LEVOTHYROXINE SODIUM

Indications & Dose:

Hypothyroidism

• BY MOUTH

Adult 18–49 years: Initially 50–100 micrograms once daily; adjusted in steps of 25–50 micrograms every 3–4 weeks, adjusted according to response; maintenance 100–200 micrograms once daily, dose to be taken preferably at least 30 minutes before breakfast, caffeine-containing liquids (e.g. coffee, tea), or other medication

Adult 50 years and over: Initially 25 micrograms once daily; adjusted in steps of 25 micrograms every 4 weeks, adjusted according to response; maintenance 50–200 micrograms once daily, dose to be taken preferably at least 30 minutes before breakfast, caffeine-containing liquids (e.g. coffee, tea), or other medication

Hypothyroidism in patients with cardiac disease | Severe hypothyroidism

• BY MOUTH

Adult: Initially 25 micrograms once daily; adjusted in steps of 25 micrograms every 4 weeks, adjusted according to response; maintenance 50–200 micrograms once daily, dose to be taken preferably at least 30 minutes before breakfast, caffeine-containing liquids (e.g. coffee, tea), or other medication

Hyperthyroidism (blocking-replacement regimen) in combination with carbimazole

• BY MOUTH

Adult: 50–150 micrograms daily therapy usually given for 18 months 

Contraindications:

Acute MI (unless caused or complicated by hyperthyroidism), hypersensitivity to levothyroxine or its components, uncorrected adrenal insufficiency, untreated thyrotoxicosis 

Side Effects:

Cautions:

Precautions:

Interaction:

DRUGS

adrenocorticoids: Possibly adrenocorticoid dosage adjustments as thyroid status changes

aluminum- and magnesium-containing antacids, bile acid sequestrants, calcium carbonate, cation exchange resins, cholestyramine, colestipol, ferrous sulfate, kayexalate, orlistat, sucralfate: Possibly reduced effects of levothyroxine amiodarone,
iodide:

Possibly hyperthyroidism beta blockers: Possibly impaired action of beta blockers and decreased conversion of T4 to triiodothyronine (T3) cholestyramine,

colestipol: Delayed or inhibited levothyroxine

absorption digoxin: Reduced digoxin effects estrogen,

phenylbutazone, phenytoin: Reduced binding of levothyroxine to protein, possibly requiring increased levothyroxine dosage

insulin, oral antidiabetic drugs: Possibly uncontrolled diabetes mellitus, requiring increased dosage of insulin or oral antidiabetic drug

ketamine: Possibly hypertension and tachycardia

maprotiline: Increased risk of arrhythmias

oral anticoagulants: Altered anticoagulant activity, possibly need for anticoagulant dosage adjustment

selective serotonin reuptake inhibitors, tricy-clic and tetracyclic antidepressants: Increased therapeutic and toxic effects of both drugs

sympathomimetics: Increased risk of coronary insufficiency in patients with coronary artery disease

theophyttine: Decreased theophylline clearance 

Warnings:

Adverse Effects:

Lactations:

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

CNS: Fatigue, headache, insomnia, somnolence
ENDO: Hyperthyroidism (with overdose)
GI: Dysphagia
MS: Muscle weakness, myalgia, slipped capital femoral epiphysis
SKIN: Alopecia (transient), rash, urticaria
Other: Weight gain 

Patient And Carer Advice: