Formulary
Mercaptamine: Indications, Dosing, Side Effects and Interactions
Mercaptamine clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 3 min read
Mercaptamine: Indications, Dosing, Side Effects and Interactions
Mercaptamine clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Corneal cystine crystal deposits in patients with cystinosis (specialist use only)**
- **Adult** (To The Eye): Apply 1 drop 4 times a day, to be applied to both eyes (minimum 4 hours between doses); dose may be reduced according to response (minimum daily dose 1 drop in each eye).
**Nephropathic cystinosis (specialist use only)**
- **Adult** (By Mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein (measured using the mixed leucocyte assay), maintenance 650 mg/m 2 twice daily, administered every 12 hours; maximum 1.95 g/m 2 per day.
**Corneal cystine crystal deposits in patients with cystinosis (specialist use only) for mercaptamine**
- **Child 2-17 years** (To the eye): Apply 1 drop 4 times a day, to be applied to both eyes (minimum 4 hours between doses); dose may be reduced according to response (minimum daily dose 1 drop in each eye).
**Nephropathic cystinosis (specialist use only) for Cystagon**
- **Neonate** (By mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased gradually over 4-6 weeks to avoid intolerance, dose increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein, maintenance 325 mg/m2 4 times a day; maximum 1.95 g/m2 per day.
- **Child 1 month-11 years (body-weight up to 50 kg)** (By mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased gradually over 4-6 weeks to avoid intolerance, dose increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein, maintenance 325 mg/m2 4 times a day; maximum 1.95 g/m2 per day.
- **Child 12-17 years (body-weight up to 50 kg)** (By mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased gradually over 4-6 weeks to avoid intolerance, dose increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein, maintenance 325 mg/m2 4 times a day; maximum 1.95 g/m2 per day.
- **Child 12-17 years (body-weight 50 kg and above)** (By mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased gradually over 4-6 weeks to avoid intolerance, dose increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein, maintenance 500 mg 4 times a day; maximum 1.95 g/m2 per day.
**Nephropathic cystinosis (specialist use only) for Procysbi**
- **Neonate** (By mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein (measured using the mixed leucocyte assay), maintenance 650 mg/m2 twice daily, administered every 12 hours; for approximations of maintenance dose-consult product literature; maximum 1.95 g/m2 per day.
- **Child** (By mouth): Initially one-sixth to one-quarter of the expected maintenance dose, increased if there is adequate tolerance and the leucocyte-cystine concentration remains above 1 nanomol hemicystine/mg protein (measured using the mixed leucocyte assay), maintenance 650 mg/m2 twice daily, administered every 12 hours; for approximations of maintenance dose-consult product literature; maximum 1.95 g/m2 per day.
Cautions
When used by eye Contact lens wearers With oral use Dose of phosphate supplement may need to be adjusted if transferring from phosphocysteamine to mercaptamine
Side effects
Common or very common When used by eye (topical) Dry eye; eye discomfort; eye disorders; vision blurred With oral use Appetite decreased; asthenia; breath odour; diarrhoea; drowsiness; encephalopathy; fever; gastroenteritis; gastrointestinal discomfort; headache; nausea; skin reactions; vomiting Uncommon With oral use Compression fracture; gastrointestinal ulcer; hair colour changes; hallucination; joint hyperextension; leg pain; leucopenia; musculoskeletal disorders; nephrotic syndrome; nervousness; osteopenia; seizure Frequency not known With oral use Depression; intracranial pressure increased; papilloedema
Pregnancy
With oral use: Manufacturer advises avoid-teratogenic and toxic in animal studies.
Breast feeding
With oral use: Manufacturer advises avoid-no information available.
Medicinal forms
Drops,Capsule,Capsule,Drops
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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