Strumazol

Strumazol

thiamazole

Manufacturer:

Aspen

Distributor:

Zuellig
Full Prescribing Info
Contents
Thiamazole.
Action
Pharmacologic Category: Sulfur containing imidazole derivative.
Strumazol reduces synthesis of the thyroid hormones by inhibiting the incorporation of iodide in the thyroglobulins of the thyroid gland.
Pharmacokinetics: Strumazol is well absorbed. Maximum plasma concentrations are reached 1-2 hrs after oral administration.
After taking Strumazol 30 mg, a peak value of approximately 0.5 mcg/mL is obtained. The plasma t½ is 2-6 hrs and this is unchanged in hyperthyroidism. Strumazol is concentrated in the thyroid gland immediately after absorption. The Cmax in the thyroid gland is reached after 1 hr. The concentration in the thyroid gland varies from 1-10 mmol depending on the dose and the time after administration. The t½ in the thyroid gland is more prolonged and important than the plasma t½. After 20 hrs, the concentration in the thyroid gland is still almost the same as that after 6 hrs. The incorporation of iodide is inhibited for 24 hrs by taking 10-30 mg Strumazol. This means that Strumazol can usually be given once a day.
Indications/Uses
Mild to severe hyperthyroidism, treatment of Graves' disease, preparation of hyperthyroid patients for thyroidectomy and as an adjunct to radioactive iodine therapy.
Dosage/Direction for Use
Initial Dose: 15-60 mg daily. It is usually given in 3 divided doses but single daily dose is also possible. Improvement is usually seen in 1-3 weeks and control of symptoms is 1-2 months.
Euthyroid Patient: Dose is gradually reduced to a maintenance dose, usually 5-15 mg daily. Alternatively, the dose may be continued at the initial level with supplemental levothyroxine as a blocking-replacement regimen either form of maintenance treatment usually continued for 1-2 years.
Children: Initial Dose: 400 mcg/kg in divided doses; for maintenance this dose may be halved.
Overdosage
There is hardly any data available about overdosage. In an overdose, reduced thyroid hormone synthesis and possibly 1 or more of the side effects mentioned as follows can be expected.
Contraindications
Known hypersensitivity to thiamazole or carbimazole.
Mild forms can be treated with propylthiouracil but consideration must be given to the fact that cross-hypersensitivity reactions can frequently occur (in almost 50% of patients).
Agranulocytosis during previous treatment with thiamazole, carbimazole or propylthiouracil (in connection with the cross-hypersensitivity).
Special Precautions
At the beginning of the treatment, the patient must be clearly informed of the possible side effects (see Side Effects).
Use in pregnancy: From observations in man, it has become apparent that thiamazole can be harmful to the fetus. In particular, there have been a number of reports of the appearance of aplasia cutis of the skull. The evidence of teratogenicity is as yet, too weak to contraindicate use during pregnancy. Strumazol should only be used in pregnancy upon consultation with a specialist.
In prescribing anti-thyroids, it must be borne in mind that all thyroid depressants cross the placenta and therefore can lead to hypothyroidism and goiter formation in the fetus. In Graves' disease, one must also be prepared for the onset of hyperthyroidism in the fetus and thus, it would be advisable to treat the patient on anti-thyroid.
Use in lactation: The use of the standard dose of Strumazol leads to significant quantities of thiamazole in the mother's milk. Propylthiouracil is then preferable. Strumazol should only be used during lactation in consultation with a specialist.
Use In Pregnancy & Lactation
Use in pregnancy: From observations in man, it has become apparent that thiamazole can be harmful to the fetus. In particular, there have been a number of reports of the appearance of aplasia cutis of the skull. The evidence of teratogenicity is as yet, too weak to contraindicate use during pregnancy. Strumazol should only be used in pregnancy upon consultation with a specialist.
In prescribing anti-thyroids, it must be borne in mind that all thyroid depressants cross the placenta and therefore can lead to hypothyroidism and goiter formation in the fetus. In Graves' disease, one must also be prepared for the onset of hyperthyroidism in the fetus and thus, it would be advisable to treat the patient on anti-thyroid.
Use in lactation: The use of the standard dose of Strumazol leads to significant quantities of thiamazole in the mother's milk. Propylthiouracil is then preferable. Strumazol should only be used during lactation in consultation with a specialist.
Side Effects
The most common minor adverse effects are nausea, vomiting, gastric discomfort, headache, hair loss has also been reported. Bone marrow depression may occur. Full blood counts should be performed. These side effects are usually benign and generally of short duration and occur in approximately 5% of users. In most cases, there is no reason to stop the medication. The signs which may occur, particularly at high doses of Strumazol, are fever, arthralgia, arthritis and rashes (eg, urticaria). Mild rashes usually disappear despite continuation of treatment.
The blood frequently exhibits (transient) leukopenia (<4 x 10/L) which is mostly symptom-free. The frequency is thought to be approximately 10-20% in which it should be noted that mild forms of Graves' disease can also be accompanied by leukopenia. If the number of granulocytes is <1 x 10/L, treatment with Strumazol should be discontinued.
The serious side effect of agranulocytosis is usually characterized by general symptoms eg, fever and bacterial infection. These phenomena are usually acute and often occur within 2-3 months of starting treatment with Strumazol. Patients should be instructed to watch out for and report to their physicians, the occurrence of signs and symptoms eg, fever, sore throat and nose bleeding. Another serious side effect which is sometimes observed is hepatotoxicity, manifesting itself in cholestatic jaundice without liver cell necrosis.
Another rare complication is the occurrence of vasculitis or lupus erythematosus (LE) syndrome. Side effects which very rarely occur are aplastic anemia, thrombocytopenia, nephrotic syndrome and a loss of the sense of taste. Naturally, if Strumazol is administered as monotherapy, it can lead to primary hypothyroidism. After a reduction in thyroid function, Strumazol can also lead to enlargement of the thyroid gland with mechanical difficulties as a possible ultimate complication.
Drug Interactions
As Strumazol leads to a change in the metabolism, it may be necessary to adjust dosage of other drugs.
Storage
Store protected from light and moisture at temperatures not exceeding 25°C.
MIMS Class
ATC Classification
H03BB02 - thiamazole ; Belongs to the class of sulfur-containing imidazole derivative agents. Used in the management of thyroid diseases.
Presentation/Packing
Tab 10 mg x 100's. 30 mg x 30's.
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Sign up for free
Already a member? Sign in