Product Information
Registration Status: ActiveRELISTOR SOLUTION FOR INJECTION 12MG/0.6ML is approved to be sold in Singapore with effective from 2010-07-04. It is marketed by LINK HEALTHCARE SINGAPORE PTE LTD, with the registration number of SIN13783P.
This product contains Methylnaltrexone 12mg/0.6mL in the form of INJECTION, SOLUTION. It is approved for SUBCUTANEOUS use.
This product is manufactured by DSM Pharmaceuticals in UNITED STATES.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Description
Methylnaltrexone is a pheriphally-acting μ-opioid antagonists that acts on the gastrointestinal tract to decrease opioid-induced constipation without producing analgesic effects or withdrawal symptoms. It is also a weak CYP2D6 inhibitor. FDA approved in 2008.
Indication
Treatment of opioids induced constipation in palliative patients that are inadequately responding to laxative therapy.
Mechanism of Action
Methylnaltrexone is a pheriphally-acting μ-opioid antagonists that acts on the gastrointestinal tract inhibit opioid-induced decrease in gastric motility and transit time. Because methylnaltrexone is a quaternary derivative of naltrexone, it produces its gastrointestinal effects without producing analgesic effects or withdrawal symptoms as it does not cross the blood-brain-barrier.
Pharmacokinetics
- Absorption
- Methylnaltrexone is rapidly absorbed. Tmax (SubQ): 30 minutes (regardless of dose); Cmax, 0.15 mg/kg SubQ dose = 117 ng/mL; AUC24, 0.15 mg/kg SubQ dose = 175 ng·hr/mL;
- Distribution
- Volume of distribution, steady state = 1.1 L/kg
- Metabolism
- 60% of the dose is metabolized. Conversion to methyl-6-naltrexol isomers (5% of total dose) and methylnaltrexone sulfate (1.3% of total dose) appear to be the primary pathways of metabolism. N‑demethylation of methylnaltrexone to produce naltrexone is not significant.
- Elimination
Clearance
10.5 ± 1.5 ml/min/kg (IV)
Toxicity
LD50: 50 mg/kg (primates); Orthostatic hypotension at plasma levels in excess of 1.400 ng/mL. The most common (>5%) adverse reactions reported with methylnaltrexone bromide are abdominal pain, flatulence, nausea, dizziness, diarrhea and hyperhidrosis.
Active Ingredient/Synonyms
MNTX | Methylnaltrexone |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.