Thyrox 25mcg Tablet

✔️ Side Effects

Usually linked to overdosage, mimicking hyperthyroidism:

• General: Weight loss, fatigue, heat intolerance, sweating
• CNS: Headache, insomnia, nervousness, anxiety
• Muscle: Tremors, weakness
• Cardiac: Palpitations, tachycardia, arrhythmias, increased BP
• GI: Diarrhea, vomiting, abdominal pain
• Skin: Hair thinning, flushing
• Respiratory: Shortness of breath

✔️ Dosage & Administration

Adults:

• Initial dose: 25–50 mcg/day, gradually increasing every 6–8 weeks in 12.5–25 mcg steps until TSH normalizes.
• Severe hypothyroidism: Start with 12.5–25 mcg/day and increase every 2–4 weeks with TSH monitoring.
• Secondary or tertiary hypothyroidism: Adjust dose to normalize free T4.
• Older adults or cardiac patients: 1.7 mcg/kg/day.

Pediatric:

• Newborns: 10–15 mcg/kg/day; use a lower dose if there's a cardiac risk.
• Infants/Children: Start with 25 mcg/day for severe cases, increase every 2–4 weeks as needed.

By age group:

0–3 months: 10–15 mcg/kg/day

3–6 months: 8–10 mcg/kg/day

6–12 months: 6–8 mcg/kg/day

1–5 years: 5–6 mcg/kg/day

6–12 years: 4–5 mcg/kg/day

12 years (growth/pubertal incomplete): 2–3 mcg/kg/day

After puberty: 1.7 mcg/kg/day

Dose adjustments should be based on clinical status and lab results.

✔️ Drug Interactions

• May enhance effects and toxicity of tricyclic antidepressants, increasing risk of arrhythmias and CNS stimulation.
• Sertraline may increase levothyroxine requirements.
• Can alter insulin or antidiabetic medication needs—monitor glucose levels closely.
• Digitalis effectiveness may be reduced as thyroid function improves.

✔️ Contraindications

• Untreated thyrotoxicosis
• Acute myocardial infarction
• Uncorrected adrenal insufficiency

✔️ Use in Pregnancy & Lactation

• Pregnancy Category A: Safe when clinically indicated; dosage may need adjustment.
• Minimal transfer to breast milk, but adequate dosing is essential for lactation and infant development.

✔️ Precautions

• Adrenal insufficiency should be addressed before starting therapy to avoid adrenal crisis.
• Use caution in cardiac patients and the elderly; avoid rapid dose escalation.
• Monitor for dosage adjustments if body weight changes significantly.
• TSH and free T4 should be monitored to maintain target levels and prevent overdose.

✔️ Storage:

Store below 30°C, in a dry, light-protected area.

Keep out of reach of children.