Felanorm^®

Felanorm is available at 5 mg/mL in bottles containing 30 or 100 mL with 1 mL dosing syringe. 

Felanorm (methimazole) is indicated for the treatment of hyperthyroidism in cats

Always include the Instructions for Preparing a Dose of Felanorm (methimazole) Oral Solution and the Information for Cat Owners with a prescription. The starting dose of Felanorm is 2.5 mg administered every 12 hours. Following 3 weeks of treatment, the dose should be titrated to effect based on individual serum total T4 (TT4) levels and clinical response. Dose adjustments should be made in 2.5 mg increments. The maximum total dosage is 20 mg per day divided, not to exceed 10 mg as a single administration. Hematology, biochemistry, and TT4 should be evaluated prior to initiating treatment and monitored after 3 weeks and 6 weeks of treatment. Thereafter, bloodwork should be monitored every 3 months and the dose adjusted as necessary. Cats receiving doses greater than 10 mg per day should be monitored more frequently. The product should be administered orally using the enclosed graduated dosing syringe. The syringe has measurements representing the mg dose of the product. Rinse/clean the oral dosing syringe between uses. (See the Instructions for Preparing a Dose of Felanorm (methimazole) Oral Solution).

Store at controlled room temperature 25°C (77°F) with excursions between 15°-30°C (59°-86°F) permitted. Keep the container tightly closed. 

The drug most commonly used to manage this disease in the U.S. is methimazole. It is currently available as a human generic tablet, a veterinary-approved tablet (Felimazole^® Coated Tablets [methimazole tablets]), compounded oral and transdermal gel formulations and now the first FDA-approved oral solution, Felanorm^® (methimazole) Oral Solution.

Felanorm is the first FDA-approved oral solution that is indicated for the medical management of cats with hyperthyroidism. Because it is a honey-flavored oral liquid that is easy to give, it eliminates the struggle associated with trying to “pill” cats. The oral solution also avoids some of the increased health and safety hazards that are associated with exposure to transdermal gels for cat owners and other pets in the household.

As with all drugs, side effects may occur. The most commonly reported side effects are anorexia, vomiting, head/facial pruritus or edema, depression/lethargy, weight loss, anemia, elevated liver enzymes, skin lesions, elevated BUN, diarrhea and thrombocytopenia. Felanorm® Oral Solution is not for use in pregnant or lactating queens, or cats with renal, hepatic or hematological disorders. In some reported cases, the patients recovered after adverse signs were recognized, the drug was withdrawn and veterinary care was applied. In some cases, death (or euthanasia) has been reported as an outcome of the adverse reactions listed above. Methimazole has anti-vitamin K activity and may induce bleeding diathesis without evidence of thrombocytopenia. Please refer to the product insert for a complete list of warnings, potential side effects and prescribing information associated with Felanorm. To report suspected adverse drug events, for technical assistance or to obtain a copy of the Safety Data Sheet (SDS), contact Norbrook at 1-866-591-5777.

For additional information about adverse drug experience reporting for animal drugs, contact the FDA at 1-888-FDA-VETS or http://www.fda.gov/reportanimalae.

This product is not for use in humans. Keep out of reach of children. For use in cats only. Wear protective single use, impermeable (e.g., latex or nitrile) gloves when administering the solution. Wash hands with soap and water after administration to avoid exposure to drug. Wear protective gloves to prevent direct contact with litter, feces, urine or vomit of treated cats, and the solution. Wash hands after contact with the litter of treated cats.

Methimazole is a human teratogen and crosses the placenta, concentrating in the fetal thyroid gland. There is also a high rate of transfer into breast milk. Pregnant women, or women who may become pregnant, and nursing mothers should wear gloves when handling the solution, litter or bodily fluids of treated cats. Individuals with an endocrine disorder that could be impacted by methimazole should use similar precautions. Methimazole may cause vomiting, gastric distress, headache, fever, arthralgia, pruritus, and pancytopenia. In the event of accidental ingestion/overdose, seek medical advice immediately and show the product label to the physician. Avoid skin and oral exposure, including hand-to-mouth contact. Wash any spillages or splatter from the skin immediately. Do not eat, drink, smoke/vape or use smokeless tobacco while handling the product or used litter. Felanorm may cause skin or eye irritation. Avoid eye contact, including hand-to eye contact. In case of accidental eye contact, rinse eyes immediately with clean running water. If irritation develops, seek medical advice. Please refer to the product insert for a complete list of warnings, potential side effects and prescribing information associated with Felanorm.