Accupril (quinapril) is an angiotensin-converting-enzyme (ACE) inhibitor, marketed by Pfizer, that is used to treat high blood pressure and heart failure.

ACE inhibitors are used to slow the progression of kidney disease and to increase life expectancy in Alport syndrome patients. They also have been shown to reduce proteinuria (protein in the urine), which is associated with kidney damage.

How Accupril works

ACE inhibitors like Accupril inhibit the angiotensin-converting-enzyme that converts a hormone called angiotensin 1 into another hormone called angiotensin 2. Angiotensin 2 increases blood pressure by narrowing blood vessels and increasing blood volume through the retention of sodium and chloride.

By blocking ACE, ACE inhibitors, therefore, lower blood pressure. Besides this effect, ACE inhibitors have additional kidney-protecting properties that may explain the decrease in the level of protein in the urine. ACE inhibitors also reduce the glomerular filtration pressure and the permeability of the glomeruli, the small blood vessels in the kidney that filter waste products from the blood.

Accupril in clinical trials

Accupril has not been tested in randomized clinical trials specifically for Alport syndrome. However, one trial assessed the effect of Accupril and 15 other blood-pressure-lowering medications on blood pressure and the incidence of chronic kidney disease and other diseases. More specifically, the researchers investigated whether the time at which the medicine was taken (in the morning upon awakening or at bedtime) influenced the outcome.

A Phase 4 multicenter clinical trial (NCT00741585) at 40 participating clinical sites in Spain included  21,983 enrolled participants, of which 15,674 had been diagnosed with hypertension. Physicians could decide which medication to prescribe, but the participants were randomized to take the medication either upon awakening or at bedtime. Blood pressure was measured periodically for 48 hours. The follow-up time was about 10 years. The trial is completed, but results have not been published yet.

Additional information

Accupril promotes the retention of potassium. Potassium-rich foods, such as dairy products, salt substitutes, nuts, and certain fruits and vegetables should be avoided while taking this medication.

Common side effects of Accupril include headaches, coughing, tiredness, and dizziness.

