CYP2C9 and hypothyroidism: Factors such as age over 80 years, untreated hypothyroidism, low serum vitamin D levels, hypertension, high statin doses, and concomitant use of medications affecting cytochrome P450 systems (CYP3A4, CYP2C9) and the OATP1B1 protein have been associated with an increased incidence of this adverse effect of statins [1].