It is advised not to use the medication in animals with liver disease, clotting problems and those allergic to medications of this genre. The drug is not recommended for use in pregnant or nursing animals. The medication should not be used within 2 hours of an antacid and with cisapride, astemizole or terfenadine. Extreme caution is required when used with phenobarbital, cyclosporine, theophylline, phenytoin, and anticoagulants such as warfarin. Make sure to inform the veterinarian or pharmacist about the medications the pet is taking. Administering the medication with food could reduce the side effects. Store the medication at room temperature, away from excess heat, light and moisture.