How to Calculate Isotretinoin Dose

This calculator determines either the therapy duration or daily dose of isotretinoin based on patient weight, cumulative dose, and calculation type, using these guidelines:

Cumulative Dose (mg):

Duration (days):

Daily Dose (mg):

Where:

• Weight: Patient’s weight in kg or lb (converted to kg internally, default 100 kg).
• Cumulative Dose Known: No (use 135 mg/kg mean) or Yes (user-specified in mg).
• Calculation Type: Therapy duration or daily dose.
• Daily Dose: User-specified dose in mg (for duration calculation, max 100 mg/day).
• Duration: User-specified duration in weeks (required) and days (optional, 0–6, default empty) for daily dose calculation.

Dosing limits: Start ≤ 50 mg/day, maximum 100 mg/day.

Using the Isotretinoin Dose Calculator

This tool estimates either the therapy duration or daily dose of isotretinoin for acne treatment. Enter the patient’s weight (in kg or lb, default 100 kg), select if the cumulative dose is known (use mean 135 mg/kg or specify exact dose), choose to calculate duration or daily dose, provide the daily dose (for duration) or duration in weeks and days (for daily dose, days optional). Results show the calculated value, cumulative dose, recommended range, and dosing limits.

Example: Weight 220 lb, No cumulative dose known, Calculate duration, Daily Dose 5 mg:

Isotretinoin Therapy Duration Calculation:
Patient's Weight: 220.0 lb (99.8 kg)
Daily Dose: 5.0 mg
Cumulative Dose: 13,473 mg
Duration: 384 weeks5 days
dose should range from 11,976 to 14,970 mg.

            

Consult a healthcare provider before administering.

Frequently Asked Questions (FAQ)

1. What is isotretinoin used for?

Isotretinoin treats severe acne (nodular or cystic) that hasn’t responded to other treatments.

2. How is the dose determined?

It’s based on weight, with a cumulative dose of 120–150 mg/kg (mean 135 mg/kg), daily doses ≤ 100 mg, starting ≤ 50 mg/day.

3. What are the risks of isotretinoin?

Risks include teratogenicity (birth defects), liver issues, and retinopathy; regular monitoring is required.

4. Can isotretinoin be used long-term?

No, it’s typically taken for 15–20 weeks, but duration depends on cumulative dose and response, with close medical supervision.

5. How should I monitor my treatment?

Regular blood tests (liver function, lipids), pregnancy tests (for females), and eye exams are recommended due to risks like retinopathy.