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Workers' Comp

Ask The Pharmacist: Drug Allergies Versus Side Effects in Workers’ Comp

June 2, 2023

Spencer Sherman, Pharm.D.

Clinical Pharmacist, Pharmacy Solutions

What's the difference between a drug allergy and a side effect?

True medication allergies are rarer than side effects, but are potentially more dangerous, and are a result of the activation and response of the body’s immune system to an “insult” or “foreign body.” Allergies occur across a range of severities, from mild to life-threatening, and often only occur on the second exposure to the drug, food or substance that triggers it.

Mild allergy symptoms might include hives, rash or itchy skin, while more serious ones encompass throat tightness, difficulty breathing, swollen face, lightheadedness, reddened skin or blisters, or anaphylaxis (whole-body shock with life threatening low blood pressure). It’s important to seek medical attention quickly if these serious symptoms occur when taking a medication.  

Treatment of acute drug allergies may include antihistamines, bronchodilators and/or corticosteroid medications to manage symptoms. Epinephrine injections may be used to treat anaphylaxis.

Before starting a new medication, be sure to advise an injured employee to let their doctor know about any drug reactions they have had in the past and to update the list of other prescribed medications, supplements or vitamins they may be taking.

Medications, supplements and vitamins all have an expected range of physiologic effects when consumed. The desired therapeutic effect of a drug is called its indication for use. A side effect is a known, but unwanted reaction listed in the drug labeling that may occur, even when a medication is administered correctly. Side effects are not uncommon and may be mild, (e.g., a runny nose) or more severe (e.g., increased risk of a heart attack). They can occur when patients begin taking a new medication, supplement, or vitamin, if they suddenly stop taking one that they’ve used for some time, or if they increase or decrease the amount of the substance they take. A patient’s age and gender as well as the medication's route of administration, absorption differences, kidney function, as well as co-administered medicines, foods or supplements can all affect the likelihood of experiencing a side effect.

Common, milder side effects of medications include headache, insomnia, gastrointestinal distress, dry mouth, blurred vision and skin rashes. Serious side effects are rarer and might include heart rhythm disturbances, liver failure, sedation or loss of consciousness, respiratory depression, etc.

Managing side effects, in general, involves prevention and management strategies, including determining whether the benefit of the medication outweighs the impact or risk of the side effect.

The similarities between drug allergies and side effects are that symptoms of both may range from uncomfortable to life threatening. Prevention of both includes some strategies in common, such as identification and avoidance. A crucial difference is in recognizing the contribution to serious allergic reactions of the immune system and tailoring treatments and prevention strategies accordingly for the best outcome.

This information is meant to serve as a general overview, and any specific questions or concerns should be more fully reviewed with your health care professional such as the prescribing doctor or dispensing pharmacist.

Do you have a workers’ compensation or auto-related pharmacy question? Send us an email at AskThePharmacist@mitchell.com.

To read more Ask The Pharmacist articles, please visit mitchell.com/ask-the-pharmacist.