Ramipril

Ramipril capsules are an angiotensin converting enzyme (ACE) inhibitor indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. It may be used alone or in combination with thiazide diuretics (1.1) . In patients 55 years or older at high risk of developing a major cardiovascular event, ramipril capsules are indicated to reduce the risk of myocardial infarction, stroke, or death from cardiovascular causes ( 1.2 ). Ramipril capsules are indicated in stable patients who have demonstrated clinical signs of congestive heart failure post-myocardial infarction (1.3) .

1.1 Hypertension Ramipril capsules are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including this drug. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Ramipril capsules may be used alone or in combination with thiazide diuretics.

1.2 Reduction in the Risk of Myocardial Infarction, Stroke, and Death from Cardiovascular Causes Ramipril capsules are indicated in patients 55 years or older at high risk of developing a major cardiovascular event because of a history of coronary artery disease, stroke, peripheral vascular disease, or diabetes that is accompanied by at least one other cardiovascular risk factor (hypertension, elevated total cholesterol levels, low HDL levels, cigarette smoking, or documented microalbuminuria), to reduce the risk of myocardial infarction, stroke, or death from cardiovascular causes. Ramipril capsules can be used in addition to other needed treatment (such as antihypertensive, antiplatelet, or lipid-lowering therapy) [see Clinical Studies ( 14.2 )].

1.3 Heart Failure Post-Myocardial Infarction Ramipril capsules are indicated in stable patients who have demonstrated clinical signs of congestive heart failure within the first few days after sustaining acute myocardial infarction. Administration of ramipril capsules to such patients have been shown to decrease the risk of death (principally cardiovascular death) and to decrease the risks of failure-related hospitalization and progression to severe/resistant heart failure [see Clinical Studies (14.3) ] .

Ramipril is supplied as hard gelatin capsules containing 1.25 mg, 2.5 mg, 5 mg, and 10 mg of ramipril. Ramipril Capsules USP, 1.25 mg are yellow/yellow size ‘4’ hard gelatin capsules imprinted with ‘D’ on yellow cap and ‘05’ on yellow body with black edible ink filled with white to almost white powder. Ramipril Capsules USP, 2.5 mg are orange/orange size ‘4’ hard gelatin capsules imprinted with ‘D’ on orange cap and ‘06’ on orange body with black edible ink filled with white to almost white powder. Ramipril Capsules USP, 5 mg are red/red size ‘4’ hard gelatin capsules imprinted with ‘D’ on red cap and ‘07’ on red body with black edible ink filled with white to almost white powder. Ramipril Capsules USP, 10 mg are blue/blue size ‘4’ hard gelatin capsules imprinted with ‘D’ on blue cap and ‘08’ on blue body with black edible ink filled with white to almost white powder. Capsule: 1.25 mg, 2.5 mg, 5 mg, and 10 mg (3)

Ramipril capsules are contraindicated in patients who are hypersensitive to this product or any other ACE inhibitor (e.g., a patient who has experienced angioedema during therapy with any other ACE inhibitor). Ramipril capsules are contraindicated in combination with a neprilysin inhibitor (e.g., sacubitril). Do not administer ramipril capsules within 36 hours of switching to or from sacubitril/valsartan, a neprilysin inhibitor [see Warnings and Precautions (5.1) ] . Do not co-administer ramipril capsules with aliskiren:

• in patients with diabetes Angioedema related to previous treatment with an ACE inhibitor, or a history of hereditary or idiopathic angioedema (4) . Ramipril capsules are contraindicated in combination with a neprilysin inhibitor (e.g., sacubitril). Do not administer ramipril capsules within 36 hours of switching to or from sacubitril/valsartan, a neprilysin inhibitor ( 4 ). Do not co-administer aliskiren with ramipril capsules in patients with diabetes (4) .

