SoylentNews

owl [soylentnews.org] writes:

Patients often come into clinics on a grocery list of medications. Common prescriptions include lisinopril 20 mg, amlodipine 2.5 mg, metformin 500 mg, and aspirin 81 mg. One dosage stands out from the others. While most medications come in dosages of round numbers or common decimals, low-dose aspirin has a standard dose of 81 mg.

Why is aspirin available at a dose of 81 milligrams? The answer is historical in nature and is rooted in a medieval and now defunct system of measurement called the apothecary system of weights and measures. The full explanation of aspirin 81 requires some background information on the apothecary system and is best explained in comparison to the more familiar metric system.

Original Submission