Animals that are allergic to this drug or those with Addison’s disease should not be treated with Soloxine. Extreme caution is required while treating animals with high blood pressure. It can interact with certain drugs such as insulin, epinephrine, ketamine, warfarin, theophylline, digoxin, phenytoin and barbiturates. Hence, it is advisable to let the veterinarian know about any other medications that the pet is being treated with. Only those pets that are precisely diagnosed with hypothyroidism should be treated with Soloxine. Never administer Soloxine immediately after giving vitamin supplements or mineral combinations containing iron or calcium. The action mechanism of Soloxine might differ in different brands, so it is important to test the T4 levels, every time a brand is changed.