What does the abbreviation "q" signify when prescribing medication?

The abbreviation "q" is derived from the Latin word "quaque," meaning "every." In the context of prescribing medication, it denotes that a prescribed medication should be taken at defined intervals. For instance, if a prescription states "q12h," it indicates that the medication should be taken every 12 hours. This usage is crucial in ensuring that patients adhere to the prescribed dosage schedule to maintain effective therapeutic levels of the medication. This clear understanding of "q" helps prevent confusion in administration, thereby promoting patient safety and adherence to treatment plans.