RELISTOR SOLUTION FOR INJECTION 12MG/0.6ML

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.

Active Ingredient / Synonyms

MNTX | Methylnaltrexone |

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.

Pharmacodynamics

Use of opioids induces slowing of gastrointestinal motility and transit. Following remifentanil administration, the methylnaltrexone and placebo groups showed no change in pupiliary constriction while the naloxone group showed a marked change over the time interval tested.

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:

Most of the drug is eliminated as unchanged drug (85% of administered radioactivity). Approximately half of the dose is excreted in the urine and somewhat less in feces.

Half-life

terminal: 8.89 ± 2.59 h (intravenous) terminal: 6.14- 8.83 h (subcutaneous)

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.

References

  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank

Although best effort has been made to ensure the information provided is correct and updated, users are advised to visit HSA Official website whenever in doubt. Please see Disclaimers.
We welcome all the content error reporting/feedback. Please contact us @ Text Us!

Approval Information

RELISTOR SOLUTION FOR INJECTION 12MG/0.6ML was registered with Health Science Authority of Singapore by LINK HEALTHCARE SINGAPORE PTE LTD. It is marketed with the registration number of SIN13783P with effective from 2010-07-04.

This product contains 12mg/0.6mL of Methylnaltrexone in the form of INJECTION, SOLUTION.

The medicine was manufactured by DSM Pharmaceuticals in UNITED STATES

It is a Presciption Only Medicine which can only be obtained from a doctor or a dentist, or from a pharmacist with a prescription from a Singapore-registered doctor or dentist.

Anatomical Therapeutic Chemical (ATC) Classification

ATC Code: A06AH01

Products Containing as Single Ingredient

Drug ID Trade Name Active Ingredients Forensic Class Registrant Status
1 DEXTROMETHORPHAN LINCTUS 15mg/5ml Dextromethorphan P Only DRUG HOUSES OF AUSTRALIA PTE LTD Active
22 ZENMOLIN SYRUP 2mg/5ml Salbutamol P Only DRUG HOUSES OF AUSTRALIA PTE LTD Active
41 APO-PROPRANOLOL TABLET 40mg Propranolol POM PHARMAFORTE SINGAPORE PTE LTD Active
42 APO-DIAZEPAM TABLET 2mg Diazepam POM PHARMAFORTE SINGAPORE PTE LTD Active
44 APO-DIAZEPAM TABLET 5mg Diazepam POM PHARMAFORTE SINGAPORE PTE LTD Active
45 APO-DIAZEPAM TABLET 10mg Diazepam POM PHARMAFORTE SINGAPORE PTE LTD Active
46 APO-PROPRANOLOL TABLET 10mg Propranolol POM PHARMAFORTE SINGAPORE PTE LTD Active
55 APO-ISDN TABLET 10mg Isosorbide Dinitrate POM PHARMAFORTE SINGAPORE PTE LTD Active
63 DIAPO TABLET 10mg Diazepam POM BEACONS PHARMACEUTICALS PTE LTD Active
64 FURMIDE TABLET 40mg Furosemide POM BEACONS PHARMACEUTICALS PTE LTD Active

Products Containing as Mixture Ingredient

Drug ID Trade Name Active Ingredients Forensic Class Registrant Status
5 DIPHENHYDRAMINE EXPECTORANT PAED. Ammonium Chloride|Diphenhydramine|Sodium Citrate P Only DRUG HOUSES OF AUSTRALIA PTE LTD Active
400 FAKTU SUPPOSITORY Cinchocaine|Policresulen P Only TAKEDA PHARMACEUTICALS (ASIA PACIFIC) PTE LTD Active
407 TRIMAXAZOLE TABLET Sulfamethoxazole|Trimethoprim POM BEACONS PHARMACEUTICALS PTE LTD Active
435 APO-SULFATRIM TABLET Sulfamethoxazole|Trimethoprim POM PHARMAFORTE SINGAPORE PTE LTD Active
508 APO-SULFATRIM PEDIATRIC TABLET Sulfamethoxazole|Trimethoprim POM PHARMAFORTE SINGAPORE PTE LTD Active
526 B.S. SUSPENSION Sulfamethoxazole|Trimethoprim POM APEX PHARMA MARKETING PTE LTD Active
583 CO-TRIMEXAZOLE SUSPENSION Sulfamethoxazole|Trimethoprim POM BEACONS PHARMACEUTICALS PTE LTD Active
676 BANEOCIN OINTMENT Bacitracin|Neomycin POM NOVARTIS (SINGAPORE) PTE LTD Active
678 BANEOCIN POWDER Bacitracin|Neomycin POM NOVARTIS (SINGAPORE) PTE LTD Active
706 TIENAM 500 FOR INJECTION Imipenem|Cilastatin POM MSD PHARMA (SINGAPORE) PTE LTD Active