Angioedema, increased risk in patients with a prior history (5.1) Hypotension and hyperkalemia (5.5, 5.8) Renal impairment: monitor renal function during therapy (5.3) Avoid concomitant use of an ACE inhibitor and angiotensin blocker (5.7) Rare cholestatic jaundice and hepatic failure (5.2) Rare neutropenia and agranulocytosis (5.4)

5.1 Anaphylactoid and Possibly Related Reactions Presumably because drugs that act directly on the renin-angiotensin-aldosterone system (e.g., ACE inhibitors) affect the metabolism of eicosanoids and polypeptides, including endogenous bradykinin, patients receiving these drugs (including ramipril) may be subject to a variety of adverse reactions, some of them serious. Angioedema Angioedema may occur at any time during treatment with ACE inhibitors including ramipril. Head and Neck Angioedema Patients with a history of angioedema unrelated to ACE inhibitor therapy may be at increased risk of angioedema while receiving an ACE inhibitor. A+ngioedema of the face, extremities, lips, tongue, glottis, and larynx has been reported in patients treated with ACE inhibitors. Angioedema associated with laryngeal edema can be fatal. If laryngeal stridor or angioedema of the face, tongue, or glottis occurs, discontinue treatment with ramipril and institute appropriate therapy immediately. Where there is involvement of the tongue, glottis, or larynx likely to cause airway obstruction, administer appropriate therapy (e.g., subcutaneous epinephrine solution 1:1000 [0.3 mL to 0.5 mL]) promptly [see Adverse Reactions (6) ] . In considering the use of ramipril, note that in controlled clinical trials ACE inhibitors cause a higher rate of angioedema in Black patients than in non-Black patients. In a large U.S. post-marketing study, angioedema (defined as reports of angio, face, larynx, tongue, or throat edema) was reported in 3/1523 (0.2%) Black patients and in 8/8680 (0.09%) non-Black patients. These rates were not different statistically. Patients taking concomitant mammalian target of rapamycin (mTOR) inhibitor (e.g., temsirolimus) therapy or a neprilysin inhibitor may be at increased risk for angioedema [see Drug Interactions (7.7) ]. Intestinal Angioedema Intestinal angioedema has been reported in patients treated with ACE inhibitors. These patients presented with abdominal pain (with or without nausea or vomiting); in some cases there was no prior history of facial angioedema and C-1 esterase levels were normal. The angioedema was diagnosed by procedures including abdominal CT scan or ultrasound, or at surgery, and symptoms resolved after stopping the ACE inhibitor. Include intestinal angioedema in the differential diagnosis of patients on ACE inhibitors presenting with abdominal pain. Anaphylactoid Reactions During Desensitization Two patients undergoing desensitizing treatment with hymenoptera venom while receiving ACE inhibitors sustained life-threatening anaphylactoid reactions. In the same patients, these reactions were avoided when ACE inhibitors were temporarily withheld, but they reappeared upon inadvertent rechallenge. Anaphylactoid Reactions During Membrane Exposure Anaphylactoid reactions have been reported in patients dialyzed with high-flux membranes and treated concomitantly with an ACE inhibitor. Anaphylactoid reactions have also been reported in patients undergoing low-density lipoprotein apheresis with dextran sulfate absorption.

5.2 Hepatic Failure and Impaired Liver Function Rarely, ACE inhibitors, including ramipril, have been associated with a syndrome that starts with cholestatic jaundice and progresses to fulminant hepatic necrosis and sometimes death. The mechanism of this syndrome is not understood. Discontinue ramipril if patient develops jaundice or marked elevations of hepatic enzymes. As ramipril is primarily metabolized by hepatic esterases to its active moiety, ramiprilat, patients with impaired liver function could develop markedly elevated plasma levels of ramipril. No formal pharmacokinetic studies have been carried out in hypertensive patients with impaired liver function.

5.3 Renal Impairment As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function may be anticipated in susceptible individuals. In patients with severe congestive heart failure whose renal function may depend on the activity of the renin-angiotensin-aldosterone system, treatment with ACE inhibitors, including ramipril, may be associated with oliguria or progressive azotemia and rarely with acute renal failure or death. In hypertensive patients with unilateral or bilateral renal artery stenosis, increases in blood urea nitrogen and serum creatinine may occur. Experience with another ACE inhibitor suggests that these increases would be reversible upon discontinuation of ramipril and/or diuretic therapy. In such patients, monitor renal function during the first few weeks of therapy. Some hypertensive patients with no apparent pre-existing renal vascular disease have developed increases in blood urea nitrogen and serum creatinine, usually minor and transient, especially when ramipril has been given concomitantly with a diuretic. This is more likely to occur in patients with pre-existing renal impairment. Dosage reduction of ramipril and/or discontinuation of the diuretic may be required.

