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liotrix (Rx)Brand and Other Names:Thyrolar

 
 
 

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

Each 60 mg tablet will replace approximately 60-65 mg (1 grain) of desicated thyroid

Liothyronine sodium (T3) is approximately 4 times as potent as levothyroxine (T4)

tablet, T3/T4

  • Thyrolar 1/4 (15mg): 3.1/12.5mcg
  • Thyrolar 1/2 (30mg): 6.25/25mcg
  • Thyrolar 1 (60mg): 12.5/50mcg
  • Thyrolar 2 (120mg): 25/100mcg
  • Thyrolar 3 (180mg): 37.5/150mcg
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Hypothyroidism

1 tab of Thyrolar 1/2 daily; follow with increments of 1 tab of Thyrolar 1/4 q2-3wk

Lower starting dose of 1 tab recommended in long-standing myxedema, especially if cardiovascular impairment suspected where extreme caution recommended

Maintenance: 1 tab Thyrolar 1 to 1 tab Thyrolar 2 per day; failure to respond to tab Thyrolar 3 may suggest lack of compliance or malabsorption

Adjust dose within the first 4 weeks of therapy after proper clinical laboratory evaluations where serum levels of T4 bound and free TSH are measured

Administer before breakfast

Dosage Forms & Strengths

Each 60 mg tablet will replace approximately 60-65 mg (1 grain) of desicated thyroid

Liothyronine sodium (T3) is approximately 4 times as potent as levothyroxine (T4)

tablet, T3/T4

  • Thyrolar 1/4 (15mg): 3.1/12.5mcg
  • Thyrolar 1/2 (30mg): 6.25/25mcg
  • Thyrolar 1 (60mg): 12.5/50mcg
  • Thyrolar 2 (120mg): 25/100mcg
  • Thyrolar 3 (180mg): 37.5/150mcg
more...

Congenital Hypothyroidism

0-6 months: 3.1/12.5 to 6.25/25 PO;

6-12 months: 6.25/25 to 9.35/37.5 PO;

1-5 years: 9.35/37.5-12.5/50 mcg PO;

6-12 years: 12.5/50-18.75/75 mcg PO;

>12 years: >18.75/75 mcg PO;

Administration: Before breakfast

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Interactions

Interaction Checker

liotrix and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            Frequency Not Defined

            Arrhythmias

            Increased blood pressure

            Chest pain

            Palpitation

            Anxiety

            Headache

            Urticaria

            Changes in menstrual cycle

            Insomnia

            Hyperhydrosis pruritus

            Tachycardia

            Nervousness

            Tremor

            Cramps

            Increased appetite

            Weight loss

            Diarrhea

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            Warnings

            Black Box Warnings

            Thyroid hormones, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss

            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 their anorectic effects.

            Contraindications

            Hypersensitivity to thyroid hormone

            Acute MI uncomplicated by hypothyroidism, untreated thyrotoxicosis, untreated adrenal insufficiency

            Treatment of obesity

            Cautions

            Caution in angina, cardiovascular disease, HTN, endocrine disorders, elderly

            Use caution in patients with adrenal insufficiency (symptoms may become exagerated or aggravated)

            Euthroid withdrawn from U.S. market

            Use caution in patients with myxedema (symptoms may become exagerated or aggravated)

            No advantage over levothyroxine & may do more harm (T3 overdosage) than good

            Not for the treatment of female infertility in euthyroid patients

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            Pregnancy & Lactation

            Pregnancy Category: A

            Lactation: Small amount excreted into breast milk, use caution

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

            more...
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            Pharmacology

            Mechanism of Action

            Natural thyroid hormone; increases basal metabolic rate, increases utilization and mobilization of glycogen store, promotes gluconeogenesis

            Pharmacokinetics

            Half-Life (T4): 6-7 days (euthyroid); 3-4 days (hyperthyroid); 9-10 days (hypothyroid)

            Half-life (T3): 2.5 days

            Onset: 48 hr

            Absorption: 40-80% (T4); 95% (T3)

            Max effect: 8-10 days

            Peak Plasma Time: 12-48 hr

            Bioavailability: 50-95%

            Protein Bound: 99% (T4)

            Metabolism: Liver, also in kidney & intestinal walls

            Metabolites: Triiodothyronine (T3)

            Excretion: Urine (major), feces

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            Formulary

            FormularyPatient Discounts

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            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
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            ST Step Therapy
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