Teratogenic and cytogenetic effects of ivermectin and its interaction with P-glycoprotein inhibitor

Res Vet Sci. 2011 Feb;90(1):116-23. doi: 10.1016/j.rvsc.2010.05.020. Epub 2010 Jun 25.


Experiments in animals proved that P-glycoprotein (Pgp) forms a functional barrier between maternal and fetal blood circulation in the placenta, thus protecting the fetus from exposure to xenobiotics during pregnancy. In this study we aimed to demonstrate the effects of administration of ivermectin (anthelmentic drug, Pgp substrates), either alone or simultaneously with verapamil (Pgp inhibitor) in Wister rats on fetal development, maternal bone marrow for detection of micronuclei (MN), chromosomal aberrations and mitotic index (MI) and embryonic liver cells for cellular proliferation indicated by MI, and bleeding from umbilical vessels for detection of embryonic micronuclei (MN). The results revealed that administration of ivermectin or verapamil at 6th through 15th day of gestation did not significantly altered fetal development. While, co-administration of ivermectin and verapamil clearly disturbed fetal development as indicated from abnormal feto-maternal attachment and a significant decrease in fetal weights and numbers. Furthermore, co-administration of both drugs induced a significant increase in resorption sites, post-implantation loss and external, visceral and skeletal abnormalities. They also induced genotoxicity in both dam and embryonic cells indicated by reduced mitotic index, increased number of micronucleated erythrocytes in both, and increased different types of chromosomal aberrations in dam cells, while ivermectin alone show some genotoxic effect on somatic cells of dams and the embryos. Verapamil induced reduction of embryonic mitotic index. We concluded combined treatment of ivermectin and verapamil severely affect fetal genetic material and development and induced genotoxic effect in somatic cells of the dams.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B / antagonists & inhibitors*
  • Animals
  • Anthelmintics / toxicity*
  • Bone Marrow / drug effects
  • Bone Marrow Cells / drug effects
  • Cell Proliferation
  • Chromosome Aberrations / chemically induced
  • Drug Interactions
  • Female
  • Hepatocytes / drug effects
  • Ivermectin / toxicity*
  • Male
  • Micronuclei, Chromosome-Defective / chemically induced
  • Pregnancy
  • Rats
  • Rats, Wistar
  • Teratogens / toxicity
  • Umbilical Veins
  • Uterus
  • Verapamil / pharmacology*


  • ATP Binding Cassette Transporter, Subfamily B
  • Anthelmintics
  • Teratogens
  • Ivermectin
  • Verapamil