What is the dosage for quinapril?

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.

Which drugs or supplements interact with quinapril?

: 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.