Adult dose and duration800 mg a day in three divided doses, on top of fluids and alkali. US label verbatim: "Adults: The recommended initial dosage in adult patients is 800 mg/day. In clinical studies, the average dosage was about 1,000 mg/day." and "Administer THIOLA EC in 3 divided doses at the same times each day, with or without food. Maintain a routine pattern with regard to meals." The dose is then set by a urine test, verbatim: "Measure urinary cystine 1 month after starting THIOLA EC and every 3 months thereafter. Adjust THIOLA EC dosage to maintain urinary cystine concentration less than 250 mg/L." A patient who has had severe toxicity to penicillamine starts lower. - Indefinite, because cystinuria is a lifelong inherited transport defect. There is no course to finish - the review points are the three-monthly urinary cystine and the three- to six-monthly urine protein.
Paediatric dose15 mg/kg/day
(Licensed from 20 kg, and cystinuria is one of the few stone diseases that starts in childhood. US label verbatim: "Pediatrics: The recommended initial dosage in pediatric patients weighing 20 kg and greater is 15 mg/kg/day. Avoid dosages greater than 50 mg/kg per day in pediatric patients", given in three divided doses. The reason for that ceiling is in the cautions: "Pediatric patients receiving greater than 50 mg/kg of tiopronin per day may be at increased risk for proteinuria." A child with a stone belongs with paediatric nephrology, not on a prescription written in a primary-care clinic.)
Not for children under 20 kg
Dose by weight| 20kg | 300 mg/day |
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| 21kg | 315 mg/day |
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| 22kg | 330 mg/day |
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| 23kg | 345 mg/day |
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| 24kg | 360 mg/day |
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| 25kg | 375 mg/day |
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| 26kg | 390 mg/day |
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| 27kg | 405 mg/day |
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| 28kg | 420 mg/day |
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| 29kg | 435 mg/day |
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| 30kg | 450 mg/day |
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| 31kg | 465 mg/day |
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| 32kg | 480 mg/day |
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| 33kg | 495 mg/day |
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| 34kg | 510 mg/day |
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| 35kg | 525 mg/day |
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| 36kg | 540 mg/day |
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| 37kg | 555 mg/day |
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| 38kg | 570 mg/day |
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| 39kg | 585 mg/day |
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| 40kg | 600 mg/day |
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| 41kg | 615 mg/day |
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| 42kg | 630 mg/day |
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| 43kg | 645 mg/day |
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| 44kg | 660 mg/day |
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| 45kg | 675 mg/day |
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| 46kg | 690 mg/day |
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| 47kg | 705 mg/day |
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| 48kg | 720 mg/day |
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| 49kg | 735 mg/day |
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| 50kg | 750 mg/day |
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Dose sourceTHIOLA EC (tiopronin) delayed-release tablets US prescribing information, section 1 Indications and Usage, section 2.1 Recommended Dosage, section 2.3 Monitoring and section 5 Warnings and Precautions (DailyMed SetID 20298a52-a194-a161-8632-d84b6f26e23c)
WhyThe disease article names the drug in its section on preventing the next stone by stone type: a cystine-stone former needs a large urine output, 3000 mL a day or more, and a urine pH kept at 7.5 or above so cystine stays dissolved; potassium citrate is the preferred alkaliniser, and tiopronin or another thiol drug lowers urinary cystine. The US label's licensed use covers the same disease and the same three supporting measures: it is indicated, combined with high fluid intake, alkali and diet change, for preventing cystine stones in adults and children 20 kg and over with severe homozygous cystinuria not controlled by those measures alone. Cystine stones make up roughly 1% of stones but recur relentlessly, present in childhood or adolescence, and resist lithotripsy. The row is marked adjunct and third line because it does nothing for the colic in front of you - the analgesics and tamsulosin on the card handle that. Egypt has no registered tiopronin product, so no local brand or price can be shown.
Cautions- It prevents the next stone; it does nothing for this one. The presentation here is acute renal colic. Tiopronin is a three-times-a-day lifelong drug started after the stone type is known - a cystine stone on analysis, or cystinuria on a 24-hour urine - and it does not belong in an emergency prescription.
- RED FLAG - proteinuria and nephrotic syndrome. US label verbatim: "Proteinuria, including nephrotic syndrome, and membranous nephropathy, have been reported with tiopronin use." and "Monitor patients for the development of proteinuria and discontinue therapy in patients who develop proteinuria." The label's schedule is verbatim: "Assess for proteinuria before treatment and every 3 to 6 months during treatment." A drug for kidney stones that can damage the kidney is not one to start and forget.
- The dose is titrated against a laboratory number, not against symptoms. US label verbatim: "Adjust THIOLA EC dosage to maintain urinary cystine concentration less than 250 mg/L." Without access to urinary cystine measurement the dose cannot be managed properly, and that is a reason to refer rather than to guess.
- Hypersensitivity reactions. US label verbatim: "Hypersensitivity reactions (drug fever, rash, fever, arthralgia and lymphadenopathy) have been reported", and known hypersensitivity to tiopronin is a contraindication.
- The fluid and the alkali are not optional extras. The label indicates the drug only where it is combined with a high fluid intake, an alkali, and a change of diet - and the article sets the targets: urine output over 3000 mL a day and a urine pH of 7.5 or higher, with potassium citrate as the alkaliniser. A patient who will not drink will not be rescued by the tablet.
- No Egyptian product exists, so tiopronin cannot be filled at a Cairo pharmacy.
Egyptian brandsNo Egyptian brand matched — prescribe by generic name.