Additional investigation on the potentiation of phenytoin teratogenicity by fluconazole

Antifungal medication use during early pregnancy and the risk of congenital heart defects in the National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Fungal infections are common among pregnant people. Recent studies suggest positive associations between oral antifungals used to treat fungal infections and congenital heart defects (CHDs).

METHODS

We estimated associations between first trimester antifungal use and 20 major, specific CHDs using data from the National Birth Defects Prevention Study (NBDPS), a multi-site, case-control study that included pregnancies with estimated delivery dates from October 1997 through December 2011. Infants with CHDs ("cases") were ascertained from 10 birth defect surveillance programs. Live born infants without major birth defects ("controls") were randomly selected from birth records or hospital discharge lists. First trimester antifungal use was self-reported via maternal interview. We estimated adjusted odds ratios (AORs) and 95% confidence intervals (CIs) using logistic regression with Firth's penalized likelihood.

RESULTS

First trimester antifungal use was reported by 148/11,653 (1.3%) case and 123/11,427 (1.1%) control participants. We estimated AORs for 12 CHDs; six had AORs >1.5 (tetralogy of Fallot, double outlet right ventricle with transposition of the great arteries [DORV-TGA], atrioventricular septal defect, hypoplastic left heart syndrome, pulmonary atresia, muscular ventricular septal defect), and one (pulmonary valve stenosis) had an AOR <0.7. All CIs included the null, except for DORV-TGA.

CONCLUSIONS

First trimester antifungal use was rare. We observed some positive associations for several specific CHDs in our analysis, although the CIs largely included the null. Results do not support a large increase in risk, but smaller increases in risk for certain CHD cannot be ruled out.

The safety of oral fluconazole during the first trimester of pregnancy: a systematic review and meta-analysis

BACKGROUND

Oral fluconazole is used to treat vulvovaginal candidiasis during pregnancy. However, there are concerns regarding the pregnancy outcomes following exposure to fluconazole.

OBJECTIVES

To evaluate the pregnancy outcomes associated with exposure to oral fluconazole during the first trimester of pregnancy.

SEARCH STRATEGY

A systematic literature search was conducted to identify relevant studies published from inception until April 2019.

SELECTION CRITERIA

Relevant English-language citations using the terms oral fluconazole and pregnancy in humans.

DATA COLLECTION

Two reviewers independently abstracted data and assessed study quality.

MAIN RESULTS

Oral fluconazole use during the first trimester of pregnancy was marginally associated with an increased risk of congenital malformations (odds ratio [OR] 1.09, 95% CI 0.99-1.2, P = 0.088; n = 6 studies), whereas in the subgroup analysis, this association existed only for high-dose users (>150 mg) (OR 1. 19, 95% CI 1.01-1.4, P = 0.039; n = 2). Exposure to fluconazole also increased the risk of heart malformations (OR 1.31, 95% CI 1.09-1.57, P = 0.003; n = 4), cardiac septal defects (OR 1.3, 95% CI 1.1-1.67, P = 0.047; n = 3), and tetralogy of Fallot (OR 3.39 95% CI 1.71-6.74, P < 0.001; n = 2) in the offspring. In addition, exposure to fluconazole was significantly associated with an increased risk of spontaneous abortion (OR 1.99, 95% CI 1.38-2.88, P < 0.001; n = 3).

CONCLUSIONS

Oral fluconazole use during the first trimester of pregnancy appears to be associated with heart malformations and spontaneous abortion, but a causal link cannot be proven.

TWEETABLE ABSTRACT

Oral fluconazole during the first trimester of pregnancy may be associated with unfavourable pregnancy outcomes.

Design and synthesis of new fluconazole analogues

The synthesis of new fluconazole analogues containing two different 1,2,3-triazole units and an amide group is described. All the compounds showed very high antifungal activity and no toxicity.

Teratogenic effects in mouse fetuses subjected to the concurrent in utero exposure to miconazole and metronidazole

The potential interactivity of the antimicrobials miconazole and metronidazole in the induction of teratogenic effects was investigated in the present study. Drugs were injected at 60 mg/kg either individually or in combination to pregnant mice on gestation day (GD) 8, 9, or 10. Teratological assessments were carried out on GD 18. A potent teratogenic interaction resulted from miconazole-metronidazole co-administration, causing an increment in axial skeletal defects incidence. While, the individual exposure to miconazole or metronidazole produced axial skeletal defects at frequencies that did not exceed 5.6% in the various treatment groups, the percentage of fetuses with malformed skeleton reached 26% after co-exposure on GD 8 or GD 9. No significant synergism was noted when drugs were co-administered on GD 10. This study shows that a teratogenic interaction can result from miconazole-metronidazole concomitant exposure.

Increased Susceptibility to Phenytoin Teratogenicity: Excessive Generation of Reactive Oxygen Species or Impaired Antioxidant Defense?

Phenytoin is a human and animal teratogen. Accumulating evidence suggests that the teratogenicity is associated with a potential of phenytoin to cause embryonic cardiac arrhythmia and resultant generation of toxic reactive oxygen species via hypoxia-reoxygenation mechanisms. The A/J mouse is more susceptible to phenytoin teratogenicity than other mouse strains. The aim of this study was to investigate whether A/J mice have other antioxidant enzyme activities than C57BL/6J and CD-1 mice. Also, strain differences in phenytoin effects on embryonic heart rate and rhythm were determined. Another objective was to determine whether a spin trapping agent with capacity to capture reactive oxygen species alter the developmental toxicity of phenytoin. Treatment with this agent resulted in a marked decrease in phenytoin teratogenicity, which supports the idea that reactive oxygen species are important mediators for the teratogenic action of phenytoin. The A/J mice embryos were most susceptible to the adverse cardiac effects of phenytoin and had the highest activity of superoxide dismutase and glutathione peroxidase, while the activity of catalase was the same in embryos of the three different strains. The high activities of antioxidant enzymes in the A/J stain indicate that the sensitivity to develop malformations is caused by excessive arrhythmia-related generation of reactive oxygen species rather than impaired antioxidant defense.

Postulated pathogenic pathway in triazole fungicide induced dysmorphogenic effects

Triazole fungicides are used in medicine as well as in agricultural treatment of mycoses. The pharmacological mechanism is related to the inhibition of CYP enzymes involved in the formation of the fungal walls. A similar inhibition of human CYP enzymes has been suggested as the cause of triazole side effects in humans. An important role of some CYP isoforms (CYP26 isoforms) expressed during mammalian development is the catabolism of retinoic acid, a known morphogen in vertebrates and invertebrates. The adverse effects on morphogenesis, observed after exposure of mammalian, amphibian and ascidiacea, are compared to the reported effects of triazole in humans. The possible pathogenic pathway in triazole-related teratogenesis is discussed on the basis of different experimental approaches.