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.
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:
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?