Ergotamine Clarithromycin

Horowitz RS, Hart RC, Gomez IF. Clinical ergotism with lingual ischemia induced by clarithromycin-ergotamine interaction. Arch Intern Med 1996 156 456 -58. 

Pregnancy (ergotamine s powerful uterine stimulant actions may cause fetal harm) hypersensitivity to ergot alkaloids peripheral vascular disease (eg, thromboangiitis obliterans, leutic arteritis, severe arteriosclerosis, thrombophlebitis, Raynaud s disease) hepatic or renal impairment severe pruritus coronary artery disease hypertension sepsis. The use of potent CYP3A4 inhibitors (ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is contraindicated. 

Deravirdine (Rescnptor) [Antiretroviral/NNRTI] Uses HIV Infxn Action Nonnucleoside RT inhibitor Dose 400 mg PO tid Caution [C, ] CDC recommends HIV-infected mothers not to breast-feed (transmission risk) w/ renal/hepatic impair Contra Use w/ drugs dependent on CYP3A for clearance (Table VI-8) Disp Tabs SE Fat redistribution, immune reconstitution synd, HA, fatigue, rash, T transaminases, N/V/D Interactions T Effects W/ fluoxetine T effects OF benzodiazepines, cisapride, clarithromycin, dapsone, ergotamine, indinavir, lovastatin, midazolam, nifedipine, quinidine, ritonavir, simvastatin, terfena-dine, triazolam, warfarin effects W/ antacids, barbiturates, carbamazepine, cimetidine, famotidine, lansoprazole, nizatidine, phenobarbital, phenytoin, ranitidine, rifabutin, rifampin effects OF didanosine EMS Use of benzodiazepines and CCBs should be avoided may cause a widespread rash located on upper body and arms OD May cause an extension of nl SEs symptomatic and supportive Deferasirox (Exjade) [Iron Chelator] Uses Chronic iron overload d/t transfusion in pts >2 y Action Oral iron chelator Dose Initial 20 mg/kg... 

In patients with ergotamine toxicity, vasoconstriction can lead to frank ischemia. Clarithromycin interferes with ergotamine metabolism. 

A 41-year-old woman developed worsening lower leg pain, pallor, and a sensation of coolness aggravated by exertion there was severe vasospasm in the legs (61). She had taken a caffeine + ergotamine formulation for migraine for many years and had recently been given clarithromycin 500 mg bd for flu-hke symptoms. 

Clarithromycin has been reported to potentiate the effects of ergotamine. 

A 41-year-old woman presented with pain and pallor in the leg and a sensation of coolness exacerbated by exercise (34). For many years she had been taking a formulation containing ergotamine 1 mg plus caffeine 100 mg, at a dose of one or two tablets daily, for both prophylaxis and treatment of migraine. For 7 days she had also taken clarithromycin (dose is not stated) for a chest infection. Her legs were cool and cyanosed, with no palpable popliteal or foot pulses and an ankle-brachial index of only 0.6 (normal >0.8). 

Clinically important, potentially hazardous interactions with amiodarone, astemizole, bepridil, carbamazepine, chloroquine, cisapride, clarithromycin, dihydroergotamine, disopyramide, ergotamine, grapefruit juice, halofantrine, haloperidol, itraconazole, ketoconazole, methadone, moxifloxacin, phenobarbital, phenytoin, pimozide, procainamide, quinidine, rifampicin, ritonavir, sotalol, St John s wort, telithromycin, terfenadine, voriconazole... 

Ausband SC, Goodman PE An unusual case of clarithromycin associated ergotism. J Emerg Med 2001 21(4) 411-413. [PMID 11728770] (Lower-extremity vasospasm due to addition of clarithromycin in a patient with longstanding use of a caffeine-ergotamine preparation for migraine.)... 

Ergot toxicity can deveiop rapidiy in patients taking ergotamine or dihydroergotamine if they are given erythromycin or trolean-domycin. Three possibie cases of toxicity have occurred with clarithromycin, and one case has been reported with each of josamycin and oieandomycin. Toxicity is predicted to occur with midecamycin. No cases of toxicity appear to have been described with spiramycin, and none wouid be expected. There is no direct information about azithromycin but it would not be expected to interact. 

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