What does the medical abbreviation prn mean?
PRN means "as needed." It stands for "pro re nata" which translates to "in the circumstances."It is routinely used by physicians in prescribing instructions to mean "as needed for." An example of such might include "Benadryl 50mg qhs prn insomnia."("qhs" is another Latin abbreviation, which stands for quaque hora somni, or "at the hour of sleep or bedtime.") Fortunately for patients, pharmacists are also familiar with these shorthand notations. Therefore, when used in medical situations, specifically for medications, it means that the medication is to be used only when needed, rather than on a consistent basis.