Advice on managing allergies and sensitivities to medications

Medications are essential for managing a wide range of health conditions. However, for some individuals, they can also trigger allergic reactions, from mild rashes to life-threatening anaphylaxis. Accredited Pharmacist and Credentialled Diabetes Educator Neha Patel explains how to identify, manage, and reduce the risk of medication-related allergies in clinical practice.

What is an allergy or allergic reaction?

An allergic reaction occurs when the immune system overreacts to a normally harmless substance (allergen). Allergens can include dust mites, pets, pollens, moulds, foods, insect stings, and medications.

For some individuals, exposure to an allergen triggers the immune system to produce antibodies that attach to mast cells. When these cells release histamine and other chemicals, allergy symptoms occur.

Common symptoms may include:

Runny or itchy nose
Sneezing
Watery eyes
Swollen lips
Skin rash or hives
Difficulty breathing
Asthma
Eczema
Stomach upset or colic

Reactions can range from mild to severe. Mild to moderate allergies are often treated with antihistamines, corticosteroid creams, or nasal sprays. Severe reactions (anaphylaxis) require urgent treatment with adrenaline.

Drug or medication allergies

An allergic reaction that occurs within one to six hours is referred to as an immediate reaction, and a reaction that occurs after 24 hours is called a non-immediate reaction.

Everyone reacts to medications differently, some people do not react at all, while for others taking a certain medication can turn into a life-threatening reaction. It is important to remember that all medicines can cause allergic reactions, but not everyone experiences them.

It is therefore important to identify and avoid medications that trigger allergic reactions. If your client suspects a medication allergy, they should consult a healthcare professional immediately. Allergies should be documented in the person’s medical records to prevent future adverse reactions. In some cases, alternative medications or treatment options may be available.

The diagnosis of drug-related allergies is mainly made from the clinical history as there are few specific and accurate diagnostic tests. Testing for drug allergy is available in Australia, through a skin test.

Antibiotic allergies

Penicillin is one of the most commonly reported drug allergies.

Allergic reactions to penicillin are broadly categorised as immediate and non-immediate reactions. Immediate reactions include hives, angioedema, respiratory distress, and anaphylaxis. Non-immediate reactions can manifest as rashes, fever, and other less severe symptoms.

Penicillin allergy is a significant concern in medical practice, impacting antibiotic prescribing and client outcomes.

It is estimated that about 10% of the population reports penicillin allergy, but studies suggest that up to 90% of these individuals may not be allergic. Many of these reported allergies are based on childhood reactions that may have been misdiagnosed or have been resolved over time.

Mislabelling clients with a penicillin allergy can lead to the use of less effective or more toxic antibiotics, contributing to antibiotic resistance and increased healthcare costs.

Proper diagnosis through detailed history, skin testing, and oral challenges can help identify true allergies and reduce unnecessary avoidance. Effective management involves accurate documentation, client education, and the careful use of alternatives or desensitisation protocols.

By improving the accuracy of penicillin allergy diagnosis and management, healthcare providers can ensure better client care, reduce antibiotic resistance, and optimise the use of one of Medicine’s most valuable antibiotics.

Sulphur allergies

Sulphur, a non-metallic element found abundantly in nature, is essential for life. Sulphur plays an important role in the structure of amino acids and proteins. Generally, a sulphur allergy is not an allergy to elemental sulphur but rather to compounds containing sulphur, such as sulphites or sulpha drugs.

It is important to distinguish between sulphite sensitivity, commonly associated with preservatives, and sulphonamide allergy, linked to a class of antibiotics.

Sulphonyl urea medications are one treatment option for people living with type 2 diabetes. Sulphonylureas directly stimulate insulin secretion; examples include Gliclazide, Glimepiride and Glipizide. Clients allergic to sulphur-containing drugs may not be allergic to sulphonylureas. Sulphonylureas are more commonly associated with the adverse event of hypoglycaemia. The symptoms associated with hypoglycaemia could be mistaken for an allergy by those not familiar with the nuances.

Non-steroidal anti-inflammatory drugs

Some clients can be sensitive to aspirin, ibuprofen, or other non-steroidal anti-inflammatory drugs (NSAIDs). Common symptoms include a stuffy nose, wheezing, and difficulty breathing. Some people may develop asthma.

Management and treatment

Medication allergies represent a significant and complex challenge within the healthcare system, affecting clients’ safety and treatment efficacy. Ultimately, a proactive approach involving clients, healthcare providers, and ongoing research is key to minimising the impact of medication allergies and improving outcomes for those affected.

Managing a medication allergy involves several strategies

Avoidance: The most effective way to prevent an allergic reaction is to avoid the offending drug.
Medical alert identification: Wearing a medical alert bracelet can inform healthcare providers about the allergy in emergencies.
Substitute medications: Finding alternative drugs that do not cause allergic reactions.
Desensitisation: In some cases, gradually introducing small doses of the drug can help the body tolerate it better. This is usually done in a controlled medical setting.
Emergency treatment: Clients with a history of severe reactions may be prescribed an epinephrine auto-injector (EpiPen) to use in case of anaphylaxis.

Prevention and client education

Awareness and education are key in preventing and managing medication allergies. You should encourage your clients to:

Communicate with their healthcare providers: Always inform doctors, nurses, and pharmacists about any known drug allergies.
Read medication labels: Be aware of the ingredients in both prescription and over-the-counter medications.
Keep records: Maintain a detailed list of all medications taken and any reactions experienced.

Conclusion

Medication allergies are a complex but manageable challenge in healthcare. With accurate diagnosis, thorough documentation, and ongoing education, health professionals can reduce risks and provide safer, more effective care.