Isotretinoin
Isotretinoin is a teratogen; there is about a 20–35% risk for congenital defects in infants exposed to the drug "in utero", and about 30–60% of children exposed to isotretinoin prenatally have been reported to show neurocognitive impairment. Because of this, there are strict controls on prescribing isotretinoin to women who may become pregnant and women who become pregnant while taking isotretinoin are strongly advised to terminate their pregnancies.
Buprenorphine
The waiver, which can be granted after the completion of an eight-hour course, is required for outpatient treatment of opioid addiction with Subutex and Suboxone. Initially, the number of patients each approved physician could treat was limited to ten. This was eventually modified to allow approved physicians to treat up to a hundred patients with buprenorphine for opioid addiction in an outpatient setting. This limit was recently increased by the Obama administration, raising the number of patients to which doctors can prescribe to 275. Still, due to this patient limit and the requisite eight-hour training course, many continuing patients can find it very difficult to get a prescription, despite the drug's effectiveness.