Medications to Stop Before a Skin Prick Test for Accurate Allergy Diagnosis
A skin prick test is one of the most reliable ways to diagnose allergies, but did you know that certain medications can affect your results? If you’re scheduled for a test, it’s crucial to pause some medications beforehand to ensure accurate results.
Why Do Some Medications Affect Skin Prick Testing?
Skin prick testing works by introducing small amounts of allergens onto the skin to observe your body’s reaction. However, some medications—especially antihistamines—can suppress these reactions, leading to false-negative results. This means you could have an allergy but not see any reaction on the test.
Medications to Avoid Before Your Skin Prick Test
To get the most accurate results, stop taking the following medications before your test:
1. Antihistamines (Stop 5–7 Days Before)
Antihistamines block allergic reactions, making it harder to detect sensitivities during testing. These include:
X Oral antihistamines – Aerius, Atarax, Claritin, Clarinase, Piriton, Polaramine, Promethazine, Telfast, Xyzal, Zyrtec
X Cold & flu medications – Many over-the-counter sinus and flu tablets contain antihistamines (e.g., Panadol Cold & Flu)
X Allergy eye drops – Some eye drops used for allergies have antihistaminic properties and may need to be stopped (we generally ask patients not to take it on the am of the skin test)
2. Certain Antidepressants (Stop 2 Weeks Before, If Possible)
Some antidepressants have antihistaminic effects, which can interfere with skin testing. These include:
X Tricyclic antidepressants – Amitriptyline (Elavil), Doxepin (Sinequan), Imipramine (Tofranil)
If you are on these medications, consult your doctor before stopping them.
What Medications Can You Continue Taking?
Not all medications interfere with skin testing. You DO NOT need to stop:
✔ Asthma inhalers (including inhaled steroids and bronchodilators)
✔ Leukotriene inhibitors like Singulair or Accolate
✔ Oral theophylline (Theo-Dur, Uniphyl, Theo-24)
Why Didn’t We Tell You to Stop Your Medications Before Your Appointment?
If this is your first visit, we typically do not ask you to stop any medications before seeing an allergy specialist. Why? Because every patient is unique, and we need to assess your medical history first. Stopping certain medications without guidance could be unsafe.
During your consultation, your doctor will determine the best approach for testing and advise you on any necessary adjustments to your medications.
Get the Most Accurate Allergy Test Results
If you’re scheduled for a skin prick test, double-check your medications and pause any that could interfere. Not sure what to do? The Allergy Immunology Clinic Team is ready to help!
