Evaluation of developmental toxicity of guaifenesin using pregnant female rats.

OBJECTIVES: Guaifenesin possesses expectorant, muscle relaxant, and anticonvulsive properties. To the best of our knowledge, the promising data regarding the developmental toxicity of guaifenesin are scarce. The current study investigates the developmental toxic effects of guaifenesin in detail using female rats.

MATERIALS AND METHODS: Twenty-five dams were divided into five groups. Group 1 served as a control, while Group-2, -3, -4, and -5 were administered with 250, 350, 500, and 600 (mg/kg b.w.) doses of guaifenesin, respectively, starting from gestation day 6 to day 17. Half of the total recovered fetuses was subjected to morphologic and morphometric analysis, while other half was subjected to skeletal examination.

RESULTS: A significant reduction in maternal weight, and food/water intake, was observed, however, no mortality and morbidity were observed. About 14 dead fetuses were found in Group-3 and -4 each, while 26 in Group 5. Morphological analysis revealed 21.2%, 45.4%, 67.2%, and 86.9% of total fetuses having hemorrhagic spots in Group-2, -3, -4, and -5, respectively. Dropping wrist/ankle and kinky tail were found in Group-4 and -5 only. Morphometric analysis showed a significant decline in fetal weight, full body length, skull length, forelimb length, hindlimb length, and tail length in all guaifenesin treated groups. Skeletal examination displayed that only Group 5 fetuses had increased intercostal space between 7(th) and 8(th) rib. We also observed improper development of carpals, metacarpals, tarsals, and metatarsals of the Group 5 fetuses.

CONCLUSION: Guaifenesin showed a significant developmental toxicity at selected test doses; therefore, a careful use is suggested during pregnancy.