Epidemiological studies comparing combined oral contraceptives found that pills containing which progestogen carry a higher risk of venous thromboembolism than those containing levonorgestrel?
- A Desogestrel ✓
- B Norgestimate
- C Norethisterone
- D Norethindrone acetate
Correct answer: A. Desogestrel
Explanation
Third-generation progestins (desogestrel, gestodene) were developed to improve lipid profiles by reducing androgenicity, but studies showed roughly a two-fold higher venous thromboembolism risk compared with second-generation levonorgestrel-containing pills at the same oestrogen dose. The proposed mechanism involves greater acquired resistance to activated protein A. Norethisterone and norethindrone acetate are first-generation progestins, and norgestimate is metabolised largely to levonorgestrel, so they do not carry this excess risk.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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