Risk Summary
Use of NSAIDs, including Diclofenac Potassium Capsules, can cause premature closure of the fetal ductus arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. Because of these risks, limit dose and duration of Diclofenac Potassium Capsules use between about 20 and 30 weeks of gestation, and avoid Diclofenac Potassium Capsules use at about 30 weeks of gestation and later in pregnancy
(see Clinical Considerations, Data).
Premature Closure of Fetal Ductus Arteriosus
Use of NSAIDs, including Diclofenac Potassium Capsules, at about 30 weeks gestation or later in pregnancy increases the risk of premature closure of the fetal ductus arteriosus.
Oligohydramnios/Neonatal Renal Impairment
Use of NSAIDs at about 20 weeks gestation or later in pregnancy has been associated with cases of fetal renal dysfunction leading to oligohydramnios, and in some cases, neonatal renal impairment.
Data from observational studies regarding other potential embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive.
In animal reproduction studies, no evidence of malformations was observed in mice, rats, and rabbits given diclofenac during the period of organogenesis at doses up to approximately 1, 1, and 2 times, respectively, the maximum recommended human dose (MRHD) of Diclofenac Potassium Capsules, despite the presence of maternal and fetal toxicity at these doses. In published studies, administration of clinically relevant doses of diclofenac to pregnant rats produced adverse effects on brain, kidney, and testicular development
[see Data]. Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as diclofenac, resulted in increased pre- and post-implantation loss. Prostaglandins also have been shown to have an important role in fetal kidney development. In published animal studies, prostaglandin synthesis inhibitors have been reported to impair kidney development when administered at clinically relevant doses.
The estimated background risk of major birth defects and miscarriage for the indicated population(s) is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
Clinical Considerations
Fetal/Neonatal Adverse Reactions
Premature Closure of Fetal Ductus Arteriosus:
Avoid use of NSAIDs in women at about 30 weeks gestation and later in pregnancy, because NSAIDs, including Diclofenac Potassium Capsules, can cause premature closure of the fetal ductus arteriosus
(see Data).
Oligohydramnios/Neonatal Renal Impairment:
If an NSAID is necessary at about 20 weeks gestation or later in pregnancy, limit the use to the lowest dose and shortest duration possible. If Diclofenac Potassium Capsules treatment extends beyond 48 hours, consider monitoring with ultrasound for oligohydramnios. If oligohydramnios occurs, discontinue Diclofenac Potassium Capsules and follow up according to clinical practice
(see Data).
Labor or Delivery
There are no studies on the effects of Diclofenac Potassium Capsules during labor or delivery. In animal studies, NSAIDS, including diclofenac, inhibit prostaglandin synthesis, cause delayed parturition, and increase the incidence of stillbirth.
Data
Human Data
Premature Closure of Fetal Ductus Arteriosus:
Published literature reports that the use of NSAIDs at about 30 weeks of gestation and later in pregnancy may cause premature closure of the fetal ductus arteriosus.
Oligohydramnios/Neonatal Renal Impairment:
Published studies and postmarketing reports describe maternal NSAID use at about 20 weeks gestation or later in pregnancy associated with fetal renal dysfunction leading to oligohydramnios, and in some cases, neonatal renal impairment. These adverse outcomes are seen, on average, after days to weeks of treatment, although oligohydramnios has been infrequently reported as soon as 48 hours after NSAID initiation. In many cases, but not all, the decrease in amniotic fluid was transient and reversible with cessation of the drug. There have been a limited number of case reports of maternal NSAID use and neonatal renal dysfunction without oligohydramnios, some of which were irreversible. Some cases of neonatal renal dysfunction required treatment with invasive procedures, such as exchange transfusion or dialysis.
Methodological limitations of these postmarketing studies and reports include lack of a control group; limited information regarding dose, duration, and timing of drug exposure; and concomitant use of other medications. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal NSAID use. Because the published safety data on neonatal outcomes involved mostly preterm infants, the generalizability of certain reported risks to the full-term infant exposed to NSAIDs through maternal use is uncertain.
Diclofenac has been shown to cross the placental barrier in humans.
Animal data
Reproductive and developmental studies in animals demonstrated that diclofenac sodium administration during organogenesis did not produce malformations despite the induction of maternal toxicity and fetal toxicity in mice at oral doses up to 20 mg/kg/day (approximately equivalent to the maximum recommended human dose [MRHD] of Diclofenac Potassium Capsules, 100 mg/day, based on body surface area (BSA) comparison), and in rats and rabbits at oral doses up to 10 mg/kg/day (approximately 1 and 2 times, respectively, the MRHD based on BSA comparison).
In a study in which pregnant rats were orally administered 2 or 4 mg/kg diclofenac (0.2 and 0.4 times the MRHD based on BSA comparison) from Gestation Day 15 through Lactation Day 21, significant maternal toxicity (peritonitis, mortality) was noted. These maternally toxic doses were associated with dystocia, prolonged gestation, reduced fetal weights and growth, and reduced fetal survival. Diclofenac has been shown to cross the placental barrier in mice and rats.
In published studies, diclofenac administration to pregnant rats prolonged gestation and produced liver toxicity and neuronal loss in offspring (1 mg/kg, IP; 0.1 times the MRHD based on BSA comparison), impaired nephrogenesis in the kidney (3.6 mg/kg, IP; 0.3 times the MRHD based on BSA comparison), and caused adverse effects on the developing testes (6.1 mg/kg, PO; 0.6 times the MRHD based on BSA comparison).