Mercaptamine
Mercaptamine Uses, Dosage, Side Effects, Food Interaction and all others data.
Cystinosis is a rare disease caused by mutations in the CTNS gene that encodes for cystinosin, a protein responsible for transporting cystine out of the cell lysosome. A defect in cystinosin function is followed by cystine accumulation throughout the body, especially the eyes and kidneys.
Several preparations of cysteamine exist for the treatment of cystinosis manifestations, some in capsule form, and others in ophthalmic solution form. In particular, cystine deposits on the eye can cause significant discomfort throughout the day and require frequent treatment with eye drops, typically every waking hour.
On August 25th 2020, the first ophthalmic solution for cystinosis requiring only 4 daily treatments was granted FDA approval. Mercaptamine eye drops are a practical and effective option for those affected by ocular cystinosis. Marketed by Recordati Rare Diseases Inc., CYSTADROPS® reduce the burden of multiple frequent medications normally administered to those with cystinosis.
| Trade Name | Mercaptamine |
| Availability | Prescription only |
| Generic | Cysteamine |
| Cysteamine Other Names | Cysteamine, Mercaptamina, Mercaptamine, Mercaptaminum, Thioethanolamine |
| Related Drugs | Cystagon, Procysbi |
| Type | |
| Formula | C2H7NS |
| Weight | Average: 77.149 Monoisotopic: 77.029919919 |
| Protein binding | Cysteamine is 52% plasma protein bound, and is mostly bound to albumin. |
| Groups | Approved, Investigational |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Mercaptamine is a cystine depleting agent used to treat the effects of cystinosis.
The bitartrate salt of cysteamine is used for the oral treatment of nephropathic cystinosis and cystinuria in children 6 years old and above, and adults. The hydrochloride salt, used in eye drop preparations, is indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis.
Mercaptamine is also used to associated treatment for these conditions: Cystinosis, Nephropathic, Corneal cystine crystal accumulation
How Mercaptamine works
Individuals born without the ability to metabolize cystine suffer from cystinosis, a rare genetic disorder characterized by the widespread accumulation of cystine crystals throughout the body and eye tissues. The cystine crystals may cause considerable damage, particularly in the renal tissues and corneal tissues. In some cases, renal failure can occur during childhood if the condition is left untreated. Other organs that may be affected by cystinosis include the CNS, thyroid, pancreas, muscle tissues, and gonads.
Mercaptamine converts cystine to cysteine and cysteine-cysteamine mixed disulfides, reducing the buildup of corneal cystine crystals. This drug participates in a thiol-disulfide interchange reaction with lysosomes, leading to cysteine exit from the lysosome in patients diagnosed with cystinosis.
Toxicity
Two cases of human overdoses with cysteamine are recorded in the literature, according to prescribing information. In one case, vomiting was immediate after the administration of cysteamine, and the patient did not experience other symptoms. A 200 to 250 mg/kg dose was accidentally ingested by a healthy 13-month-old child. Vomiting and dehydration followed. A full recovery was made after hospitalization and the replenishment of fluids.
There is no known antidote for an overdose with cysteamine. In the case of an overdose, provide supportive treatment, especially to the cardiovascular and respiratory systems. Hemodialysis may be useful in some cases due to the fact that cysteamine has poor plasma protein binding.
Food Interaction
- Take on an empty stomach. The delayed-release capsules should be taken at least 30 minutes before or 2 hours after a high-fat meal to ensure adequate exposure.
- Take with or without food. The immediate release preparation can be taken with or without food.
Mercaptamine Disease Interaction
Volume of Distribution
Mercaptamine has a volume of distribution of about 129 L, according to one pharmacokinetic study. Prescribing information indicates a volume of distribution of 382 L for the delayed-release formulation and 198 L for the immediate-release preparation. It is known to cross the blood-brain barrier.
Elimination Route
Orally administered cysteamine is absorbed in the gastrointestinal tract and reaches its maximum plasma concentration in about 1.4 hours, with some variation according to the type of formulation (delayed versus immediate-release). One pharmacokinetic study of adults with Cystic Fibrosis revealed a Cmax of 2.86 mg/L.The maximum plasma concentration after administration of cysteamine eye drops is unknown, however, it is likely to be considerably lower than oral administration.
According to prescribing information, the AUC 0-12 h for the delayed-release oral tablets is 99.26 ± 44.2 μmol*h/L with a Cmax of 27.70 ± 14.99 μmol/L.
The AUC 0-12 for the immediate-release tablets is 192.00 ± 75.62 μmol*h/L with a Cmax of 37.72 ± 12.10 μmol/L.
Half Life
The half-life of cysteamine is about 3.7 hours.
Clearance
The plasma clearance of cysteamine is about 1.2 - 1.4 L/min. One reference mentions a clearance of 89.9 L/h in patients with Cystic Fibrosis.
Innovators Monograph
You find simplified version here Mercaptamine
