mercaptamine bitartrate at a glance
Medicine class
Cystine-depleting metabolic treatment
Licensed use
Proven nephropathic cystinosis in adults and children
Available forms
Conventional hard capsules and gastro-resistant hard capsules
Eye treatment
Oral treatment does not prevent corneal cystine crystals; prescribed eye drops may still be needed
What is mercaptamine bitartrate used for?
The selected products are licensed for:
Treatment of proven nephropathic cystinosis, reducing cystine accumulation in cells and delaying renal failure when started early.
How does mercaptamine bitartrate work?
Cysteamine reacts with cystine inside lysosomes to form compounds that can leave through another transport pathway. This reduces cystine retained within cells, including white blood cells, muscle and liver cells.
mercaptamine bitartrate preparations and strengths
Capsule
Route: Oral
Strengths: 25 mg, 50 mg, 75 mg, 150 mg
How to take mercaptamine bitartrate
Follow the instructions for the specific formulation because conventional and gastro-resistant capsules have different food and handling requirements.
Swallow capsules as directed; do not crush or chew gastro-resistant capsules or their granules.
Cystagon may be taken with or just after food to improve digestive tolerance. For a child at risk of choking, its capsule may be opened and mixed with a suitable starch-based food; acidic drinks are generally unsuitable for mixing.
Procysbi may be swallowed whole or opened so intact granules can be mixed with apple sauce or fruit jam, or administered through a suitable gastric feeding tube. Keep its relationship to food consistent and follow supplied food restrictions.
Do not independently substitute one formulation for another.
mercaptamine bitartrate side effects
Common or expected effects
- Nausea, vomiting, diarrhoea or reduced appetite
- Abdominal pain or indigestion
- Tiredness, lethargy or fever
- Headache
- Noticeable breath or skin odour
- Rash
- Abnormal liver-function test results
Get urgent medical advice
- Severe allergic reaction
- Gastrointestinal ulceration or bleeding
- Severe blistering or peeling skin reaction
- Seizures, encephalopathy or pronounced drowsiness
- Severe headache or visual symptoms associated with raised pressure around the brain
- Skin fragility, stretch marks, elbow lesions or bone abnormalities
- Nephrotic syndrome or reduced white-cell count
mercaptamine bitartrate in pregnancy
Human pregnancy information is inadequate, while animal studies found reproductive toxicity and malformations. Treatment is generally avoided during pregnancy, especially early pregnancy, unless a specialist concludes it is clearly necessary. Anyone planning pregnancy or becoming pregnant should contact their specialist promptly so the risks of treatment and untreated cystinosis can be reconsidered.
mercaptamine bitartrate while breastfeeding
Breastfeeding is contraindicated with the selected products. It is unknown whether cysteamine enters human milk, and animal findings raise concern about harm to nursing offspring; discuss feeding and treatment options with the specialist team.
mercaptamine bitartrate interactions
Give the specialist and pharmacist a complete list of prescribed, non-prescribed and complementary products. Interaction evidence is limited and differs by formulation.
Bicarbonate replacement
Do not take bicarbonate at the same time as Procysbi because it may cause the gastro-resistant granules to release cysteamine too early; follow specialist timing instructions.
Medicines dependent on CYP enzymes or P-gp, BCRP, OATP or OCT transporters
Procysbi may theoretically alter exposure to some substrates of these pathways, although the clinical relevance is uncertain; review important concomitant medicines.
Common questions about mercaptamine bitartrate
Answers are fully visible for fast scanning and source review.
What is mercaptamine bitartrate used for?
It is used to treat proven nephropathic cystinosis by reducing cystine accumulation within cells.
Are mercaptamine and cysteamine the same active treatment?
Yes. Mercaptamine is another name for cysteamine; the selected capsules contain it as mercaptamine bitartrate.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.