, nalbuphine, butorphanol, or buprenorphine) may reduce the analgesic effect of OPANA ER or may precipitate withdrawal symptoms in these patients. Avoid the use of mixed agonist/antagonist analgesics in patients receiving OPANA ER.
7.4 Cimetidine
Cimetidine can potentiate opioid-induced respiratory depression. Monitor patients for respiratory depression when OPANA ER and cimetidine are used concurrently.
7.5 Anticholinergics
Anticholinergics or other medications with anticholinergic activity when used concurrently with opioid analgesics may result in increased risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor patients for signs of respiratory and central nervous system depression when OPANA ER is used concurrently with anticholinergic drugs.
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
The safety of using oxymorphone in pregnancy has not been established with regard to possible adverse effects on fetal development. The use of OPANA ER in pregnancy, in nursing mothers, or in women of child-bearing potential requires that the possible benefits of the drug be weighed against the possible hazards to the mother and the child.
Prolonged use of opioid analgesics during pregnancy may cause fetal-neonatal physical dependence.
Teratogenic Effects (Pregnancy Category C)
There are no adequate and well-controlled studies of oxymorphone in pregnant women. OPANA ER should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus [see Use in Specific Populations (8.2)].
Oxymorphone hydrochloride administration did not cause malformations at any doses eva luated during developmental toxicity studies in rats (≤25 mg/kg/day) or rabbits (≤50 mg/kg/day). These doses are ~3-fold and ~12-fold the human dose of 40 mg every 12 hours, based on body surface area. There were no developmental effects in rats treated with 5 mg/kg/day or rabbits treated with 25 mg/kg/day. Fetal weights were reduced in rats and rabbits given doses of ≥10 mg/kg/day and 50 mg/kg/day, respectively. These doses are ~1.2-fold and ~12-fold the human dose of 40 mg every 12 hours based on body surface area, respectively. There were no effects of oxymorphone hydrochloride on intrauterine survival in rats at doses ≤25 mg/kg/day, or rabbits at ≤50 mg/kg/day in these studies (see Non-teratogenic Effects, below). In a study that was conducted prior to the establishment of Good Laboratory Practices (GLP) and not according to current recommended methodology, a single subcutaneous injection of oxymorphone hydrochloride on gestation day 8 was reported to produce malformations in offspring of hamsters that received 15.5-fold the human dose of 40 mg every 12 hours based on body surface area. This dose also produced 20% maternal lethality.
Non-teratogenic Effects
Oxymorphone hydrochloride administration to female rats during gestation in a pre- and postnatal developmental toxicity study reduced mean litter size (18%) at a dose of 25 mg/kg/day, attributed to an increased incidence of stillborn pups. An increase in neonatal death occurred at ≥5 mg/kg/day. Post-natal survival of the pups was reduced throughout weaning following treatment of the dams with 25 mg/kg/day. Low pup birth weight and decreased postnatal weight gain occurred in pups born to oxymorphone-treated pregnant rats given |
