Table 1.

Guidelines for discontinuation of medications that might interfere with interpretation of OFC

Medication	Last dose before OFC
Oral antihistamines	3-10d
Cetirizine	5-7d
Loratadine	7d
Oral H2 receptor antagonist	12 h
Oral long-acting β2-agonist	24 h
Theophylline (liquid)	24 h
Leukotriene antagonist	24 h
Oral/intramuscular/intravenous steroids	3d-2wk