a) Selective Estrogen Receptor Modulators (SERMs)
Tissue-selective drugs that act as estrogen agonists in some tissues and antagonists in others, depending on the local receptor conformation and co-regulator proteins present. Examples: Tamoxifen — antagonist in breast tissue (used in ER-positive breast cancer), partial agonist in the endometrium (raising endometrial cancer risk) and bone. Raloxifene — antagonist in breast and endometrium (avoiding tamoxifen’s endometrial risk), agonist in bone (used for postmenopausal osteoporosis prevention/treatment). Clomiphene — antagonist at the hypothalamus, used to induce ovulation in anovulatory infertility.
b) Treatment of diabetic ketoacidosis
IV fluids — isotonic saline initially, to correct dehydration and improve tissue perfusion, transitioning to dextrose-containing fluids once blood glucose falls to a target range (to allow continued insulin therapy without hypoglycemia).
IV regular (short-acting) insulin infusion — corrects hyperglycemia and, critically, halts ketogenesis by suppressing lipolysis; given as a continuous low-dose infusion rather than a large bolus, to avoid overly rapid osmotic shifts.
Potassium replacement — total body potassium is depleted despite a normal/high initial serum level (insulin and correction of acidosis drive potassium intracellularly); replacement is started once urine output is confirmed and serum potassium is not significantly elevated, to prevent dangerous hypokalemia as insulin therapy proceeds.
Correction of the precipitating cause (infection, missed insulin doses) and, if severe acidosis with hemodynamic compromise, cautious bicarbonate — reserved for severe cases only, given risks of overcorrection.
