Information for the public

Contacting a healthcare professional if you think you have a drug allergy

Contacting a healthcare professional if you think you have a drug allergy

If you think you are having an allergic reaction to a drug you should see a healthcare professional. This may be your GP or, for severe reactions, A&E staff. They should examine you and ask you questions about your symptoms. They should ask you how soon your symptoms started after you took the drug or how many doses you took, and whether you have had a similar reaction to that drug or type of drug before. They will need as much detail as you can give about the drug (bring the packaging if you can) and your reaction to it. They should also check that there is no other possible reason for your symptoms.

If your doctor thinks you might have a drug allergy they should discuss what this means with you (and your family members or carers as appropriate). They should also give you some written information about it. They will usually tell you to stop taking the drug and make sure you understand which drug or type of drug you need to avoid in future. This applies to any drug, whether it has been prescribed or bought over the counter. Check with a pharmacist before taking any over‑the‑counter medicines, because they can contain several different drugs.

Your doctor will offer you advice and treatment if needed to help relieve your symptoms. If your reaction is severe you will be sent to hospital for treatment.

NICE has also produced advice about having emergency treatment for anaphylaxis. See Other NICE guidance for more information.

Recording your suspected drug allergy

Your doctor should clearly state the following information about your suspected drug allergy in your medical records:

  • the name (or names) of the drug or drugs thought to have caused the reaction

  • the strength of the drug and what form you took it in (for example, tablet or liquid)

  • how you were taking it (for example, by mouth or injection)

  • how many doses you had taken or how long you had been taking the drug when symptoms started

  • your symptoms

  • why you were taking the drug

  • the date and time of the allergic reaction

  • which drug or drugs you need to avoid in future.

When you need to go to a specialist drug allergy service

Your doctor might refer you to a specialist drug allergy service for tests and advice. This depends on the kind of reaction you had, how severe it was and if you have any other medical conditions. Your doctor should refer you if they think you have had anaphylaxis or a severe skin reaction to a drug. They should also refer you if you have a medical condition that means you need to take the same drug or type of drug that caused your suspected allergy. For more information about when you might be referred, see the section on Specific drug allergies.

After you see a specialist, they should give you written information about:

  • your reaction and the drug that caused it

  • the tests you have had

  • your diagnosis (whether you had an allergic reaction or not)

  • which drug or drugs you need to avoid in future

  • any safe alternative drugs you can use.

If the tests showed that your symptoms were not caused by an allergic reaction to a drug you should be told that you can take that drug again safely. All of this information should be added to your medical records.

  • Information Standard