credit: medicaldaily.com
How does a parent measure a dose of liquid medicine for her child when the label says, give child ¾ teaspoonful by mouth twice a day for 5 days ? This was the real-life example used in a report by the journal, Pediatrics, and featured on NBC News the other day. The medicine, Tamiflu in this case, was accompanied by an oral syringe, but the syringe was calibrated in milliliters. And just to make the problem even more confusing, the medicine box also carried the marking for this “oral suspension” of “12 mg/mL”. That has only to do with the concentration of the medicine, of course, not the dosage size. (The abbreviation mL is also used for milliliter.)
The basic problem here is, I think, what used to be a matter of convenience has now become a problem. For many years, liquid medicine came without any kind of measuring device, but every kitchen had a spoon. In the above case an oral syringe was supplied but, unfortunately, it was calibrated in milliliters (thousandths of a Liter) and the dosage was in teaspoons.
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Anyone knows that spoons vary widely in shape and depth, whereas a milliliter is a milliliter. It is far past time, I submit, that the United States finally adopt the metric system. (We would be the last industrialized nation on earth to do so.)
Medicinal measurements in the metric system are easy, once one gets familiar with them. I thought it might be fun to review them. Here’s a practical summary:
Length
A meter is about 3 inches longer than a yard.
A centimeter is one-one hundredth of a meter. There are about 2.5 of them in an inch.
A millimeter is one-one thousandth of a meter, or a tenth of a centimeter. There are about 25 of them in an inch.
Volume and Weight
A liter is the volume of a kilogram of water and is about 5% bigger than a quart.
A milliliter is a cube of liquid one centimeter on a side and is therefore one cubic centimeter (cc). That’s about the volume of your average grape.
One milliliter (one cc) of pure water weighs 1 gram and equals about 20 drops from the faucet. (A thousand grams is a kilogram, or 2.2 lbs.)
One teaspoon equates to about 5 milliliters. (So, in the example above, ¾ teaspoon would be 3.75 mL, which is easy to estimate on a graduated syringe.)
So, let’s each of us call on our Congress person to finally make metric measurement mandatory in the United States, for medicine at least, and to require that all liquid medicines be packaged with metric measuring devices (plastic syringes are cheap). That way we can at least claim to be more modern than the other two countries that don’t have it yet: Liberia and Burma. The only thing I can see standing in the way is if the Tea Party sees this as some kind of Kenyan plot. That could never happen. Could it?
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Still Skeptical After All These Years 
I still recall my sixth grade teacher (1965) saying that we were on our way to replacing our system of measurement with the metric system. We’ve come a long way! ,,, Your suggestion makes sense … and would be easy for that industry, which probably does all (or at least most) of its work in metrics. Then again, because it makes so much sense, no way Congress will buy into it. After all, the powerful Measurement Lobby would eventually make the call.
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Right, Frank. I only have to look at my tools to realize how profitable it is for manufacturers that we all need two versions for wrenches, hex wrenches, sockets, fittings, spark plugs, screws, etc. The industry is hooked.
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Sorry, not for me. No metric. Nyet. Yes, the Tamiflu packaging was incredibly and inexcusably confusing. Quite simply, the instructions on the package should have matched whatever was marked on the dropper, or vice versa. Had they been consistent, it wouldn’t have mattered which unit of measure was being employed.
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Unfortunately, the average consumer of medicine isn’t really concerned about measurement, so why should the industry be? From what I read, just getting the medicine has a placebo effect and many people forget doses altogether or fail to complete prescribed courses of antibiotics. Although not everyone’s like that, dosage errors are common, even in hospitals. Forbes Magazine reports:
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Jim, not only is it a Kenyan plot, it would cost money.
I did my part during my science teaching years to use the metric system for our work. I even replaced the 12 hour wall clock face with one that had 10 hours. I offered XC to anyone if they converted their age into the metric equivalent. I got no takers. If you can’t get kids to do something for XC, there is no way in h… that the country will switch.
Just sayin’…. 🙂
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It would, but only a little I think. A single oral syringe purchased on the internet runs several dollars, but I can get real syringes at my local pharmacy, complete with needles, for a dollar apiece. (I use them for vitamin B-12 shots.) Without the needles and bought in bulk, I’ll bet they’d be only a few cents apiece.
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Oh…I meant the switch to metric would cost some money. Some people refuse to spend money on the best of ideas.
The syringes are not the problem. I agree.
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🙂
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I can easily work in metric, but I just can’t visualize it. If someone says I’m 10 miles away from a location I can visualize it. 10 km? I’m like “Wait… is that close by or is that far? Could I walk there? Should I get a hotel room?”
I admit, though, we should just bite the bullet and do it. The Brits switched a few decades ago. They’re still around 😉
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Right, Jen. I think most everyone has that problem. Same with learning a new language. If you’re always translating in your head the process is slow and painful, but when you immerse, you begin to think in the other language. With SI and temperature, you shouldn’t convert C to F to understand tomorrow’s forecast but rather think, hmm, 20 degrees C, nice but a little on the cool side. It requires an effort, and therein lies the problem. 🙄
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I saw your comments on ShimonZ’s blog and found them interesting so I have come to take a look. As a mathematician I tend to agree wit you.When I was in hospital the nurse said 7 x25 =165 and was annoyed when I said she was wrong.. if they can’t so that then of course there will be errors.. but it’sawful if people die for such reasons.
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Based on both reading and my own observations I think deaths from dosage errors are rare, Katharine, but they cause much mischief in side effects when too strong and are ineffective when too weak. Medicine’s little secret is that most conditions get better with time, regardless of medication, and that insulates institutions and professionals from the effects of errors.
Thanks for visiting. 🙂
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I liked your writing about war and history.:)
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Aw, shucks. 🙂
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