Risk of venous thromboembolism from use of Dienogest: Experimental study on Rats

Oral contraceptive pills are widely used and most popular pharmacological approaches for contraception. Most of oral contraceptive pills are available for public use as an over-the-counter-medication. The availability and easy access make users more prone to adverse drug effects. The combined pills are either progesterone alone or combined with estradiol to reduce the imbalance-associated impact of estrogen/progesterone level in the blood. Progesterone fall into four generations (first, second, third, and fourth), with reports that venous thromboembolism (VTE) greatly associated with the newer generation. We aimed to identify the effects of dienogest on inducing thromboembolism in rats following exposure to dienogest for a period of either 10 days (2 estrus cycles), 20 days (4 estrous cycles), 30 days (6 estrus cycles). To do so, 40 rats were divided into 4 grous; dienogest-free control group, dienogest treated for 10 days (G1), 20 days (G2), and 30 days (G3). Then lungs and femur veins are collected from subjects after sacrificing them and these tissues are fixed for histological analysis. Results has confirmed that venous thromboembolism increased with dienogest therapy indicated by increased score of inflammation in lung tissues alongside increased thickness of femur venous and histological findings of fibrin deposition, vessel congestion, inflammatory cells infiltrations, and epithelial desquamation. To sum up, dienogest long term therapy could be a risk for cardiac thrombotic diseases and therefore we do advice use alternative progesterone or add estrogen low dose to minimize toxic effects primarily when use as postmenopausal replacement therapy. Keywords: thrombosis, lung, vein, Dienogest, contraceptives.