Erythromycin Almotriptan

ALMOTRIPTAN, ELETRIPTAN MACROLIDES -CLARITHROMYCIN, ERYTHROMYCIN, TELITHROMYCIN t plasma concentrations of almotriptan and eletriptan, with risk of toxic effects, e.g. flushing, sensations of tingling, heat, heaviness, pressure or tightness of any part of body including the throat and chest, dizziness Almotriptan is metabolized mainly by CYP3A4 isoenzymes. Most CYP isoenzymes are inhibited by clarithromycin to varying degrees, and since there is an alternative pathway of metabolism by MAO-A, toxicity responses will vary between individuals Avoid co-administration... 

Clinically important, potentially hazardous interactions with almotriptan, amprenavir, clarithromycin, darunavir, delavirdine, efavirenz, erythromycin, fosamprenavir, indinavir, naratriptan, nelfinavir, nilotinib, ritonavir, rizatriptan, saquinavir, sibutramine, sumatriptan, telithromycin, tipranavir, troleandomycin, zolmitriptan... 

Erythromycin markedly raises the plasma levels of eletriptan. Clarithromycin, josamycin and troleandomycin are predicted to interact similarly. Almotriptan levels may be raised by erythromycin. Clarithromycin does not significantly alter the pharmacokinetics of sumatriptan. 

Other triptans would be expected to have little or no interaction with the azoles as they are not predominantly metaholised by CYP3A4 (see Table 16.2 , (p.597)). The exception to this is almotriptan, which is metabolised in part by CYP3A4. The US manufacturers therefore predict that its levels may be raised by erythromycin. However, note that, based on its interaction with ketoconazole , (p.601), dosage adjustments would not be expected to be necessary. 

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