Polypharmacy for Hypertension and Lipid Control: Why so Many Drugs?

Thursday, August 11, 2005

Breakout Session

Speaker
Curtis Triplitt, PharmD, CDE

Reported by Joelle Escoffery, PhD

Although the Framingham Heart Study demonstrated that incidence of cardiovascular disease has decreased over time, many patients with diabetes still fail to meet lipid and blood pressure targets. Current lipid goals suggest that LDL should be the first-line cholesterol goal. A goal of 100 mg/dL is recommended by the Adult Treatment Panel III (ATP III), with the option to decrease the goal to 70 mg/dL for very high risk patients with cardiovascular disease or cardiovascular disease risk equivalents. There are a variety of reasons to support the use of combination therapy to reach lipid targets. Combination therapy has the possibility of affecting LDL, HDL, and triglycerides and may affect other factors such as particle size, fibrinogen, and carotid intima media thickness.

Although clinical data support the use of statin monotherapy, there is far less outcome data for combination therapies. Available research on combination therapies has demonstrated that the addition of ezetimibe to a statin can lower LDL cholesterol with lower doses of statin than would be used in monotherapy. Combination therapy with niacin and statin treatment is an effective strategy to reduce persistently high HDL, whereas fibrate and statin therapy combination is effective to meet triglyceride targets. However, the statin and fibrate combination increases risk of myopathy and rhabdomyolysis. For patients who have an adverse reaction, fish oil may be substituted for fibrate therapy. Additionally, treatment with rosiglitazone or pioglitazone may also have effects on lipids and may be considered for combination therapy.

There are numerous classes of agents available for the treatment of hypertension, including angiotensin converting enzyme inhibitors (ACE inhibitors), angiotensis receptor blockers (ARBs), calcium channel blockers, β blockers, diuretics, and α blockers. On average, monotherapy will result in a 10 mm hg reduction in systolic blood pressure and a 5 mg hg reduction in systolic blood pressure, again suggesting that combination therapy will be needed in a majority of patients. Combination therapy choices can be made on the basis of a variety of factors, including efficacy, safety, side effects, contraindications, cost, and adherence. Effective combinations include: β blockers and diuretics, ACE inhibitors and diuretics, ACE inhibitors and calcium channel blockers, and ARBs and diuretics. Because losartan and diovan have the most clinical evidence supporting their efficacy, they tend to be more frequently used. Certain agents are less effective in certain groups. For example, β blockers and ACE inhibitor monotherapy may be less effective among African Americans. Although there are benefits to combination therapies, increasing the number of medications used may result in decreased medication adherence.