5.4 Neutropenia and Agranulocytosis In rare instances, treatment with ACE inhibitors may be associated with mild reductions in red blood cell count and hemoglobin content, blood cell or platelet counts. In isolated cases, agranulocytosis, pancytopenia, and bone marrow depression may occur. Hematological reactions to ACE inhibitors are more likely to occur in patients with collagen-vascular disease (e.g., systemic lupus erythematosus, scleroderma) and renal impairment. Consider monitoring white blood cell counts in patients with collagen-vascular disease, especially if the disease is associated with impaired renal function.

5.5 Hypotension General Considerations Ramipril can cause symptomatic hypotension, after either the initial dose or a later dose when the dosage has been increased. Like other ACE inhibitors, ramipril, has been only rarely associated with hypotension in uncomplicated hypertensive patients. Symptomatic hypotension is most likely to occur in patients who have been volume- and/or salt-depleted as a result of prolonged diuretic therapy, dietary salt restriction, dialysis, diarrhea, or vomiting. Correct volume- and salt-depletion before initiating therapy with ramipril. If excessive hypotension occurs, place the patient in a supine position and, if necessary, treat with intravenous infusion of physiological saline. Ramipril treatment usually can be continued following restoration of blood pressure and volume. Heart Failure Post-Myocardial Infarction In patients with heart failure post-myocardial infarction who are currently being treated with a diuretic, symptomatic hypotension occasionally can occur following the initial dose of ramipril. If the initial dose of 2.5 mg ramipril cannot be tolerated, use an initial dose of 1.25 mg ramipril to avoid excessive hypotension. Consider reducing the dose of concomitant diuretic to decrease the incidence of hypotension. Congestive Heart Failure In patients with congestive heart failure, with or without associated renal insufficiency, ACE inhibitor therapy may cause excessive hypotension, which may be associated with oliguria or azotemia and rarely, with acute renal failure and death. In such patients, initiate ramipril therapy under close medical supervision and follow patients closely for the first 2 weeks of treatment and whenever the dose of ramipril or diuretic is increased. Surgery and Anesthesia In patients undergoing surgery or during anesthesia with agents that produce hypotension, ramipril may block angiotensin II formation that would otherwise occur secondary to compensatory renin release. […]

