Abstract
Background: Off-label medication use (OLMU) refers to the intentional use of authorized products for unapproved clinical indications, unapproved dosing frequencies or durations, unapproved routes of administration, or unapproved age groups. Different reasons exist for prescribing off-label medication, including the high cost of approving a new indication and the exclusion of specific populations, such as children, from clinical trials. This study evaluated the extent and patterns of OLMU practices at King Saud University Medical City.
Methods: This was a retrospective analysis of completed Form B (Physicians filled form) submissions from January 2017 to December 2020. Patient demographic data, OLMU data (drug, dose, and duration of treatment), and the department of the prescriber were collected from each Form B. Categorical variables were determined as frequency and percentage using Microsoft Excel® 2016; numerical variables were also calculated as mean and median.
Results: Out of 830 reviewed forms, 95.06% (n = 789) were approved, and 4.94% (n = 41) were rejected. More than half of the forms, 50.48% (n = 419), were for antineoplastic and immunomodulating agents (mainly bevacizumab). Prescription of off-label medication was primarily due to the failure of previous medications or therapies at 20.84% (n = 176), followed by the need for aggressive treatment at 19.64% (n = 163). The most common pattern of OLMU was an unapproved indication at 33.13% (n = 275), followed by an unapproved route of administration at 31.33% (n = 260). Out of the 41 rejected forms, 86.29% (n = 28) were rejected due to stock unavailability.
Conclusion: Our findings recommend further studies to assess the evidence supporting OLMU, as well as its safety and efficacy.

Key words: Off-label medication use, Saudi Arabia, unapproved indication, unapproved route of administration.