A prescription stating 1 tab QID prn pain means the patient should take one tablet:

The prescription indicating "1 tab QID prn pain" instructs the patient to take one tablet four times a day as needed for pain. The abbreviation "QID" stands for "quater in die," which translates to "four times a day." The "prn" part means "as needed," indicating that the patient should take the medication only when experiencing pain, rather than on a fixed schedule regardless of pain levels.

This usage of both terms helps clarify when and how often the tablet should be taken: the patient can decide to take the medication up to four times a day based on their immediate needs for pain relief. This is crucial for managing any discomfort the patient may experience while avoiding unnecessary medication intake when pain is minimal or absent.