Some medications do interfere with skin test results or cause potential medical complications. Fortunately, asthma medications do not. A patient should never abruptly stop taking any prescribed medications without first checking with their physician. In most cases, allergists advise discontinuing the following types of medications at least two to four days prior to allergy skin testing: over-the-counter (OTC) antihistamines and prescription non-sedating antihistamines (Benadryl, Chlor-Trimeton, Dimetapp, Tavist-1, Allegra, Claritin, Zyrtec), monoaminoxidase inhibitors (Nardil, Parnate) and tricyclic antidepressants (Elavil, Sinequan, Wellbutrin). Some medications should be stopped a week before testing.
Skin tests cannot be performed on patients who are taking beta-blockers (Inderal,Tenormin). However, as with any medication, patients should not discontinue medication unless directed and supervised by their physician.