758 APPENDIX B DRUG FORMULARY
Drug name (trade orother names)Pharmacology andindicationsAdverse effects andprecautionsDosing information andcommentsFormulationsDosage (unlessotherwise indicated,dose is the same fordogs and cat)Cetirizine (Zyrtec)Antihistamine (H1blocker). It acts byblocking the histaminetype-1 receptor (H1) andsuppressing inflammatoryreactions caused byhistamine. The H1blockers have been usedto control pruritus andskin inflammation,rhinorrhea, and airwayinflammation. Cetirizine isconsidered asecond-generationantihistamine, which maybe associated with lesssedation than older drugs.No adverse effects havebeen reported in dogs orcats.There are no studiespublished thatdemonstrate clinicalefficacy in dogs and cats.Clinical use is based onexperimental animals.1 mg/mL oral syrup;5 and 10 mg tablets.2.5–5 mg per animal,once daily po.Chlorambucil(Leukeran)Cytotoxic agent. Acts insimilar manner ascyclophosphamide asalkylating agent. Used fortreatment of varioustumors andimmunosuppressivetherapy.Myelosuppression ispossible. Cystitis does notoccur with chlorambucilas withcyclophosphamide.Consult anticancer drugprotocol for specificregimens.2 mg tablets.Dog: 2–6 mg/m2q24hinitially, then q48h po.Cat: 0.1–0.2 mg/kg q24hinitially, then q48h po.