Prenatal and developmental toxicity study of meclizine and caffeine combination in female albino Wistar rats.

Meclizine and caffeine combination is used for the treatment of morning sickness. Both compounds are teratogenic and caffeine is known to possess anti-fertility activity also. The present study was undertaken to evaluate the reproductive toxic effect of meclizine and caffeine combination. Three doses were taken for the study; low dose (LD; meclizine 3.7 mg/kg and caffeine 3 mg/kg) was selected from commercially available formulation, middle dose (MD; meclizine 37 mg/kg and caffeine 30 mg/kg) and high dose (HD; meclizine 370 mg/kg and caffeine 300 mg/kg). The mixture was administered 1-7 days and 8-14 days for fertility and embryotoxic studies respectively. Laparotomy was done on 10t day of gestation period. Number of implants and corpora lutea were counted, pre and post-implantation losses were determined. In embryo toxicity study fetuses were evaluated for external, skeletal and visceral examination. High dose was removed from both fertility and embryotoxicity studies due to its severe toxicity to the dam. Significant anti-fertility activity was observed at middle dose. Embryotoxicity study showed significant reduction in fetal body weight, body length and body mass index, dam body weight gain on gestation day 14. Absolute kidney weight in MD and absolute and relative spleen weight in both LD and MD were significantly reduced. There was no increase in external or internal congenital anomalies at both LD and MD. The, results suggest that prescription of meclizine and caffeine for morning sickness in early pregnancy should be reviewed carefully.