Which abbreviation indicates that medication should be taken four times a day?

The abbreviation that indicates medication should be taken four times a day is "q.i.d.," which stands for "quater in die," a Latin phrase meaning "four times a day." This term is commonly used in medical prescriptions to instruct patients on how frequently to take their medication throughout the day. By following this abbreviation, patients can effectively manage their medication schedule, ensuring they receive the appropriate dosage as directed by their healthcare provider.

Other abbreviations do not denote four times a day. For example, "b.i.d." stands for "bis in die," meaning twice a day, and "t.i.d." stands for "ter in die," meaning three times a day. The abbreviation "a.c." refers to taking medication before meals, which does not indicate the frequency of doses in a day. Understanding these abbreviations is essential for proper medication management and adherence to prescribed treatment plans.