Propyl-Thyracil
Propyl-Thyracil (propylthiouracil) is an antithyroid medication that inhibits the synthesis of thyroid hormones by blocking the action of thyroid peroxidase. It also inhibits the peripheral conversion of T4 to T3. Due to the risk of severe liver injury and acute liver failure, it is typically reserved for patients who cannot tolerate methimazole, or for pregnant women during their first trimester.
Dosage by Body Weight
Adult dosing usually starts at 300 mg per day, divided into three equal doses administered every 8 hours. Severe hyperthyroidism may require higher initial doses. Maintenance doses typically range from 100 to 150 mg per day once thyroid levels normalize. Pediatric dosing is highly restricted due to hepatotoxicity risks and must be managed exclusively by a pediatric endocrinologist.
- Body Weight
- Below 5 kg
- Dose
- Not routine
- Frequency
- Use only if prescribed
- Tracking Notes
- Not recommended in infants. Pediatric endocrinology consultation is mandatory due to risk of severe liver injury.
- Body Weight
- 5-7 kg
- Dose
- 8.3 mg to 16.3 mg per dose
- Frequency
- Three times daily (every 8 hours)
- Tracking Notes
- Calculated based on 5-7 mg/kg/day divided into 3 doses. Requires close clinical and laboratory monitoring.
- Body Weight
- 8-10 kg
- Dose
- 13.3 mg to 23.3 mg per dose
- Frequency
- Three times daily (every 8 hours)
- Tracking Notes
- Calculated based on 5-7 mg/kg/day divided into 3 doses. Monitor liver function enzymes regularly.
- Body Weight
- 11-15 kg
- Dose
- 18.3 mg to 35 mg per dose
- Frequency
- Three times daily (every 8 hours)
- Tracking Notes
- Calculated based on 5-7 mg/kg/day divided into 3 doses. Advise parents to monitor for signs of liver dysfunction.
- Body Weight
- 16-20 kg
- Dose
- 26.7 mg to 46.7 mg per dose
- Frequency
- Three times daily (every 8 hours)
- Tracking Notes
- Calculated based on 5-7 mg/kg/day divided into 3 doses. Promptly report any sore throat, fever, or unusual bruising.
| Body Weight | Dose | Frequency | Tracking Notes |
|---|---|---|---|
| Below 5 kg | Not routine | Use only if prescribed | Not recommended in infants. Pediatric endocrinology consultation is mandatory due to risk of severe liver injury. |
| 5-7 kg | 8.3 mg to 16.3 mg per dose | Three times daily (every 8 hours) | Calculated based on 5-7 mg/kg/day divided into 3 doses. Requires close clinical and laboratory monitoring. |
| 8-10 kg | 13.3 mg to 23.3 mg per dose | Three times daily (every 8 hours) | Calculated based on 5-7 mg/kg/day divided into 3 doses. Monitor liver function enzymes regularly. |
| 11-15 kg | 18.3 mg to 35 mg per dose | Three times daily (every 8 hours) | Calculated based on 5-7 mg/kg/day divided into 3 doses. Advise parents to monitor for signs of liver dysfunction. |
| 16-20 kg | 26.7 mg to 46.7 mg per dose | Three times daily (every 8 hours) | Calculated based on 5-7 mg/kg/day divided into 3 doses. Promptly report any sore throat, fever, or unusual bruising. |
Formulation
Purpose
Treatment of hyperthyroidism, Graves' disease, toxic multinodular goiter, or to manage thyroid symptoms in preparation for thyroidectomy or radioactive iodine therapy.
Generic Name
PropylthiouracilScheduled Drug
Yes. This medicine should be supplied or used only according to applicable prescription and regulatory requirements.