The most common adverse reactions in patients with hypertension included headache, dizziness, fatigue, and cough (6.1) .To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Hypertension Ramipril has been evaluated for safety in over 4000 patients with hypertension; of these, 1230 patients were studied in U.S. controlled trials, and 1107 were studied in foreign controlled trials. Almost 700 of these patients were treated for at least one year. The overall incidence of reported adverse events was similar in ramipril and placebo patients. The most frequent clinical side effects (possibly or probably related to study drug) reported by patients receiving ramipril in placebo-controlled trials were: headache (5.4%), dizziness (2.2%), and fatigue or asthenia (2%), but only the last one was more common in ramipril patients than in patients given placebo. Generally the side effects were mild and transient, and there was no relation to total dosage within the range of 1.25 mg to 20 mg. Discontinuation of therapy because of a side effect was required in approximately 3% of U.S. patients treated with ramipril. The most common reasons for discontinuation were: cough (1%), dizziness (0.5%), and impotence (0.4%). Of observed side effects considered possibly or probably related to study drug that occurred in U.S. placebo-controlled trials in more than 1% of patients treated with ramipril, only asthenia (fatigue) was more common on ramipril than placebo (2% [n=13/651] vs. 1% [n=2/286], respectively). In placebo-controlled trials, there was also an excess of upper respiratory infection and flu syndrome in the ramipril group, not attributed at that time to ramipril. As these studies were carried out before the relationship of cough to ACE inhibitors was recognized, some of these events may represent ramipril-induced cough. In a later 1-year study, increased cough was seen in almost 12% of ramipril patients, with about 4% of patients requiring discontinuation of treatment. Reduction in the Risk of Myocardial Infarction, Stroke, and Death from Cardiovascular Causes HOPE Study Safety data in the Heart Outcomes Prevention Evaluation (HOPE) study were collected as reasons for discontinuation or temporary interruption of treatment. The incidence of cough was similar to that seen in the Acute Infarction Ramipril Efficacy (AIRE) trial. The rate of angioedema was the same as in previous clinical trials [see Warnings and Precautions ( 5.1 )]. Heart Failure Post-Myocardial Infarction AIRE Study Adverse reactions (except laboratory abnormalities) considered possibly/probably related to study drug that occurred in more than 1% of patients and more frequently on ramipril are shown below. The incidences are from the AIRE study. The follow-up time was between 6 and 46 months for this study. Table 1. Percentage of Patients with Adverse Events Possibly/ Probably Related to Study Drug—Placebo-Controlled (AIRE) Mortality Study Adverse Event Placebo (N=982) Ramipril (N=1004) Hypotension 5% 11% Cough increased 4% 8% Dizziness 3% 4% Angina pectoris 2% 3% Nausea 1% 2% Postural hypotension 1% 2% Syncope 1% 2% Vomiting 0.5% 2% Vertigo 0.7% 2% Abnormal kidney function 0.5% 1% Diarrhea 0.4% 1% Other Adverse Reactions Other adverse reactions reported in controlled clinical trials (in less than 1% of ramipril patients), or rarer events seen in post-marketing experience, include the following (in some, a causal relationship to drug is uncertain): Body As a Whole : Anaphylactoid reactions [see Warnings and Precautions (5.1) ] . Cardiovascular : Symptomatic hypotension (reported in 0.5% of patients in U.S. trials) [see Warnings and Precautions (5.5) ] , syncope, and palpitations. Hematologic: Pancytopenia, hemolytic anemia, and thrombocytopenia. Decreases in hemoglobin or hematocrit (a low value and a decrease of 5 g/dL or 5%, respectively) were rare, occurring in 0.4% of patients receiving ramipril alone and in 1.5% of patients receiving ramipril plus a diuretic. Renal: Acute renal failure. Some hypertensive patients with no apparent pre-existing renal disease have developed minor, usually transient, increases in blood urea nitrogen and serum creatinine when taking ramipril, particularly when ramipril was given concomitantly with a diuretic [see Warnings and Precautions (5.3) ] . Angioneurotic Edema: Angioneurotic edema has been reported in 0.3% of patients in U.S. clinical trials of ramipril [see Warnings and Precautions (5.1) ] . Gastrointestinal: Hepatic failure, hepatitis, jaundice, pancreatitis, abdominal pain (sometimes with enzyme changes suggesting pancreatitis), anorexia, constipation, diarrhea, dry mouth, dyspepsia, dysphagia, gastroenteritis, increased salivation, and taste disturbance. Dermatologic: Apparent hypersensitivity reactions (manifested by urticaria, pruritus, or rash, with or without fever), photosensitivity, purpura, onycholysis, pemphigus, pemphigoid, erythema multiforme, toxic epidermal necrolysis, and Stevens-Johnson syndrome. Neurologic and Psychiatric: Anxiety, amnesia, convulsions, depression, hearing loss, insomnia, nervousness, neuralgia, neuropathy, paresthesia, somnolence, tinnitus, tremor, vertigo, and vision disturbances. Miscellaneous: As with other ACE inhibitors, a symptom complex has been reported which may include a positive ANA, an elevated erythrocyte sedimentation rate, arthralgia/arthritis, myalgia, fever, vasculitis, eosinophilia, photosensitivity, rash and other dermatologic manifestations. Additionally, as with other ACE inhibitors, eosinophilic pneumonitis has been reported. Other: Arthralgia, arthritis, dyspnea, edema, epistaxis, impotence, increased sweating, malaise, myalgia, and weight gain. Table 1

6.2 Post-Marketing Experience In addition to adverse reactions reported from clinical trials, there have been rare reports of hypoglycemia reported during ramipril therapy when given to patients concomitantly taking oral hypoglycemic agents or insulin. The causal relationship is unknown.

