The OAF is to be collected within 4 weeks of enrollment and is required
every 3 months following vigabatrin initiation (with a 3-month
grace period). Additionally, an OAF is required 3–6 months after patients
discontinue vigabatrin treatment. For active patients, if an OAF
is not received by 90 days after the testing due date, the prescriber is notified
that the next month's Sabril® prescription will not be renewed,
and the prescriber must fax a final prescription to allow for tapering
off of vigabatrin.