Question explored with the scientific record
Naldemedine and pregnancy
The short version: no study in this retrieval tested naldemedine in pregnant women, so its safety in pregnancy is unestablished, not proven.
Naldemedine is a peripherally acting mu-opioid receptor antagonist, a drug that stays largely outside the brain and blocks opioid receptors in the gut to relieve opioid-induced constipation [1][2]. The trials that support it are in non-pregnant adults with chronic pain. COMPOSE-1 and COMPOSE-2 randomized 547 and 553 patients and measured bowel-movement response rates, not pregnancy outcomes [1]. A network meta-analysis of 27 trials and 9,149 participants ranked naldemedine among the more effective agents for that constipation [3]. None of these trials enrolled pregnant women, and none reported fetal outcomes.
That absence is the whole story here. The retrieval contains no pharmacokinetic study of naldemedine in pregnancy, no animal developmental-toxicity study of naldemedine, and no registry or cohort data on first-trimester exposure. The pregnancy records that did surface are about other drugs and conditions entirely, so they cannot be stretched to cover this one. What the evidence does show is that pregnancy changes how many drugs are handled: clearance and blood levels shift substantially for several medications during gestation [4][5][6]. Whether naldemedine follows that pattern is unknown from these records.
| What is known | Status in this retrieval |
|---|---|
| Works for opioid constipation in non-pregnant adults | Supported by RCTs [1][3] |
| Human pregnancy safety data | None retrieved |
| Animal fetal toxicity data for naldemedine | None retrieved |
| Altered drug handling in pregnancy (other drugs) | Documented [4][5][6] |
My call: for a pregnant woman, naldemedine's safety is not established by anything here, and the burden sits on whoever would prescribe it to show the fetal data. Confidence: low, because the retrieval is thin on this exact drug in pregnancy.
Sources used 6
-
Naldemedine versus placebo for opioid-induced constipation (COMPOSE-1 and COMPOSE-2): two multicentre, phase 3, double-blind, randomised, parallel-group trials
This study demonstrates that naldemedine, a peripherally acting μ-opioid receptor antagonist, significantly improves bowel movement frequency and symptoms in patients with opioid-induced constipation compared to placebo, while being generally well tolerated.
DOI: 10.1016/S2468-1253(17)30105-X -
Medical Management of Opioid-Induced Constipation
This 2019 JAMA guideline reviews randomized trial evidence to guide medical management of opioid-induced constipation (OIC), endorsing traditional laxatives as first-line therapy and peripherally acting μ-opioid receptor antagonists (PAMORAs) such as naldemedine and naloxegol fo…
DOI: 10.1001/jama.2019.15852 -
Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: systematic review and network meta-analysis
This study systematically reviews and performs a network meta-analysis of pharmacological therapies for opioid-induced constipation (OIC) in adults, showing naloxone and naldemedine as top performers for efficacy (with naloxone generally safest), across 27 randomized controlled …
DOI: 10.1136/gutjnl-2018-316001 -
Total and unbound darunavir pharmacokinetics in pregnant women infected with HIV ‐1: results of a study of darunavir/ritonavir 600/100 mg administered twice daily
This study evaluates the pharmacokinetics of darunavir/ritonavir in HIV-1-infected pregnant women, finding that total darunavir exposure decreases during pregnancy while unbound darunavir remains stable, suggesting no dose adjustment is necessary.
DOI: 10.1111/hiv.12047 -
Influence of Body Weight, Ethnicity, Oral Contraceptives, and Pregnancy on the Pharmacokinetics of Azithromycin in Women of Childbearing Age
Population pharmacokinetic analysis of azithromycin in pregnant and nonpregnant women, revealing ethnicity- and pregnancy-driven changes in clearance and exposure that suggest dose considerations for non-African American pregnant women and oral contraceptive users.
DOI: 10.1128/aac.00717-11 -
Pregnancy-Related Effects on Lamivudine Pharmacokinetics in a Population Study with 228 Women
This study investigates the pharmacokinetics of lamivudine in HIV-infected pregnant and nonpregnant women, revealing that pregnant women exhibit a 22% higher clearance rate without requiring dosage adjustments.
DOI: 10.1128/AAC.00370-11