6.3 Clinical Laboratory Test Findings Creatinine and Blood Urea Nitrogen: Increases in creatinine levels occurred in 1.2% of patients receiving ramipril alone, and in 1.5% of patients receiving ramipril and a diuretic. Increases in blood urea nitrogen levels occurred in 0.5% of patients receiving ramipril alone and in 3% of patients receiving ramipril with a diuretic. None of these increases required discontinuation of treatment. Increases in these laboratory values are more likely to occur in patients with renal insufficiency or those pretreated with a diuretic and, based on experience with other ACE inhibitors, would be expected to be especially likely in patients with renal artery stenosis [see Warnings and Precautions (5.3) ] . As ramipril decreases aldosterone secretion, elevation of serum potassium can occur. Use potassium supplements and potassium sparing diuretics with caution, and monitor the patient’s serum potassium frequently [see Warnings and Precautions (5.8) ] . Hemoglobin and Hematocrit: Decreases in hemoglobin or hematocrit (a low value and a decrease of 5 g/dL or 5%, respectively) were rare, occurring in 0.4% of patients receiving ramipril alone and in 1.5% of patients receiving ramipril plus a diuretic. No U.S. patients discontinued treatment because of decreases in hemoglobin or hematocrit. Other (causal relationships unknown): Clinically important changes in standard laboratory tests were rarely associated with ramipril administration. […]

Diuretics: Possibility of excessive hypotension ( 7.1 ). Lithium: Use with caution (7.4) . Gold: Nitritoid reactions have been reported ( 7.5 ). NSAIDs use may lead to increased risk of renal impairment and loss of antihypertensive effect ( 7.6 ). mTOR inhibitor or neprilysin inhibitor use may increase angioedema risk ( 7.7 )

7.1 Diuretics Patients on diuretics, especially those in whom diuretic therapy was recently instituted, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with ramipril. The possibility of hypotensive effects with ramipril can be minimized by either decreasing or discontinuing the diuretic or increasing the salt intake prior to initiation of treatment with ramipril. If this is not possible, reduce the starting dose [see Dosage and Administration (2) ] .

7.2 Agents Increasing Serum Potassium Coadministration of ramipril with other drugs that raise serum potassium levels may result in hyperkalemia. Monitor serum potassium in such patients.

7.3 Other Agents Affecting RAS In general, avoid combined use of RAS inhibitors. [see Warnings and Precautions (5.7) ] . Do not co-administer aliskiren with ramipril in patients with diabetes [see Contraindications (4) ].

7.4 Lithium Increased serum lithium levels and symptoms of lithium toxicity have been reported in patients receiving ACE inhibitors during therapy with lithium; therefore, frequent monitoring of serum lithium levels is recommended. If a diuretic is also used, the risk of lithium toxicity may be increased.

7.5 Gold Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) have been reported rarely in patients on therapy with injectable gold (sodium aurothiomalate) and concomitant ACE inhibitor therapy including ramipril.

7.6 Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, co-administration of NSAIDs, including selective COX-2 inhibitors, with ACE inhibitors, including ramipril, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving ramipril and NSAID therapy. The antihypertensive effect of ACE inhibitors, including ramipril, may be attenuated by NSAIDs. 7.7 mTOR Inhibitors or Other Drugs Known to Cause Angioedema Patients taking concomitant mTOR inhibitor (e.g., temsirolimus) therapy or a neprilysin inhibitor may be at increased risk for angioedema [see Warnings and Precautions (5.1) ] .

Pregnancy: Discontinue drug if pregnancy is detected ( 5.6 , 8.1) . Nursing mothers: Ramipril use is not recommended in nursing mothers (8.3) . See 17 for PATIENT COUNSELING INFORMATION Revised: 08/2021

8.1 Pregnancy Pregnancy Category D Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death. When pregnancy is detected, discontinue ramipril as soon as possible. These adverse outcomes are usually associated with use of these drugs in the second and third trimester of pregnancy. Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. Appropriate management of maternal hypertension during pregnancy is important to optimize outcomes for both mother and fetus. In the unusual case that there is no appropriate alternative to therapy with drugs affecting the renin-angiotensin system for a particular patient, apprise the mother of the potential risk to the fetus. Perform serial ultrasound examinations to assess the intra-amniotic environment. If oligohydramnios is observed, discontinue ramipril unless it is considered life-saving for the mother. Fetal testing may be appropriate, based on the week of pregnancy. Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury. Closely observe infants with histories of in utero exposure to ramipril for hypotension, oliguria, and hyperkalemia [see Use in Specific Populations (8.4) ] .

