Tuesday, May 10, 2011

The Flaws in One-Size-Fits-All Dosing

 It is about time! I have wondered about this topic for decades! This seems so obvious a consideration! Is it due to--for lack of a better term--laziness, on the part of prescribers? Too much trouble to punch some numbers into a calculator, then round to the nearest available dosage?
A subscriber to our Health After 50 newsletter asks: I'm taller and heavier than the average person. Should I be taking a higher dose of antibiotics? ... as an editorial in The Lancet recently pointed out, a 6- foot, 198-pound male with pneumonia will likely be prescribed the same dose of antibiotics as a 5- foot, 123-pound woman. Some research suggests that one-size-fits-all dosing of antibiotics poses a distinct disadvantage for heavier people. Why? Large -- especially obese -- people have comparatively larger blood volumes than their normal-weight counterparts. Consequently, the concentration of an antibiotic in the bloodstream is lower in a large, obese individual than in a smaller one, making it harder for the antibiotic to fight infection. In fact, some experts theorize that insufficient dosing relative to body size may help explain why obese people tend to recover poorly from infections. Insufficient dosing may also push physicians to prescribe more antibiotics for longer durations, thus contributing to the alarming trend of antibiotic resistance. Ideally, antibiotics should be individualized to age, gender and liver and kidney function as well as height and weight. But clinical trials on individualized dosing have yet to be conducted. It's not clear if this would be cost effective, as drug manufacturers would also have to make changes to match individual patients' needs. For now, talk to your doctor about upping your dose if your current one isn't helping


  1. As a pharmacist I have to weigh (HAHA....large people, large dosing) in on this issue.....Ideally this is the way it should work: Physicians diagnose disease/illness, pharmacists choose the medication AND dose it appropriately. This is what we are trained to do and have 6+ years of education, board certifications, yada yada. Of course pharmacists need to be paid for this clinical work and the way our health care system reimburses only for product (drug) and not clinical skill/time does not allow pharmacists the time or system to do this effectively at Walgreens/CVS etc.

    I have chosen to work in a hospital because I do this kind of stuff all day long and don't have to worry about people's wretched copays, prior auth's etc that my counterparts in the retail world have to deal with......

  2. Ah, I am very honored to have a veteran pharmacist weigh in, Marta! This makes too much sense to me!