Information about Thyronorm 50mcg Tablet
- Product Composition:
- Thyroxine/Levothyroxine Sodium
- Precautions:
- Patients w/ CV (e.g. angina, heart failure, HTN), DM and diabetes insipidus, epilepsy, pre-existing myasthenia syndrome, long-standing hypothyroidism. Elderly, pregnancy and lactation. Monitoring Parameters Monitor thyroid function test, clinical signs of hypo- and hyperthyroidism, heart rate and BP. Lactation: Enters breast milk; use caution
- Indications:
- Hypothyroidism, TSH suppression, Myxoedema coma
- Contraindications:
- Untreated hyperthyroidism; uncorrected adrenal failure; recent MI.
- Dosage:
- Adult: PO Hypothyroidism Inital: 50-100 mcg/day. Maintenance: 100-200 mcg/day. Severe and chronic hypothyroidism Initial: 12.5-25 mcg/day, increase gradually if needed. TSH supression For thyrotropin-dependent well-differentiated thyroid cancer: Doses >2 mcg/kg/day may be used to achieve TSH target of <0.1 MIU/L. For benign nodules and nontoxic multinodular goitre: Target TSH suppresion to 0.1-0.5 MIU/L for nodules and 0.5-1.0 MIU/L for multinodular goitre.
- Common Side Effects:
- Nervousness, excitability, tremor, muscle weakness, fatigue, cramps; sweating, flushing, heat intolerance, headache, fever, insomnia, tachycardia, palpitations, restlessness, anginal pain, HTN, severe depression, difficulty in sleeping, excessive wt loss; menstrual irregularities; diarrhoea, vomiting, psychosis or agitation. Increased bone resorption and reduced bone mineral density, especially in post-menopausal women; elevated LFT. Potentially Fatal: Thyrotoxic crisis including convulsions, cardiac arrhythmia, heart failure, coma.
- Mode Of Action:
- Levothyroxine Na is a synthetic form of thyroxine which increases the basal metabolic rate (BMR) and the utilisation and mobilisation of glycogen stores and stimulates protein synthesis. It is also involved in normal metabolism, growth and development. These effects are mediated at the cellular level by the thyroxine metabolite, tri-iodothyronine.
- Interaction:
- Reduced absorption w/ iron, antacids, bile acid sequestrants, colestyramine, simeticone, Ca carbonate, sucralfate, cation exchange resins. Reduced tri-iodothyronine serum levels w/ amiodarone and propranolol. Reduced serum levels of thyroxine w/ carbamazepine, phenytoin, phenobarbital, rifampicin, lithium, oestrogens, sertraline. Androgens may decrease levothyroxine-binding globulins serum levels. May alter requirements of antidiabetic drugs. Increased risk of significant HTN and tachycardia w/ ketamine. Increased metabolic demands w/ sympathomimetics (e.g. epinephrine). May increase anticoagulant effect of warfarin.
- Pregnancy Interaction:
- Pregnancy Category - A Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
- Therapeutic Class:
- Thyroid drugs & hormones