8.3 Nursing Mothers Ingestion of a single 10 mg oral dose of ramipril resulted in undetectable amounts of ramipril and its metabolites in breast milk. However, because multiple doses may produce low milk concentrations that are not predictable from a single dose, do not use ramipril in nursing mothers.

8.4 Pediatric Use Neonates with a history of in utero exposure to ramipril: If oliguria or hypotension occurs, direct attention toward support of blood pressure and renal perfusion. Exchange transfusions or dialysis may be required as a means of reversing hypotension and/or substituting for disordered renal function. Ramipril, which crosses the placenta, can be removed from the neonatal circulation by these means, but limited experience has not shown that such removal is central to the treatment of these infants. Safety and effectiveness in pediatric patients have not been established. Irreversible kidney damage has been observed in very young rats given a single dose of ramipril.

8.5 Geriatric Use Of the total number of patients who received ramipril in U.S. clinical studies of ramipril, 11% were ≥65 years of age while 0.2% were ≥75 years of age. No overall differences in effectiveness or safety were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but a greater sensitivity of some older individuals cannot be ruled out. One pharmacokinetic study conducted in hospitalized elderly patients indicated that peak ramiprilat levels and area under the plasma concentration-time curve (AUC) for ramiprilat are higher in older patients.

8.6 Renal Impairment A single-dose pharmacokinetic study was conducted in hypertensive patients with varying degrees of renal impairment who received a single 10 mg dose of ramipril. Patients were stratified into four groups based on initial estimates of creatinine clearance: normal (>80 mL/min), mild impairment (40 to 80 mL/min), moderate impairment (15 to 40 mL/min), and severe impairment (<15 mL/min). On average, the AUC 0-24h for ramiprilat was approximately 1.7-fold higher, 3-fold higher, and 3.2-fold higher in the groups with mild, moderate, and severe renal impairment, respectively, compared to the group with normal renal function. Overall, the results suggest that the starting dose of ramipril should be adjusted downward in patients with moderate-to-severe renal impairment.

Ramipril and ramiprilat inhibit ACE in human subjects and animals. Angiotensin converting enzyme 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. In hypertensive patients with normal renal function treated with ramipril alone for up to 56 weeks, approximately 4% of patients during the trial had an abnormally high serum potassium and an increase from baseline greater than 0.75 mEq/L, and none of the patients had an abnormally low potassium and a decrease from baseline greater than 0.75 mEq/L. In the same study, approximately 2% of patients treated with ramipril and hydrochlorothiazide for up to 56 weeks had abnormally high potassium values and an increase from baseline of 0.75 mEq/L or greater; and approximately 2% had abnormally low values and decreases from baseline of 0.75 mEq/L or greater [see Warnings and Precautions (5.8) ] . Removal of angiotensin II negative feedback on renin secretion leads to increased plasma renin activity. The effect of ramipril on hypertension appears to result at least in part from inhibition of both tissue and circulating ACE activity, thereby reducing angiotensin II formation in tissue and plasma. Angiotensin converting enzyme is identical to kininase, an enzyme that degrades bradykinin. Whether increased levels of bradykinin, a potent vasopressor peptide, play a role in the therapeutic effects of ramipril remains to be elucidated. While the mechanism through which ramipril lowers blood pressure is believed to be primarily suppression of the renin-angiotensin-aldosterone system, ramipril has an antihypertensive effect even in patients with low-renin hypertension. Although ramipril was antihypertensive in all races studied, Black hypertensive patients (usually a low-renin hypertensive population) had a blood pressure lowering response to monotherapy, albeit a smaller average response, than non-Black patients.