High activity antiretroviral therapy may exacerbate the activity of ergot alkaloids due to an inhibition of cytochrome P450. We report a 57 years old female with AIDS treated with lamivudine, zidovudine, atazanavir, ritonavir and cotrimoxazole presenting with ischemic signs in the four limbs. There was acrocyanosis and weak radial and ulnar pulses. A family member referred that the patient used ergot alkaloids for headaches. An ergotism due to the simultaneous use of ergot alkaloids and antiretroviral therapy was suspected. The latter was discontinued and intravenous nitroglycerin, nifedipine and pentoxifyline were started with good results.