When The Drugs Don’t Work

Medications are prescribed for a reason: to help people get well. In some rare cases, however, a medication can cause an allergic reaction. A medication allergy is not the same as a side effect. Side effects are known possible reactions which are always listed on the drug label. So what exactly is a medication allergy?

ReNue Rx What Is A Medication Allergy?

Signs and symptoms

The most common symptoms of a medication allergy are rash, hives, or fever. In addition to these most common symptoms, a medication allergy can also cause a runny nose, itching, sneezing, nausea, and coughing.

Typically, the symptoms of a severe medication allergy will begin within an hour after taking the medication. Other reactions, such as hives, may not occur until several hours or even days later. On rare occasions, a medication allergy can cause a serious reaction known as anaphylaxis. This life-threatening condition causes swelling of the face, lips, and throat, and difficulty breathing.

What causes medication allergies?

A medication allergy occurs when the body’s immune system has mistaken a medication for a harmful invader such as a bacterium or virus. The immune system then produces an antibody which is specific to that medication. Although the reaction can happen the first time the medication is taken, sometimes the antibodies won’t kick into action until the next time the medication is taken.

Complications of allergies

Sometimes, medication allergies can cause other, less common conditions. These may not show up until days or weeks after taking the medication. These can include serum sickness, medication-induced anemia, and inflammation of the kidneys.

Which drugs are commonly linked to allergies?

Although any medication can cause an allergic reaction, some are more commonly associated with allergies than others. These include antibiotics, over-the-counter pain relievers, chemotherapy drugs, and drugs for autoimmune disease. Some people have a higher risk of medication allergy, including those who have a family history of drug allergy or those who have a history of other allergies.

Do drug allergies need treating?

A medication allergy needs to be accurately diagnosed to prevent a harmful or fatal reaction. During a doctor’s appointment, the physician will ask about personal and family medical history and perform a physical examination before looking at any current medications. The doctor may also order additional tests or make a referral to an allergy specialist.

Any present allergy symptoms will be treated. Patients must stop taking the medication causing the allergic reaction and may need to be treated for withdrawal symptoms. The doctor may also prescribe an antihistamine or corticosteroids to block allergic reactions such as skin rash or hives.

Seek medical advice

Even people who have not had a reaction to a medication in the past may have one at some point. Anyone who is having an allergic reaction to medications should stop taking the medications and seek medical advice immediately. Medications which have already caused an allergic reaction should be avoided.


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