What happens when you’re allergic to drugs

Drugs that are a common source of allergies are anti-inflammatory medicines and antibiotics; however, any type of drug can result in an allergic reaction. — AZMAN GHANI/The Star

Have you ever had a rash and itchiness on your skin, swelling on your face, or difficulty of breathing, after eating something?

If so, you may have an allergy.

Allergies are a common condition where the immune system reacts abnormally to typically harmless substances.

Besides specific foods, individuals can also be allergic to a variety of other substances, such as animal fur, dust mites, pollen, fungus, chemicals and medicines.

However, not everyone has an allergy, and even among those who do have allergies, the allergens might not be the same from one individual to another.

Allergic reactions to medicines, also known as drug allergies, occur when the body’s immune system mistakenly identifies a medicine as a harmful foreign substance and releases histamines and other body chemicals to combat it.

Histamines are a compound that play a crucial role in the immune response.

Certain cells, like mast cells and basophils, will release histamines when the body detects the presence of an allergen.

The primary function of histamines is to help the body get rid of allergens by increasing the permeability of blood vessels, allowing immune cells to access affected tissues more easily.

However, this release of histamines can lead to various allergy symptoms, such as itchiness, swelling, hives and difficulty breathing.

This immune response can even lead to severe reactions like anaphylactic shock, which can be life-threatening.

Treating drug allergies

Drug allergies can generally be classified into two categories: mild and serious.

Mild allergy symptoms include skin rashes, itchiness, hives, localised swelling, sneezing and a runny nose.

These symptoms typically appear shortly after taking the medicine, but may resolve once the medicine is discontinued.

To manage these symptoms, medications like anti-histamines and corticosteroids can be effective.

Individuals experiencing mild allergies are advised to consult a doctor or pharmacist to determine the appropriate treatment options for their condition.

On the other hand, life-threatening allergic reactions manifest through more severe symptoms, such as rashes over the whole body, facial swelling, breathing difficulties or burns on the skin.

These conditions require immediate emergency treatment at a healthcare facility.

Admitting patients with serious allergic reactions to the hospital ensures immediate and intensive treatment, along with continuous monitoring for any potential complications.

The healthcare setting allows for the prompt management of severe symptoms and potential delayed reactions, providing comprehensive and life-saving care.

It is especially crucial for patients, or their accompanying family members or friends, to remember the name of the medicine that triggered the allergic reaction.

Examples of medicines commonly associated with allergies include anti-inflammatory medicines (e.g. diclofenac and mefenamic acid) and antibiotics (e.g. amoxicillin and sulphamethoxazole).

However, individuals may be allergic to other classes of medicines as well.

It is crucial for a person experiencing an allergic reaction to always remember the name of the medicine they are allergic to.

This is because a second exposure to the same medicine can trigger a more severe allergic reaction than the first.

The best way to identify the particular medicine is by remembering its generic name.

The generic name refers to the active ingredient, or the common name used worldwide, to denote a specific medicine.

In contrast, the brand name is the name given by the manufacturer to market the medicine.

A brand name might not be recognised in a certain region or country, therefore, remembering the generic name of the medicine is strongly advised.

Carry your card

When experiencing symptoms of an allergic reaction, seeking immediate medical attention at a healthcare facility is important.

Doctors will assess the patient’s condition and provide appropriate interventions based on the specific symptoms and severity of the allergy.

Prompt medical care can alleviate symptoms and prevent life-threatening reactions like anaphylactic shock.

It is vital for patients to bring along the medicines suspected of triggering the allergy when seeking medical help.

This enables the doctor to accurately identify the medicines and report the allergic reactions to the pharmacist.

Additionally, the doctor will be able to request the issuance of a drug allergy card.

This card will be issued to the individual by the pharmacist once there is solid evidence that a drug allergy has occurred.

Strong evidence is needed in order to ensure that only patients who genuinely suffer from drug allergies are given the allergy card.

This is essential to avoid treatment failure for other medical conditions, especially in critical situations where drug options are limited.

An allergy card is the easiest way to inform a healthcare professional about a patient’s drug allergies, thus enabling the doctor to choose suitable alternative treatments in any future medical encounters.

The card, issued by the Health Ministry, contains the cardholder’s name, the medicines that cause the allergy, and the name of the issuing health facility.

Carrying the allergy card is essential for patients during medical appointments, while receiving treatments, or while purchasing medicines at pharmacies.

It ensures that healthcare professionals are promptly notified of the patient’s allergies, thereby preventing potential allergic reactions.

Patients should keep this card with them at all times to help safeguard their health when getting medical treatment and during any emergency situations.

Patients should also bring any prescriptions, a list of current medicines, or information about previous medicines taken, to provide comprehensive information for the doctor or pharmacist.

Be proactive

In summary, understanding the mechanism of drug allergies and the appropriate steps to address them can empower individuals to take proactive measures in managing their allergies.

It is crucial for individuals on any medicines to recognise the symptoms of drug allergies and seek immediate medical attention when an allergic reaction occurs.

Additionally, knowing the name of the medicine you are allergic to, as well as carrying a drug allergy card, can help healthcare professionals avoid any allergic reactions and ensure safe treatment for you whenever necessary.

For any inquiries regarding medicines, please call the National Pharmacy Call Centre (NPCC) at the toll-free number 1-800-88-6722 during weekdays from 8am to 5pm, except on public holidays.

Ainur Fadlina Mohd Nadzir is a pharmacist at Hospital Sultan Idris Shah in Serdang, Selangor. This article is courtesy of the Health Ministry’s Pharmacy Practice and Development Division. For more information, email [e-mail]. The information provided is for educational and communication purposes only, and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this article. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.