The ability of grapefruit juice to increase serum concentrations of drugs was first discovered during a study of the effect of ethanol on felodipine (Plendil) pharmacokinetics. Double-strength grapefruit juice used to disguise the taste of ethanol resulted in higher than expected serum concentrations of felodipine (DG Bailey et al, Clin Invest Med 1989; 12:357).

View Table 3: Some Drug Interactions with DAAs for HCV Infection

View the Expanded Table: Statins

Advertisements for atorvastatin (Lipitor), the market leader facing generic competition, have been in the news recently in the US. Lovastatin, pravastatin and simvastatin are all available generically at a much lower retail price or lower co-pay than atorvastatin.

The FDA has approved the marketing of a second fixed-dose combination of extended-release niacin (Niaspan) with a generic statin. Niaspan/simvastatin (Simcor - Abbott) is approved for use in patients with hypercholesterolemia or mixed dyslipidemia (high LDL-cholesterol, low HDL-cholesterol and high serum triglycerides). Niaspan/lovastatin (Advicor) was marketed previously for the same indications.

The FDA has announced changes in the labeling of simvastatin to reduce the risk of myopathy. These changes include limiting the use of the 80-mg maximum dose to patients who have been taking it for 12 months or more without evidence of myopathy and new recommendations for use of simvastatin with other drugs. Simvastatin is available alone (Zocor, and others) and in combination with ezetimibe (Vytorin) and with niacin (Simcor).

Fluvastatin (Lescol - Sandoz), an HMG-CoA reductase inhibitor, was recently marketed in the USA for treatment of hypercholesterolemia. A synthetic mevalonolactone derivative, it is chemically distinct from previously available drugs in this class.

Colesevelam hydrochloride (Welchol - Sankyo Pharma), a nonabsorbed hydrophilic polymer that binds bile acids, has been approved by the FDA for reduction of plasma LDL cholesterol in patients with primary hypercholesterolemia.

The FDA has approved mipomersen (Kynamro – Genzyme) and lomitapide (Juxtapid – Aegerion), each in addition to a low-fat diet and other lipid-lowering medications, to reduce cholesterol levels in patients with homozygous familial hypercholesterolemia (HoFH).

Citing some recent reports, the FDA has announced changes in the safety labeling of all HMG-CoA reductase inhibitors (statins).