A 29-year-old woman starts a combined oral contraceptive containing ethinylestradiol and drospirenone. Which laboratory parameter should be monitored because of a property unique to drospirenone among commonly used progestins?

• A Serum sodium
• B Serum potassium ✓
• C Fasting blood glucose
• D Serum triglycerides

Explanation

Drospirenone is an analogue of spironolactone with antimineralocorticoid activity; it promotes sodium loss and potassium retention. Hyperkalaemia is the characteristic concern, especially with renal impairment or concurrent ACE inhibitors, ARBs, or potassium-sparing diuretics. Other progestins lack mineralocorticoid antagonism, so potassium monitoring is specific to drospirenone-containing pills.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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