Engelsk titel: Interaction risk with statin switch
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Författare:
Molden E
;
Westergren T
Email: tone.westergren@rikshospitalet.no
Språk: Nor
Antal referenser: 35
Dokumenttyp:
Översikt
UI-nummer: 07021914
Sammanfattning
INTERPRETATION : Interaction studies show that atorvastatin and simvastatin display differences in interaction potential toward warfarin and drugs inhibiting CYP3A4 metabolism. It is important to consider the risk of interactions when switching to or starting simvastatin treatment.
RESULTS : One interaction study was found for the warfarin-atorvastatin combination, but this showed no relevant changes in prothrombin time. Three interaction studies were identified for the combination warfarin-simvastatin and these showed consistently increased INR and/or reduced dose requirements for warfarin (10-30%) after starting treatment with simvastatin. Three studies had investigated the degree to which simvastatin and atorvastatin interact with a CYP3A4 inhibitor in the same population. In these studies, plasma concentrations of both statins increased, but the increases were several times greater for simvastatin than for atorvastatin.
MATERIAL AND METHODS : Relevant interaction studies were identified through searches in the databases PubMed and ISI Web of Knowledge. Interaction databases referring to primary sources and product monographs were also examined.
BACKGROUND : The article is based upon two adverse drug reaction reports after switch from atorvastatin to simvastatin. Simvastatin interactions with warfarin and the cytochrome P450-3A4 inhibitor diltiazem were suspected as possible causes of the events (fatal intracranial haemorrhage with INR > 8 and myopathy). Relevant literature was examined to evaluate potential differences in atorvastatin and simvastatin interaction profiles.