MedlinePlus: Cetirizine - Provides information on usage, precautions, side effects and brand names when available. Data provided by various government agencies and health-related organizations. - http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a698026.html
Zyrtec - US product prescribing information from Pfizer. (Requires Adobe Acrobat reader) - http://www.pfizer.com/pfizer/download/uspi_zyrtec.pdf
DrugDigest: Cetirizine ( Zyrtec ) - Information on dosage, usage, side effects, interactions, and drug comparisons. - http://www.drugdigest.org/DD/DVH/Uses/0,3915,133%7CCetirizine%2BHydrochloride,00.html