Treatment of opioid-induced constipation in people with advanced diseases receiving palliative care, in which the response to laxatives was not sufficient.
Composition:
One vial (0.6 ml) contains 12 mg methylnaltrexone bromide.
Action:
Selective antagonist of the opioid receptor mi receptor. The ability of methyl Naltrexone, as a quaternary amine, to penetrate the blood-brain barrier is limited. This allows the action of methylnaltrexone in the gastrointestinal tract tissues, without the effect of analgesic opiates on o.u.n. Methylnaltrexone bromide absorbed quickly and reaches Cmax approximately 0.5 h after subcutaneous administration. Cmax and AUC increases with increasing dose from 0.15 mg / kg to 0.5 mg / kg in a dose-proportional manner. The absolute bioavailability of a 0.30 mg / kg subcutaneous dose versus a 0.30 mg / kg intravenous dose is 82%. Methylnaltrexone bromide minimally binds to human plasma proteins (11.0-15.3%). In humans, methylnaltrexone is metabolised to a small extent to methyl-6-natrexol isomers and methylnaltrexone sulfate. Methylaltrexone is excreted as an unchanged active substance; about half of the dose is excreted in the urine and a little less in the feces. Final T0,5 is about 8 hours.
Contraindications:
Hypersensitivity to the components of the preparation. The use of methylnaltrexone bromide is contraindicated in patients with known or suspected mechanical intestinal obstruction or requiring surgical intervention symptoms of an acute abdomen.
Precautions:
Methylnaltrexone should not be used to treat patients with constipation not related to the use of opioids. Patients who experience severe or persistent diarrhea during treatment should be advised to discontinue use. Clinical trials for methylnaltrexone bromide have not been conducted for more than 4 months, so it can only be used for a limited time. It should only be used in patients who are receiving palliative care. The product is used in addition to the usual laxatives. It must not be administered to patients with severe hepatic impairment or end stage renal failure requiring dialysis. Methylnaltrexone bromide has not been studied in patients with colostomy, peritoneal catheter, active diverticulitis, faecal stones. Therefore, it is recommended that the preparation be used with caution in these patients. There is no experience in children under 18 years of age, therefore methylnaltrexone should not be used in the pediatric age group until further data becomes available.
Pregnancy and lactation:
There are no adequate data from the use of methylnaltrexone bromide in pregnant women. It must not be used during pregnancy unless clearly necessary. It is not known whether methylnatoxone bromide passes into breast milk. The decision regarding the continuation / interruption of breastfeeding or continuation / discontinuation of treatment with the product should be taken taking into account the benefits of breastfeeding for the child and the benefits of treatment with the preparation for women.
Side effects:
The most common drug-related adverse reactions in all patients treated with methylnaltrexone bromide were abdominal pain, nausea, diarrhea and bloating. Common: dizziness and disorders at the injection site (eg stinging, burning, pain, redness, swelling).
Dosage:
Adults: the recommended dose is 8 mg (0.4 ml) for patients weighing 38-61 kg or 12 mg (0.6 ml) for patients weighing 62-114 kg. The standard application schedule is one single dose administered every other day. Doses may also be administered at longer intervals, depending on clinical need. Patients may receive two consecutive doses 24-hour apart only if there was no response (emptying) to the dose received the previous day. Dosing in patients with a body weight outside the range should be 0.15 mg / kg. The injection volume for these patients should be calculated as follows: Dose (ml) = patient's body weight (kg) x 0.0075. In patients with severe renal impairment (creatinine clearance <30 ml / min), the dose should be reduced from 12 mg to 8 mg (0.4 ml) for patients weighing 62-114 kg or 0.15 mg / kg to 0.075 mg / kg for patients with a body weight outside the range of 62-114 kg. There are no data on patients on dialysis for end-stage renal failure, therefore the use of these patients is not recommended.
(C)
