NEOMERCAZOLE

NeoMercazole should only be administered if hyperthyroidism has been confirmed by laboratory tests. Posology Adults The initial dose is in the range 20 mg to 60 mg, taken as two to three divided doses. The dose should be titrated against thyroid function until the patient is euthyroid in order to reduce the risk of over-treatment and resultant hypothyroidism.

Subsequent therapy may then be administered in one of two ways.

Maintenance regimen:

Final dosage is usually in the range 5 mg to 15 mg per day, which may be taken as a single daily dose. Therapy should be continued for at least six months and up to 18 months. Serial thyroid function monitoring is recommended, together with appropriate dosage modification in order to maintain a euthyroid state.

e. 20 mg to 60 mg per day, and supplemental L-thyroxine, 50 mcg to 150 mcg per day, is administered concomitantly, in order to prevent hypothyroidism. Therapy should be continued for at least six months and up to 18 months. Where a single dosage of less than 20 mg is recommended, it is intended that carbimazole 5 mg tablets should be taken.

Elderly No special dosage regimen is required, but care should be taken to observe the contraindications and warnings as it has been reported that the risk of a fatal outcome to neutrophil dyscrasia may be greater in the elderly (aged 65 or over).

Paediatric population Use in children and adolescents (3 to 17 years of age) The usual initial daily dose is 15 mg per day adjusted according to response. Use in children (2 years of age and under) Safety and efficacy of carbimazole in children below 2 years of age have not been evaluated systematically.

Use of carbimazole in children below 2 years of age is therefore not recommended. Method of administration Oral

Adverse reactions usually occur in the first eight weeks of treatment. The most frequently occurring reactions are nausea, headache, arthralgia, mild gastric distress, skin rashes and pruritus. These reactions are usually self-limiting and may not require withdrawal of the drug.

The undesirable effects are listed below by system organ class and the following frequency convention: Not known (cannot be estimated from the available data). Blood and lymphatic system disorders Bone marrow depression including neutropenia, eosinophilia, leucopenia and agranulocytosis has been reported.

Fatalities with carbimazole-induced agranulocytosis have been reported. Rare cases of pancytopenia/aplastic anaemia and isolated thrombocytopenia have also been reported. Additionally, very rare cases of haemolytic anaemia have been reported.

Patients should always be warned about the onset of sore throats, bruising or bleeding, mouth ulcers, fever and malaise and should be instructed to stop the drug and to seek medical advice immediately. In such patients, white blood cell counts should be performed immediately, particularly where there is any clinical evidence of infection.

Generalised lymphadenopathy. Immune system disorders Angioedema and multi-system hypersensitivity reactions such as cutaneous vasculitis, liver, lung and renal effects occur. Endocrine disorders Insulin autoimmune syndrome (with pronounced decline in blood glucose level).

Nervous system disorders Headache, neuritis, polyneuropathy. Vascular disorders Bleeding. Gastrointestinal disorders Nausea, mild gastrointestinal disturbance. Loss of sense of taste has been observed. Acute salivary gland swelling Acute pancreatitis.

Hepatobiliary disorders Hepatic disorders, including abnormal liver function tests, hepatitis, cholestatic hepatitis, cholestatic jaundice and most commonly jaundice, have been reported; in these cases carbimazole tablets should be withdrawn.

Bone marrow depression including neutropenia, eosinophilia, leucopenia and agranulocytosis has been reported. Fatalities with carbimazole-induced agranulocytosis have been reported. Rare cases of pancytopenia/aplastic anaemia and isolated thrombocytopenia have also been reported.

Additionally, very rare cases of haemolytic anaemia have been reported. Patients should always be warned about the onset of sore throats, bruising or bleeding, mouth ulcers, fever and malaise and should be instructed to stop the drug and to seek medical advice immediately.

In such patients, white blood cell counts should be performed immediately, particularly where there is any clinical evidence of infection. Following the onset of any signs and symptoms of hepatic disorder (pain in the upper abdomen, anorexia, general pruritus) in patients, the drug should be stopped and liver function tests performed immediately.

Early withdrawal of the drug will increase the chance of complete recovery. NeoMercazole should be used with caution in patients with mild-moderate hepatic insufficiency. If abnormal liver function is discovered, the treatment should be stopped.

The half-life may be prolonged due to the liver disorder. NeoMercazole should be stopped temporarily at the time of administration of radio- iodine (to avoid thyroid crisis). Patients unable to comply with the instructions for use or who cannot be monitored regularly should not be treated with NeoMercazole.

Regular full blood count checks should be carried out in patients who may be confused or have a poor memory. Precaution should be taken in patients with intrathoracic goitre, which may worsen during initial treatment with NeoMercazole.

Tracheal obstruction may occur due to intrathoracic goitre. 6). There is a risk of cross-allergy between carbimazole, the active metabolite thiamazole (methimazole) and propylthiouracil. There have been post-marketing reports of acute pancreatitis in patients receiving carbimazole or its active metabolite thiamazole.

1. • Serious, pre-existing haematological conditions, • Severe hepatic insufficiency. • Patients with a history of acute pancreatitis after administration of carbimazole or its active metabolite thiamazole.