know for sure if you’re allergic until you take the drug, your provider can start you on a lower dose and watch for symptoms or recommend an alternative.
What This Means For You
True drug allergies are rare but they can happen. If you’re starting a new medication and you’re nervous about side effects or adverse reactions, talk to your provider. While you can’t know for sure if you’re allergic until you take the drug, your provider can start you on a lower dose and watch for symptoms or recommend an alternative.
Can Medications Trigger Food Allergies?
4 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.American Academy of Allergy, Asthma, and Immunology.Medications and drug allergic reactions.Wheatley LM, Plaut M, Schwaninger JM, et al.Report from the National Institute of Allergy and Infectious Diseases workshop on drug allergy.J Allergy Clin Immunol. 2015;136(2):262-271.e2. doi:10.1016/j.jaci.2015.05.027De Martinis M, Sirufo MM, Suppa M, Di Silvestre D, Ginaldi L.Sex and gender aspects for patient stratification in allergy prevention and treatment.Int J Mol Sci. 2020;21(4):1535. doi:10.3390/ijms21041535American College of Allergy, Asthma, and Immunology.Drug allergies.
4 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.American Academy of Allergy, Asthma, and Immunology.Medications and drug allergic reactions.Wheatley LM, Plaut M, Schwaninger JM, et al.Report from the National Institute of Allergy and Infectious Diseases workshop on drug allergy.J Allergy Clin Immunol. 2015;136(2):262-271.e2. doi:10.1016/j.jaci.2015.05.027De Martinis M, Sirufo MM, Suppa M, Di Silvestre D, Ginaldi L.Sex and gender aspects for patient stratification in allergy prevention and treatment.Int J Mol Sci. 2020;21(4):1535. doi:10.3390/ijms21041535American College of Allergy, Asthma, and Immunology.Drug allergies.
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.
American Academy of Allergy, Asthma, and Immunology.Medications and drug allergic reactions.Wheatley LM, Plaut M, Schwaninger JM, et al.Report from the National Institute of Allergy and Infectious Diseases workshop on drug allergy.J Allergy Clin Immunol. 2015;136(2):262-271.e2. doi:10.1016/j.jaci.2015.05.027De Martinis M, Sirufo MM, Suppa M, Di Silvestre D, Ginaldi L.Sex and gender aspects for patient stratification in allergy prevention and treatment.Int J Mol Sci. 2020;21(4):1535. doi:10.3390/ijms21041535American College of Allergy, Asthma, and Immunology.Drug allergies.
American Academy of Allergy, Asthma, and Immunology.Medications and drug allergic reactions.
Wheatley LM, Plaut M, Schwaninger JM, et al.Report from the National Institute of Allergy and Infectious Diseases workshop on drug allergy.J Allergy Clin Immunol. 2015;136(2):262-271.e2. doi:10.1016/j.jaci.2015.05.027
De Martinis M, Sirufo MM, Suppa M, Di Silvestre D, Ginaldi L.Sex and gender aspects for patient stratification in allergy prevention and treatment.Int J Mol Sci. 2020;21(4):1535. doi:10.3390/ijms21041535
American College of Allergy, Asthma, and Immunology.Drug allergies.
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