|Lotensin (benazepril HCl)
Potential health benefits 2008
|FDA ALERT-SERIOUS SIDE EFFECTS [06/2006]: On June 8, 2006, the New
England Journal of Medicine published an article reporting that infants whose
mothers had taken an angiotensin-converting enzyme inhibitor (ACE inhibitors)
drug during the first trimester of pregnancy had an increased risk of major
congenital malformations, compared with infants who had not undergone first
trimester exposure to ACE inhibitor drugs. The number of cases of birth defects
is small and the findings of this study have not yet been repeated (see below for
more information about the study). According to the approved labels, ACE
inhibitor drugs are labeled as pregnancy category C for the first trimester of
pregnancy, though they are labeled pregnancy category D during the second
and third trimesters and the existing prescribing information recommends
discontinuing the ACEI as soon as possible if a patient becomes pregnant.
Because of the preliminary nature of the newly published data, the FDA does not
plan to change the pregnancy categories at this time, but healthcare
professionals should take these findings into consideration with other information
about a patient’s medical situation during early pregnancy.
|Benazepril HCl (summary of insert;
What is Benazepril HCl?
Benazepril hydrochloride is a white to off-white crystalline powder, soluble (>100
mg/mL) in water, in ethanol, and in methanol. Benazepril’s chemical name is 3-
1-(3S)-benzazepine-1-acetic acid monohydrochloride.
Benazeprilat, the active metabolite of benazepril, is a non-sulfhydryl
angiotensinconverting enzyme inhibitor. Benazepril is converted to benazeprilat
by hepatic cleavage of the ester group.
Strengths, Dosage Form of Lotensin
Lotensin is supplied as tablets containing 5 mg, 10 mg, 20 mg, and 40 mg of
benazepril hydrochloride for oral administration. The inactive ingredients are
colloidal silicon dioxide, crospovidone, hydrogenated castor oil (5-mg, 10-mg,
and 20-mg tablets), hypromellose, iron oxides, lactose, magnesium stearate (40-
mg tablets), microcrystalline cellulose, polysorbate 80, propylene glycol (5-mg
and 40-mg tablets), starch, talc, and titanium dioxide.
Pharmacology-Mechanism of Action
Benazepril and benazeprilat inhibit angiotensin-converting enzyme (ACE) in
human subjects and animals. ACE is a peptidyl dipeptidase that catalyzes the
conversion of angiotensin I to the vasoconstrictor substance, angiotensin II.
Angiotensin II also stimulates aldosterone secretion by the adrenal cortex.
Inhibition of ACE results in decreased plasma angiotensin II, which leads to
decreased vasopressor activity and to decreased aldosterone secretion. The
latter decrease may result in a small increase of serum potassium. Hypertensive
patients treated with Lotensin alone for up to 52 weeks had elevations of serum
potassium of up to 0.2 mEq/L. Similar patients treated with Lotensin and
hydrochlorothiazide for up to 24 weeks had no consistent changes in their serum
Removal of angiotensin II negative feedback on renin secretion leads to
increased plasma renin activity. In animal studies, benazepril had no inhibitory
effect on the vasopressor response to angiotensin II and did not interfere with
the hemodynamic effects of the autonomic neurotransmitters acetylcholine,
epinephrine, and norepinephrine. ACE is identical to kininase, an enzyme that
degrades bradykinin. Whether increased levels of bradykinin, a potent
vasodepressor peptide, play a role in the therapeutic effects of Lotensin remains
to be elucidated. While the mechanism through which benazepril lowers blood
pressure is believed to be primarily suppression of the renin-angiotensin-
aldosterone system, benazepril has an antihypertensive effect even in patients
with low-renin hypertension.
Pharmacokinetics Following oral administration of Lotensin, peak plasma
concentrations of benazepril are reached within 0.5-1.0 hours. The extent of
absorption is at least 37% as determined by urinary recovery and is not
significantly influenced by the presence of food in the GI tract.
Cleavage of the ester group (primarily in the liver) converts benazepril to its
active metabolite, benazeprilat. Peak plasma concentrations of benazeprilat are
reached 1-2 hours after drug intake in the fasting state and 2-4 hours after drug
intake in the nonfasting state. The serum protein binding of benazepril is about
96.7% and that of benazeprilat about 95.3%.
Benazepril is almost completely metabolized to benazeprilat, which has much
greater ACE inhibitory activity than benazepril, and to the glucuronide
conjugates of benazepril and benazeprilat. Only trace amounts of an
administered dose of Lotensin can be recovered in the urine as unchanged
benazepril, while about 20% of the dose is excreted as benazeprilat, 4% as
benazepril glucuronide, and 8% as benazeprilat glucuronide.
The kinetics of benazepril are approximately dose-proportional within the dosage
range of 10-80 mg. In adults, the effective half-life of accumulation of
benazeprilat following multiple dosing of benazepril hydrochloride is 10-11 hours.
Thus, steady-state concentrations of benazeprilat should be reached after 2 or
3 doses of benazepril hydrochloride given once daily.
Pharmacodynamics Single and multiple doses of 10 mg or more of Lotensin
cause inhibition of plasma ACE activity by at least 80%-90% for at least 24 hours
after dosing. Pressor responses to exogenous angiotensin I were inhibited by
60%-90% (up to 4 hours post-dose) at the 10-mg dose.
Administration of Lotensin to patients with mild-to-moderate hypertension results
in a reduction of both supine and standing blood pressure to about the same
extent with no compensatory tachycardia.
Indication Lotensin is indicated for the treatment of hypertension. It may be
used alone or in combination with thiazide diuretics.
Side Effects Lotensin has been evaluated for safety in over 6000 patients with
hypertension; over 700 of these patients were treated for at least one year. The
reported side effects were generally mild and transient, and there was no relation
between side effects and age, duration of therapy. The most common reasons
for discontinuation were headache (0.6%) and cough (0.5%). Common side
effects are headache, dizziness, fatigue, somnolence, postural dizziness, nausea
and cough. It may also lead to symptomatic hypotension, angioedema, Stevens-
Johnson syndrome, dermatitis, anxiety, pancreatitis, constipation, gastritis,
vomiting, and melena. Please, check with doctor for details.
Novartis Pharmaceuticals Corporation
A study that included more than 11,000 patients showed that pill that contains
two blood pressure drugs (benazepril and hydrochloro-thiazide) was more
effective than a diuretic-based strategy in reducing the risk of serious
cardiovascular problems and death in people with high blood pressure. [1A]
ALL RIGHTS RESERVED 2008
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Reference [1A] Battle against heart attack, stroke aided by science Gannett News Service
www.news-press.com December 9, 2008