Amlodipine Besylate/Benazepril Hydrochloride

The use of fixed-dose combinations (FDCs) has been increasing since the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommended using ≥2 drugs as the first-line drug therapy for patients with stage 2 hypertension. FDCs simplify the drug therapy regimen and reportedly lower the drug therapy cost compared with the free combination (FC) of 2 single-agent drugs. This study hypothesized that the affordability of FDCs over FCs would change over time depending on the availability of generic single-agent drugs.

This study used the 2009 Medical Expenditure Panel Survey. Antihypertensive drugs were identified based on the Food and Drug Administration national drug directory. Based on the 2 databases, regression models were run to predict average monthly drug cost as well as out-of-pocket cost for each prescription along with their 95% confidence intervals (CIs).

Overall, FDCs (n = 26) had average monthly drug costs similar to respective FCs when FCs were not generically available. However, when FCs were generically available, FDCs (n = 11) had average drugs costs much higher than their respective FCs. For example, Lotrel as an FDC had an average monthly drug cost of $115.97 (95% CI = $96.59-$135.36), whereas its counterpart FC had an average monthly drug cost of $21.00 (95% CI = $18.23-$23.79).

The cost advantage of FDCs over FCs was reversed when FCs were generically available. The finding of this study informs patients, health-care providers, and drug plans of the importance of making dynamic decisions on preferred drug therapy options depending on the availability of generic drugs.

Cardiovascular (CV) disease, its associated risk factors and continued progression run in parallel with renal deterioration (cardio-renal syndrome). Most guidelines promote early treatment, including the use of ACE inhibitors to control CV risk in patients with chronic renal failure. The renoprotective effects of the ACE inhibitor, benazepril, independent of blood pressure control, have been demonstrated, as monotherapy or in combination with amlodipine or hydrochlorothiazide, in large clinical trials: Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH) and Gauging Albuminuria Reduction with Lotrel in Diabetic Patients with Hypertension (GUARD) in patients with mild-to-severe chronic kidney disease. In the ACCOMPLISH trial, CV outcomes and renoprotective effects were greater in patients receiving benazepril in combination with amlodipine; the GUARD trial demonstrated that combined benazepril/hydrochlorothiazide was more effective than amlodipine combined with benazepril in reducing baseline urinary albumin:creatinine ratio and normalizing urinary albumin:creatinine ratio in patients with baseline microalbuminuria, although this effect was accompanied with a greater decrease in glomerular filtration rate than with benazepril/amlodipine. While this is not a study in patients with overt renal disease (patients had severe CV diseases), the ACCOMPLISH trial is the first large study to date to show the added benefit of combining ACE inhibitors and calcium-channel blockers in renal protection. Future large, well-controlled trials, designed to evaluate hard renal outcomes, are required to identify which patients will benefit most from particular combination treatment strategies in renoprotection.