What is CYTOMEL?

CYTOMEL 5 MCG contains LIOTHYRONINE (LIOTHYRONINE SODIUM) 5 MCG. It is listed in the Health Canada Drug Product Database under DIN 01919458, held by PFIZER CANADA ULC, supplied as Tablet for Oral administration. Health Canada currently lists it as marketed, status dated 20-Mar-2013. Nexara Health is a licensed Canadian wholesale distributor (DEL 3-002896-A) and can source this product for hospitals, pharmacies and clinics. Availability and lead time are confirmed per order.

What is CYTOMEL used for?

Cytomel® is indicated in conditions of inadequate endogenous thyroid production. These include: a. HYPOTHYROIDISM: As replacement or supplemental therapy in patients with hypothyroidism of any etiology except transient hypothyroidism during the recovery phase of subacute thyroiditis b. SIMPLE (non-toxic) GOITER: Cytomel® may be tried therapeutically in an attempt to reduce the size of such a goiter, the rationale being that suppression of pituitary thyroid stimulating hormone (TSH) removes at least one of the growth-promoting factors. Cytomel® may be used in the T3 suppression test to differentiate suspected hyperthyroidism from euthyroidism. (See special instructions under ADMINISTRATION AND DOSAGE). Cytomel® can be used in patients allergic to dessicated thyroid or thyroid extract derived from pork or beef.

Authorized indication as written in the Health Canada product monograph. For healthcare professionals and licensed purchasers; this is not medical advice.

Product details and regulatory record

How is it administered?

Dosing Considerations: Optimum dosage is usually determined by the patient's clinical response. Confirmatory tests include: Radioactive Iodine T3 Resin Uptake, 131I-T3 Red cell Uptake, BMR, and the Achilles Tendon Reflex Test. Comparatively small doses (as little as 5 µg daily) may be fully effective in some cases; however, in other instances, a satisfactory clinical response may not be achieved until recommended dosage levels have been exceeded. Daily doses of up to 150 µg may be required in a few resistant patients. Recommended Dose and Dosage Adjustment: It is not necessary to divide daily maintenance doses. Although Cytomel® has a rapid cut-off, its metabolic effects persist for a few days following discontinuance. Mild Hypothyroidism: Recommended starting dose is 25 µg daily. Daily dosage then may be increased by 12.5 or 25 µg every one or two weeks. Usual maintenance dosage is 25 – 75 µg daily. Smaller doses may be fully effective in some patients, while 100 µg may be required in others. Myxedema: Myxedematous patients are very sensitive to thyroid substances; dosage should be started at a very low level and increased gradually. Recommended starting dosage is 5 µg daily. This may be increased by 5 or 10 µg daily every one or two weeks. Usual maintenance dosage is 50 to 100 µg daily. Cretinism: Since the mother provides little or no thyroid hormone to the fetus, infants with thyroid dysfunction will require replacement therapy from birth. Treatment should be initiated as early as possible to avoid permanent physical and mental changes. Recommended starting dosage is 5 µg daily, with a 5 µg increment every three to four days until the desired response is achieved. Infants a few months old may require only 20 µg daily for maintenance. At one year, 50 µg daily may be required. Above 3 years, full adult dosage may be necessary. Simple (non-toxic) Goiter: recommended starting dosage is 5 µg daily. This dosage may be increased by 5 to 10 µg daily every one to two weeks. When 25 µg daily is reached, dosage may be increased every week or two by 12.5 or 25 µg. Usual maintenance dosage is 75 µg daily. Special Populations Pediatrics: Treatment should be initiated immediately upon diagnosis and maintained for life, unless transient hypothyroidism is suspected, in which case, therapy may be interrupted for 2 to 8 weeks after the age of 3 years to reassess the condition. Gradual cessation of therapy is justified in patients who have maintained a normal TSH during those 2 to 8 weeks. Therapy should be started with 5 µg daily and increased only by 5 µg increments at the recommended intervals. See WARNINGS and PRECAUTIONS. Geriatrics: Therapy should be started with 5 µg daily and increased only by 5 µg increments at the recommended intervals. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. See WARNINGS and PRECAUTIONS. Switching to Cytomel® from thyroid, L-thyroxine or thyroglobulin medication: When switching a patient to Cytomel® from thyroid, L-thyroxine or thyroglobulin, discontinue the other medication, initiate Cytomel® at a low dosage, and increase gradually according to the patient's response. When selecting a starting dose, bear in mind that this drug has a rapid onset of action, and that residual effects of the other thyroid preparation may persist for the first several weeks of therapy. Special Instruction for T3 Suppression Test: When 131I thyroid uptake is in the borderline-high range, administer 75-100 of Cytomel® daily for 7 days, then repeat 131I thyroid uptake test. In the hyperthyroid patient, 24-hour 131I thyroid uptake will not be affected significantly. In the euthyroid patient, 24-hour 131I thyroid uptake will drop to less than 20%.

Included because it drives pack selection and wastage. Consult the monograph.

How is it stored and handled?

Store at room temperature (15-25°C or 59-77°F), away from heat, light and moisture. Keep container firmly closed and away from the reach of children.

How is it supplied?

Bottles of 100. 5µg: Round white to off-white flat face beveled-edge tablet, debossed KPI on one side and 115 on the other. 25µg: Round white to off-white flat face beveled-edge tablet, debossed KPI 116 on one side and a single bisect on the other.

Contraindications

• Patients with an apparent hypersensitivity to liothyronine sodium or any of the inactive product constituents. • Patients with uncorrected adrenal insufficiency, as thyroid hormones increase tissue demands for adrenocortical hormones and may thereby precipitate acute adrenal crisis (see WARNINGS AND PRECAUTIONS). • Patients with acute myocardial infarction

Warnings and precautions

Serious Warnings and Precautions The use of Cytomel® or other thyroid preparations in the therapy of obesity is unjustified and dangerous. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for anorectic effects. General Cytomel® has a narrow therapeutic index and has a relatively short half-life compared to levothyroxine. Regardless of the indication for use, careful dosage titration is necessary to avoid the consequences of over or under treatment. These consequences include, among others, effects on growth and development, cardiovascular function, bone metabolism, reproductive function, emotional state and gastrointestinal function. Many drugs interact with liothyronine sodium, necessitating adjustments in dosing to maintain therapeutic response (See DRUG INTERACTIONS). Cardiovascular Since Cytomel® is a metabolic stimulant, it is not recommended for use in patients with compromised cardiovascular systems, particularly the coronary arteries. These include patients with angina pectoris, ischemic states, and the elderly (in whom there is a greater likelihood of occult cardiac disease). However, if it is used in such patients, caution should be exercised and the starting dosage should never be more than 5 µg daily. If the dosage is increased, it should be in increments of no more than 5 µg daily at two-week intervals. (See DOSAGE and ADMINISTRATION).

What can be used instead?

Other Canadian products sharing ATC code H03AA02 LIOTHYRONINE SODIUM. 6 of 6 DINs in this group are currently marketed — marketed products are listed first, because that is what can actually be bought. These tables describe supply, not clinical equivalence: substitution rests with the prescriber or pharmacist, and interchangeability is determined provincially.

Who else supplies LIOTHYRONINE SODIUM worldwide?

Nexara tracks national medicine registries and published price lists across multiple markets. LIOTHYRONINE SODIUM appears in 10 registered pack listings across 4 markets, published on 4 different national price bases. Where a Canadian route is closed, that is where an alternative route of supply starts — subject to the import rules in both countries.

Registered listings are not stock. Ask us to confirm what can actually be sourced for your order.