Bitiron (Thyroxine sodium [T4]/Liothyronine sodium [T3] 50mcg/12.5mcg) Tablets

Bitiron contains synthetically manufactured levothyroxine sodium (T4) 50mcg and liothyronine sodium (T3) 12.5mg in a 4:1 ratio. Bitiron is used to treat conditions where the body manufactures insufficient quantities of thyroid hormones leading to a condition known as hypothyroidism.

Bitiron tablets are used in the management of severe chronic thyroid deficiency or hypothyroidism in which the thyroid gland does not make enough thyroid hormone needed to regulate the body’s growth and metabolism.  This may be due to underactive thyroid, or as a result of an autoimmune disease (where the immune system is directed against self) called Hashimoto’s thyroiditis; or because the pituitary gland does not produce enough thyroid stimulating hormone. 

Bitiron tablets are used to help to relieve the symptoms of hypothyroidism (also known as myxoedema), including tiredness, muscle weakness, cramps, feeling the cold, a slow heart rate, dry and flaky skin, hair loss, a deep husky voice and weight gain; also, myxoedema coma, which is a serious complication of hypothyroidism.  

Bitiron tablets are also used treat or prevent thyroid goitre, in which the thyroid becomes enlarged to compensate for low levels of thyroid hormone and is often due to iodine deficiency.   Bitiron tablets are also used to increase low thyroxine levels (in addition to another drug called carbimazole), which may result from treatment for thyrotoxicosis or overactive thyroid gland, in which overproduction of thyroid hormones is the result of autoimmune disease (Graves’ disease) or inflammation of the thyroid gland.  Bitiron tablets can be used in patients allergic to desiccated thyroid or thyroid extract derived from pigs or cows.

Bitiron tablets contain levothyroxine (also known as T₄₎ and liothyronine (also known as triiodothyronine or T₃), both synthetically derived forms of naturally occurring (endogenous) thyroid hormone.  The major effect of exogenous thyroid hormones is to increase the metabolic rate of body tissues.  The thyroid gland produces mainly thyroxine (levothyroxine or T₄) and a small amount of liothyronine, however, the major form of thyroid hormone in the blood is T₄ which circulates bound to protein and is therefore not active.  When it reaches the target tissue, T₄ is released and converted to T₃ which is 3-4 times more potent than T₄ and acts rapidly by interacting with a specific receptor inside cells to stimulate proteins needed to manage and regulate a variety of processes, including how the body regulates temperature, metabolises nutrients and controls growth and development. 

Bitiron contains synthetically manufactured levothyroxine sodium (T4) 50mcg and liothyronine sodium (T3) 12.5mg in a 4:1 ratio. Bitiron also contains the following inactive ingredients: Lactose (from bovine milk), Starch, PVP K-30, Alcohol and Magnesium stearate.

Most of the side effects experienced with taking Bitiron tablets indicate that the dose is too high and may need adjusting.  These include headache, palpitations, sleep problems (insomnia), feeling nervous or irritable sweating, flushing, appetite changes, weight loss, muscle weakness/cramps, tremors.  

You should not use Bitiron tablets if you:

• are allergic to Levothyroxine, Liothyronine or any ingredients in Bitiron sodium tablets
• are looking for a treatment for obesity or to help you lose weight; this is not a weight loss product
• are pregnant, planning to become pregnant or breast-feeding
• have a history of chest pain, heart attack, heart blood vessel problems, or other heart problems, particularly in the elderly
• have adrenal gland problems
• are a diabetic taking antidiabetics or insulin, without discussion with your doctor, as Bitiron tablets may affect your glucose tolerance
• are taking other medications that may interact with Bitiron tablets, including anticonvulsants like phenytoin and carbamazepine, cardiac glycosides like digoxin, cholesterol-lowing drugs containing cholestyramine, tricyclic antidepressants like amitriptyline, anticoagulants like warfarin, oral contraceptives containing oestrogen, insulin or oral hypoglycaemic for diabetes

Several medications interact with Bitiron tablets and should either not be taken while you are taking Bitiron or only after discussion and instruction from your doctor:

• Drugs that cause a serious reaction with Bitiron: tricyclic antidepressants like amitriptyline, anticoagulants like warfarin, cardiac glycosides like digoxin
• Drugs that affect Bitiron: cholesterol-lowing drugs containing cholestyramine, anticonvulsants like phenytoin and carbamazepine, oral contraceptives containing oestrogen
• Drugs that are affected by Bitiron: insulin or oral hypoglycaemic for diabetes
• Amezinium
• Amiodarone
• Bile acid sequestrants
• Calcium salts and calcium polystyrene sulfonate
• Ciprofloxacin
• Furosemide
• SSRI medications

You should take your Bitiron tablets with a glass of water with or without food.  The dose you take and how often depends on your condition and should be as recommended by your doctor. Usually one tablet daily is sufficient for most people but higher or lower dose adjustments may be necessary.

You may need to take your Bitiron tablets for a few weeks before you see an improvement and you should continue to take your Bitiron tablets for as long as recommended by your doctor, which may be for life.

You may need to take your Bitiron tablets for a few weeks before you see an improvement and you should continue to take your Bitiron tablets for as long as recommended by your doctor, which may be for life. The dose you take will be as recommended by your doctor and your thyroid levels should be monitored on a regular basis.

If you miss a dose of Bitiron tablets take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose.  Do not take a double dose.

You should store your Bitiron tablets below 25°C in a cool dry place.