Frank Szmulowicz, Ph. D. Jul 17, 2014:

Dose vs. dosage

Despite repeated emphasis upon the distinction between dose and dosage, these two terms continue to baffle us. As we’ve often been told, dose refers to a specified amount of medication taken at one time. In the preferred use of dosage, however, the term refers to the administering of a specific amount, number, and frequency of doses over a specified period of time. Dosage implies duration: a “dosage regimen” is a treatment plan for administering a drug over a period of time. One way to absolutely never forget the distinction between dose and dosage is to focus on the meaning of the suffix –age in dosage. Dose will then be understood by default.
http://www.medlinguistics.com/didyouknow.asp

literary (asker) Jul 17, 2014:

bo nie "rate"; "rate" to dawka jakiegoś nawozu