Ritonavir, and possibly indinavir, are predicted to reduce the
metabolism of
buspirone. A single case report describes Parkinson-like
symptoms attributed to concurrent use of
buspirone with
ritonavir and also possibly indinavir.
This appears to be an isolated case. However, the UK manufacturer of
buspirone recommends that a lower dose of buspirone, 2.5 mg twice daily, should be used with potent inhibitors of CYP3A4, such as
ritonavir.