07/30/2026
๐ The NAPLEX calculation you'll use more than any other โ and its classic trap.
Female patient, 60 years old, 72 kg, serum creatinine 1.0. What's her creatinine clearance?
Run Cockcroft-Gault: (140 โ 60) ร 72 รท (72 ร 1.0) = 80. Almost done โ but she's female, so multiply by 0.85. Answer: 68 mL/min.
That 0.85 is where people lose the point. Skip it and you get 80, which overestimates her kidney function โ and that can mean dosing a renally cleared drug too high.
Two rules to bank:
๐ฉ Female? Multiply by 0.85, every time.
โ๏ธ Obese (BMI โฅ30)? Use adjusted body weight, not actual.
๐ Save this and tag someone grinding NAPLEX calcs!
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