Are there medicines I should avoid if I am taking PCSK9-inhibitors to lower my cholesterol?

There are no reported drug-drug interactions with PCSK9-inhibitors.¹ They are not metabolized or cleared by the liver or kidneys and therefore there is no need to adjust the dose in patients with either liver or kidney disease. No drug-drug interactions were listed on package inserts for alirocumab or evolocumab.^2,3 However, PCKS9-inhibitors are biologics and some biologics that have been prescribed for inflammatory diseases have caused an increased risk of infections when combined with other biologics. For this reason, caution should be exercised before PCSK9-inhibitors are co-prescribed with other biologics.⁴

Bellosta et al. reviewed what is known about other lipid-lowering drugs’ interaction with PCSK9-inhibitors.⁵ The coadministration of statins with alirocumab or evolocumab results in an increase in the clearance of the PCSK9-inhibitors. Compared to monotherapy, combination therapy results in a 40%, 15%, and 35% lower exposure to alirocumab when it is given with statins, ezetimibe, and fenofibrate, respectively. However, this drug-drug interaction is not a contraindication to combination therapy and its therapeutic goal of low-density lipoprotein cholesterol reduction is maintained when the drugs are co-administered.

^References

1. Feingold KR, Grunfeld C. Cholesterol Lowering Drugs. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext [Internet]. South Dartmouth (MA): MDText.Com, Inc.; 2000-. 2018 Dec 13. South Dartmouth (MA); 2018.
2. Evolocumab [package insert]. Thousand Oaks, CA: Amgen; 2017.
3. Alirocumab [package insert]. Bridgewater, NJ: Sanofi-aventis US, LLC; 2017.
4. Humira [package insert]. North Chicago, IL: AbbVie, Inc; 2019.
5. Bellosta S, Corsini A. Statin drug interactions and related adverse reactions: an update. Expert Opin Drug Saf 2018; 17 (1): 25-37.