quinapril (Accupril)

Quinapril belongs in a class of drugs called angiotensin converting enzyme (ACE) inhibitors. ACE inhibitors are used for treating high blood pressure and heart failure and for preventing kidney failure due to high blood pressure and diabetes.

Other drugs in this class are enalapril (Vasotec), ramipril (Altace), captopril (Capoten), fosinopril (Monopril), benazepril (Lotensin), lisinopril (Zestril, Prinivil), moexipril (Univasc) and trandolapril (Mavik). ACE is important because it produces angiotensin II. Angiotensin II contracts the muscles of the arteries in the heart and the rest of the body, narrowing the arteries and thereby elevating blood pressure. In the kidney, the narrowing caused by angiotensin II decreases blood flow and increases the arterial filtration pressure in the kidney. ACE inhibitors such as quinapril lower blood pressure by inhibiting the formation of angiotensin II, thereby relaxing the arterial muscles and enlarging the arteries. This increases the flow of blood and oxygen to the heart so that it can pump blood more efficiently.

The enlargement of the arteries elsewhere in the body also makes it easier for the heart to pump blood. This is particularly beneficial when there is heart failure. In the kidneys ACE inhibitors increase blood flow and reduce the filtration pressure in the kidneys.

Quinapril was approved by the FDA in November 1991.

What brand names are available for quinapril?

Accupril

Is quinapril available as a generic drug?

Yes

Do I need a prescription for quinapril?

Yes

Quinapril is generally well tolerated, and side effects are usually mild and transient. A dry, persistent cough has been reported with the use of quinapril and other ACE inhibitors. Coughing resolves after discontinuing the medication.

Other side effects include:

• abdominal pain,
• constipation,
• diarrhea,
• rash,
• dizziness,
• fatigue,
• headache,
• loss of taste,
• loss of appetite,
• nausea, vomiting,
• fainting, and
• numbness or tingling in the hands or feet.

Quinapril and other ACE inhibitors may also cause kidney failure and increased levels of potassium in the blood. The most serious but very rare side effects are liver failure and angioedema (swelling of lips and throat).

The recommended dose for treating high blood pressure is 10-80 mg a day as a single dose or in two doses every 12 hours. Start at 5 to 20 mg daily. The initial dose for heart failure is 5 mg every 12 hours and the maintenance dose is 20 to 40 mg a day as a single dose or in two divided doses every 12 hours. Quinapril should be taken on an empty stomach because food reduces its absorption.

: The use of ACE inhibitors with potassium supplements, salt substitutes or diuretics (for example, spironolactone [Aldactone]) that increase potassium in the blood may lead to excessive potassium levels in the body. Potassium levels should be closely monitored whenever ace inhibitors are use in combination with these drugs.

Patients receiving diuretics or are dehydrated or have low blood sodium may experience excessive reduction in blood pressure when quinapril is started. Stopping the diuretic or increasing salt intake prior to taking quinapril may prevent this excessive reduction in blood pressure. 

There have been reports that aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs) such as ibuprofen (Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc.), indomethacin (Indocin, Indocin-SR), and naproxen (Anaprox, Naprelan, Naprosyn, Aleve) may reduce the effects of ACE inhibitors.

Combining quinapril or other ACE inhibitors with non-steroidal anti-inflammatory drugs (NSAIDs) in patients who are elderly, volume-depleted (including those on diuretic therapy), or with poor kidney function may result in reduced kidney function, including kidney failure. These effects usually are reversible.

There have been reports of increased lithium (Eskalith, Lithobid) levels when lithium is used in combination with ACE inhibitors. The reason for this interaction is not known.

Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) may occur when injectable gold (sodium aurothiomalate), used in the treatment of rheumatoid arthritis, is combined with ACE inhibitors, including quinapril.

Quinapril should not be combined with aliskiren (Tekturna) because the combination of both drugs increases blockade of angiotensin leading to low blood pressure, increased blood potassium, and possible kidney damage.

Angiotensin converting enzyme inhibitors, including quinapril, are very harmful to the fetus and, therefore, should not be used during pregnancy.

Quinapril is secreted into breast milk. Because of the risk of harm to the infant, quinapril should be used with caution during breastfeeding.

What preparations of quinapril are available?

Tablets: 5, 10, 20 and 40 mg

How should I keep quinapril stored?

Tablets and solutions should be stored at room temperature 15 C to 30 C (59 F to 86 F).