A client being treated for an allergy has been prescribed antihistamines. The Kardex of this client reads as follows: Age: 32; Profession: Carpenter; Lifestyle & diet: Lives alone, average smoker, nonalcoholic, no food preferences, practices yoga; Medical history: Suffers from hay fever, recent urinary tract infection that has been treated successfully. What information from the Kardex is likely to have the greatest implication in educating the client about antihistamine administration?