Methylnaltrexonii bromidum
Description
Peripheral opioid receptor antagonists; methylnaltrexone
bromide is a selective antagonist of opioid binding
to ? receptors, 8 times weaker
affects ? opioid receptors and has much
lower affinity for ? opioid receptors.
Indications
Treatment of opioid-induced constipation
in patients with advanced illness receiving
palliative care, if the response to
conventional laxatives was inadequate.
Contraindications
Hypersensitivity to the active substance or any excipient. Patients diagnosed with
or suspected of having mechanical obstruction of the gastrointestinal tract
or acute surgical abdominal condition should not be treated
with methylnaltrexone bromide.
Dosage
For adults. Inj. s.c. Recommended dose – 8 mg
(for patients weighing 38–61 kg) or 12 mg
(for patients weighing 62–114 kg). Allowed
1 dose every other day.
For children. Data is not available. No experience in using
methylnaltrexone bromide in children under
18 years old. Therefore, methylnaltrexone
bromide should not be used in children and adolescents
until more data is obtained.
For elderly patients. No need to adjust doses based on age.
Renal impairment. For patients with severe renal
impairment (creatinine clearance < 30 ml/
min.), the dose of methylnaltrexone bromide, calculated
in mg/kg, should be reduced by 50%. There is no data on
patients with end-stage renal disease
undergoing hemodialysis; it is not recommended to use
in these patients.
Hepatic impairment. For patients with mild or
moderate hepatic impairment,
no dose adjustment is needed, and for those with
severe hepatic impairment (Child-Pugh C
class), use is not recommended.
Adverse reactions
Most common: abdominal pain, nausea, diarrhea
and flatulence; dizziness; reactions
at the injection site (e.g., redness, burning,
pain, swelling), excessive sweating.
Pregnancy
Should not be used during pregnancy, except in clearly
necessary cases.
Breastfeeding
When deciding whether to continue or discontinue breastfeeding
or treatment, the benefits of breastfeeding
for the infant and the benefits of treatment for the mother should be considered.
Warnings
Patients with gastrointestinal tract damage
or suspected of such damage should be treated with caution.
Patients with opioid-unrelated constipation should not be treated.
If severe or persistent
diarrhea occurs during treatment, patients should be advised
to discontinue treatment and consult their doctor.
Should be administered only to patients receiving palliative care.
Not recommended for patients with severe hepatic impairment
or end-stage renal disease requiring dialysis. Methylnaltrexone
bromide should be administered with caution to patients
with a colostomy or intra-abdominal
catheter; those suffering from active diverticulitis
or constipation.
Source | Drug Guide | Lithuanian University of Health Sciences | Institute of Physiology and Pharmacology | Doctor of Medical Sciences Rimas Jankūnas, Doctor of Medical Sciences Arvydas Milašius | Clinic of Internal Diseases | Doctor of Medical Sciences Palmira Leišytė