BENAZEPRIL

(for veterinary information only)

BRAND NAME: LOTENSIN, FORTEKOR, CARDALIS (combined with spironolactone)

AVAILABLE IN
5 mg, 10 mg,
20 mg and 40 mg
TABLETS

HEART FAILURE MANAGEMENT

Benazepril is used in two situations: heart failure management and renal (kidney) protein loss. It may seem strange that one medication could have important effects on two separate organ systems like this but, in fact, the heart and kidney have a special relationship when it comes to blood pressure and circulation and this is where benazapril fits in. Benazepril is an Angiotensin Converting Enzyme Inhibitor, more commonly known as an "ACE Inhibitor" or simply as an "ACEI." It works to dilate blood vessels in the body. When blood vessels dilate (get bigger), the blood pressure within will drop. This is good if one wants to lower abnormally high blood pressure but it turns out other medications may be more effective for that purpose. The real benefit to dropping pressure in those blood vessels is that the heart does not have to work as hard when pumping against lower pressure there. Less work is important when the heart is weak and cannot handle.

RENAL (KIDNEY) PROTEIN LOSS

The kidney's main job is to sort out which blood chemicals need to be dumped and which one's need to be kept. One thing for sure is that protein should always be kept. Protein is a very important resource and it is not easy to make. To be sure protein is kept in the body and not lost in urine with the waste chemicals being dumped, there are special filtration membranes keeping protein in. The problem is that certain diseases damage these membranes and protein is urinated away. Losing too much protein or just too much of an important protein can be disastrous. Fortunately, ACE Inhibitors help with this by lowering blood pressure within the kidney's filtration units. The result is less protein loss in urine.

HOW THIS MEDICATION IS USED

Benazepril is used in the treatment of congestive heart failure and in the treatment of renal (kidney) protein-loss (such as glomerulonephritis). Benazepril is removed from the body via both the liver and the kidneys and, in patients with poor kidney function, it is frequently chosen over enalapril, another ACEI that is removed via the kidneys only. In other words, using benazapril instead allows the liver to take over some of the work from the kidney when it comes to removing the drug.

In heart failure patients, when benazepril is commonly given in conjunction with a diuretic
(like furosemide or spironolactone), kidney parameters (BUN and Creatinine)
should be measured prior to benazepril use, again 3-7 days
after benazepril therapy has started, and periodically thereafter.
Kidney function should also be rechecked after any dose change in the heart failure patient.

Benazepril may be given with or without food and is usually given once a day. If a dose is accidentally skipped, do not double up on the next dose; simply pick up with the next dose when it is remembered.

SIDE EFFECTS

In some patients, blood pressure can drop too low as the peripheral blood vessels are dilated. This manifests as listlessness and lethargy. Often the dose of benazepril can be modified should this side effect occur.

Benazepril may lead to elevations in potassium blood levels.

INTERACTIONS WITH OTHER DRUGS

Benazepril is commonly used in combination with diuretics, especially furosemide. In this situation, monitoring kidney parameters is especially important as both these medications serve to decrease blood supply to the kidney as they support the heart. Should a heart failure crisis occur while a patient is on these two medications, it will become necessary to rely on the diuretic to resolve the crisis. High doses of diuretic are typically needed. This can potentially lead to kidney failure though there is no alternative when the heart is failing.

Blood potassium levels can become dangerously high when benazepril is used with other medications that elevate blood potassium level. Such drugs might include: potassium supplements (Polycitra, or Urocit-K) or spironolactone (a potassium sparing diuretic.)

Benazepril is less effective in the presence of aspirin or other NSAIDs. Concurrent use of benazepril and NSAIDs can increase the potential for kidney toxicity.

Benazepril may increase the risk of hypoglycemia (low blood sugar) when used concurrently with insulin or with oral hypoglycemic agents.

Medications that can compound the potential for dropping blood pressure when combined with benazepril include: dexmedetomidine (used for anxiety), antihistamines including phenothiazine tranquilizers like acepromazine, angiotensin receptor antagonists, trazodone, benzodiazepine tranquilizers, mirtazapine (an appetite stimulant), pentoxifylline, muscle relaxers, and opioids.

CONCERNS AND CAUTIONS

Benazepril is inactive when it is consumed and must be activated into “benazeprilat” (its active form) by the liver. If the patient’s liver is in failure and cannot reliably perform this conversion, an ACE inhibitor that does not require conversion can be used.

Benazepril probably should not be used in patients with impaired kidney function.

This medication should not be used in pregnancy or lactation.

Short version (to help us
comply with "Lizzie's Law")

Page originally posted: 10/19/07
Page last updated: 3/2/2022