Public Health · single question
A drug with LOW LD50 and HIGH ED50 has a:
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Correct answer: C. Low therapeutic index u2014 very dangerous
TI = LD50/ED50. Low LD50 (numerator) u00f7 High ED50 (denominator) = LOW TI. A low TI means the drug has a NARROW safety margin u2014 the effective dose is dangerously close to the lethal dose. Classic narrow-TI drugs: warfarin, lithium, digoxin, phenytoin.