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SafeMedicationUse Newsletter

Know What to Do if You Are Allergic to a Medicine!

2012-03-08 has received reports from consumers who were given medicines to which they were allergic. One report involved a consumer who was allergic to the antibiotic penicillin. People who are allergic to penicillin should not take antibiotics in the penicillin family, such as amoxicillin. The consumer reported the allergy at the dentist's office, but did not write this information in the correct spot on the form. The consumer also informed the pharmacy about the allergy, but the information was not kept on file. Later, the dentist prescribed amoxicillin for the consumer, and the pharmacy dispensed the medicine. Fortunately, the consumer read the information that the pharmacy supplied with the medicine and realized that a mistake had been made. The consumer spoke up, and a different antibiotic was prescribed.

A second report involved a consumer who was allergic to another antibiotic, called levofloxacin. This consumer reported the allergy on a list of medicines that was given to healthcare providers when the consumer came to a hospital for treatment. Despite taking this precaution, the consumer was given levofloxacin. The report sent to stated that the consumer "could not get breath at all, almost died".

Some allergies cause only mild symptoms, but taking a medicine to which you are allergic could cause severe harm or even death. If you have an allergy to a medicine, it is very important that you take steps to avoid receiving the medicine. has the following tips for consumers who have allergies to medicines:
  • Seek advice from a healthcare provider if you notice any unexpected or bothersome effects after taking a medicine. Provide a detailed description of the symptoms. This is important, because side effects are sometimes confused with allergies. Additional information or tests may be needed to determine whether you have experienced an allergy or a side effect. (See text box, "What's the Difference between an Allergy and a Side Effect?")
  • Learn the generic and trade names of any medicines that you are allergic to. Make sure that you tell your healthcare providers about your allergies every time you receive care. Explain why you cannot take the medicine, and describe any symptoms you experienced when you took the medicine in the past.
  • Keep a list of all your medicines, and be sure to note your allergies on the list. Show the list to healthcare providers any time you receive care. Read more
  • Always read the information that the pharmacy provides with your medicine. If you have any questions or concerns, ask your pharmacist.
  • Before accepting any medicine, ask what you are being given. Remind your healthcare provider that you have an allergy to a medicine. Speak up if you think you might be receiving something that you are allergic to. Read more
  • If you are allergic to one particular medicine, you may also be allergic to other similar medicines. Be sure to check with a healthcare provider before taking any new medicine, even one that does not require a prescription.
  • Ask your healthcare provider whether you should carry an epinephrine auto-injector, such as EpiPen or Twinject. If you need to carry an epinephrine auto-injector, make sure that you know how to use it. In addition, make sure that anyone who might need to give you an injection in an emergency knows how to use this device. Read more
  • Severe allergic reactions (also called anaphylaxis or anaphylactic reactions) can cause death and therefore require immediate medical attention. If you or a family member experiences symptoms of anaphylaxis, such as difficulty breathing or fainting, call 9-1-1 or your local emergency response centre. For more information on anaphylaxis, see
  • Consider wearing a MedicAlert bracelet with information about your allergies and/or other medical conditions. A MedicAlert bracelet may save your life if you can't speak in an emergency situation.
What's the Difference between an Allergy and a Side Effect?

An allergy is a reaction caused by your body's immune system. Symptoms caused by allergies can range from mild to severe. For example, symptoms may include a runny nose, itchy eyes, skin reactions such as a rash or hives, nausea, vomiting, diarrhea, feeling faint, swelling of the lips or tongue, and difficulty breathing. If you experience any of these symptoms after taking a dose of medicine, you should consult a healthcare provider. Severe allergic reactions (also called anaphylaxis or anaphylactic reactions) can cause death and therefore require immediate medical attention. If your healthcare provider states that you are allergic to a medicine, it is important to avoid taking that medicine in the future. Sometimes even a mild allergic reaction can lead to a more severe reaction if you take the medicine again.

A side effect is an unintended but often predictable effect that occurs when medicines are used correctly. Side effects are generally caused by a known action of the medicine. Most side effects are mild, reversible, and not life-threatening. However, side effects can range from mild to severe, and they vary greatly from one medicine to another. Whenever you receive a new medicine from a pharmacy, you should be given information about the medicine, including possible side effects. It is important to read this information, so that you will be aware of the symptoms of any serious side effects that may occur. If you experience such a symptom, or any bothersome or unexpected effect, it is important to contact a healthcare professional. Your healthcare provider may advise you to continue taking the medicine as directed or may suggest that you reduce the dose. For a serious side effect, you may be told to stop taking the medicine.

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