Felimazole Tablets 2.5 mg (100 tablets)

Side effects of Felimazole Tablets 2.5 mg (100 tablets)

Do not use in cats suffering from systemic disease such as primary liver disease or diabetes mellitus.

Do not use in cats showing signs of autoimmune disease.

Do not use in animals with disorders of white blood cells, such as neutropenia and lymphopenia.

Do not use in animals with platelet disorders and coagulopathies (particularly thrombocytopenia).

Do not use in pregnant or lactating females.

Do not use in cats with hypersensitivity to thiamazole or the excipient, polyethylene glycol.

Adverse reactions: In a clinical field study approximately 20 % of the cats experienced some form of adverse reaction, most frequently when the product was used for long-term control of hyperthyroidism. In many cases symptoms may be mild and transitory and not a reason for withdrawal of treatment. The more serious effects are mainly reversible when medication is stopped.

At doses of 5-15 mg per cat per day the clinical side effects were vomiting, inappetance/anorexia, lethargy, severe pruritus and excoriations of the head and neck, bleeding diathesis and icterus associated with hepatopathy, and haematological abnormalities (eosinophilia, lymphocytosis, neutropenia, lymphopenia, slight leucopenia, agranulocytosis, thrombocytopenia or haemolytic anaemia). These side effects resolved within 7-45 days after cessation of thiamazole therapy.

Haematology must be monitored due to risk of leucopenia or haemolytic anaemia.

Any animal that suddenly appears unwell during therapy, particularly if they are febrile, should have a blood sample taken for routine haematology and biochemistry.

Neutropenic animals (neutrophil counts <2.5 x 109/l) should be treated with prophylactic bactericidal antibacterial drugs and supportive therapy.

Immunological side effects (anaemia, thrombocytopenia, serum anti-nuclear antibodies) can occur. Treatment should be stopped immediately and alternative therapy considered following a suitable period for recovery.

Following long-term treatment with thiamazole in rodents, an increased risk of neoplasia in the thyroid gland has been shown to occur, but no evidence is available in cats.

If you notice any serious effects or other effects not mentioned in the data sheet, please inform your veterinary surgeon.

Special precautions for use in animals: As thiamazole can cause haemoconcentration, cats should always have access to drinking water.

Tell your veterinary surgeon if your cat has any known renal problems.

Use of the product in cats with renal dysfunction should be subject to careful risk:benefit assessment by the clinician.

Due to the effect thiamazole can have on reducing the glomerular filtration rate, the effect of therapy on renal function should be monitored closely as deterioration of an underlying condition may occur.

Special precautions to be taken by the person administering the veterinary medicinal product to animals: Wash hands after use.

In the case of accidental ingestion, seek medical advice immediately and show the data sheet to the physician.

Thiamazole may cause vomiting, epigastric distress, headache, fever, arthralgia, pruritus and pancytopenia. Treatment is symptomatic.

Wash hands with soap and water after handling litter used by treated animals.

Do not eat, drink or smoke while handling the tablet or used litter.

Do not handle this product if you are allergic to hyperthyroidism inhibitors.

Do not break or crush tablets.

As thiamazole is a suspected human teratogen, women of child-bearing age should wear gloves when handling litter of treated cats.

Use during pregnancy, lactation or lay: Laboratory studies in rats and mice have shown evidence of teratogenic and embryotoxic effects of thiamazole. The safety of the product was not assessed in pregnant or lactating cats. Do not use in pregnant or lactating females.

Interaction with other medicinal products and other forms of interaction: If your cat is being treated with any other medications advise your veterinary surgeon prior to the use of Felimazole.

Concurrent treatment with phenobarbital may reduce the clinical efficacy of thiamazole.

Thiamazole is known to reduce the metabolism of benzimidazole wormers and may lead to increases in their plasma concentrations when given concurrently.

Thiamazole is immunomodulatory therefore this should be taken into account when considering vaccination programmes.

Overdose: In tolerance studies in young healthy cats, the following dose-related clinical signs occurred at doses of up to 30 mg/animal/day: anorexia, vomiting, lethargy, pruritus and haematological and biochemical abnormalities such as neutropenia, lymphopenia, reduced serum potassium and phosphorous levels, increased magnesium and creatine levels and the occurrence of anti-nuclear antibodies. At a dose of 30 mg/day some cats showed signs of haemolytic anaemia and severe clinical deterioration. Some of these signs may also occur in hyperthyroid cats treated at doses of up to 20 mg per day.

Excessive doses in hyperthyroid cats may result in signs of hypothyroidism. This is however unlikely, as hypothyroidism is usually corrected by negative feedback mechanisms.

Please refer to Adverse Reactions section.

If overdosage occurs, stop treatment and immediately contact your veterinary surgeon.

General precautions: For animal treatment only.