Ergotamine is contraindicated with ritonavir as coadministration is likely to result in increased plasma concentrations of ergotamine leading to acute ergot toxicity, including vasospasm and ischaemia.

Ergotamine is contraindicated with ritonavir due to potential for serious and/or life threatening reactions such as acute ergot toxicity characterised by vasospasm and ischemia of the extremities and other tissues including the central nervous system.

A case was reported of a 34-year-old HIV positive man treated with saquinavir, ritonavir and abacavir/lamivudine who developed left foot pain with a diminished pulse one day after starting ergotamine for migraine. His symptoms resolved two days after withdrawing ergotamine. The authors hypothesise a drug-drug interaction occurred via inhibition of CYP3A4 by saquinavir and ritonavir.

A case study describes an HIV+ female who was stable on a regimen containing ritonavir (600 mg every 12 hours), lamivudine (150 mg every 12 hours) and stavudine (40 mg every 12 hours). She developed signs of severe vascular involvement and irreversible coma after the reported administration of ergotamine tartrate (3 x 1 mg over the 4 day preceding the onset of signs and symptoms). There was no change in the patient’s neurological state (coma vigil) 2 years after the diagnosis was made.

There are various case reports of persons developing severe ergotism after taking ergotamine whilst on ritonavir. Any administration of ergot alkaloids should be discontinued when ritonavir treatment is started.