Version July 2025
When pregnancy is detected, discontinue therapy as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus.
Hypertension: Oral: Initial: Quinapril 10 mg/hydrochlorothiazide 12.5 mg or quinapril 20 mg/hydrochlorothiazide 12.5 mg once daily; may adjust dose after 2 to 3 weeks of therapy based on BP response. Usual maintenance dose: Quinapril 5 to 40 mg/hydrochlorothiazide 6.25 to 25 mg once daily. Patients already taking quinapril and/or hydrochlorothiazide may be switched to a combination product for individually titrated agents.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
CrCl >30 mL/minute/1.73 m2 or serum creatinine ≤3 mg/dL: No dosage adjustment necessary.
CrCl ≤30 mL/minute/1.73 m2 or serum creatinine >3 mg/dL: Use is not recommended.
There are no dosage adjustments provided in the manufacturer's labeling (has not been studied); use with caution.
Refer to adult dosing; initial dose selection should be cautious, at the low end of dosage range.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Also see individual agents.
1% to 10%:
Central nervous system: Dizziness (5%), drowsiness (1%)
Neuromuscular & skeletal: Weakness (1%)
Renal: Increased blood urea nitrogen (4%), increased serum creatinine (3%)
Respiratory: Cough (3%), bronchitis (1%)
<1%, postmarketing, and/or case reports: Abnormal gait, abnormal hepatic function tests, acute angle-closure glaucoma, acute renal failure, agranulocytosis, albuminuria, alopecia, amnesia, anaphylactoid reaction, anemia, angina pectoris, angioedema, arthralgia, arthritis, ascites, asthma, bradycardia, cardiac arrhythmia, cardiac failure, cellulitis, cerebrovascular accident, cholesterol increased (serum), cholestatic jaundice, cor pulmonale, deep vein thrombosis, diaphoresis, diarrhea, dyspnea, edema, erythema multiforme, esophagitis, exfoliative dermatitis, gastrointestinal hemorrhage, hematuria, hemiplegia, hepatitis, hypercalcemia, hyperkalemia, hypermagnesemia, hypertensive crisis, impotence, increased serum calcium, increased serum cholesterol, increased serum glucose, increased serum triglycerides, increased uric acid, malaise, meningism, myocardial infarction, myopathy, myopia, myositis, nephrosis, nervousness, orthostatic hypotension, palpitations, pancreatitis, paralysis, paresthesia, pemphigus, petechiae, pneumonia, pruritus, pyuria, renal function abnormality, shock, sinusitis, skin photosensitivity, skin rash, tachycardia, thrombocytopenia, urticaria, vasculitis, vertigo, visual disturbance, weight loss, xerostomia
Hypersensitivity to quinapril, hydrochlorothiazide, sulfonamide-derived drugs, or any other component of the formulation; history of angioedema related to previous treatment with an ACE inhibitor; concomitant use with aliskiren in patients with diabetes mellitus; concomitant use or within 36 hours of switching to or from a neprilysin inhibitor (eg, sacubitril); anuria.
Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Note: Although the FDA-approved product labeling states this medication is contraindicated in patients with hypersensitivity to sulfonamide-containing drugs, the scientific basis of this cross-sensitivity has been challenged.
Canadian labeling: Additional contraindications (not in US labeling): Patients who are pregnant, intend to become pregnant, or of childbearing potential and not using adequate contraception; breastfeeding; concomitant use with aliskiren in patients with GFR <60 mL/minute/1.73 m2, hyperkalemia (>5 mmol/L) or heart failure patients with hypotension; concomitant use with ARBs in patients with diabetes mellitus with end organ damage, GFR <60 mL/minute/1.73 m2, hyperkalemia (>5 mmol/L) or heart failure patients with hypotension; concomitant use with ARBs or other ACE inhibitors in diabetic patients with end organ damage; patients with galactose intolerance, congenital lactase deficiency, or glucose-galactose malabsorption syndromes
Concerns related to adverse effects:
• Angioedema: At any time during treatment (especially following first dose) angioedema may occur rarely with ACE inhibitors; it may involve the head and neck (potentially compromising airway) or the intestine (presenting with abdominal pain). Black patients and patients with idiopathic or hereditary angioedema or previous angioedema associated with ACE inhibitor therapy may be at an increased risk. Risk may also be increased with concomitant use of mTOR inhibitor (eg, everolimus) or neprilysin inhibitor (eg, sacubitril) therapy. Prolonged frequent monitoring may be required, especially if tongue, glottis, or larynx are involved because they are associated with airway obstruction. Patients with a history of airway surgery may have a higher risk of airway obstruction. Aggressive early and appropriate management is critical. Use in patients with previous angioedema associated with ACE inhibitor therapy is contraindicated.
• Cholestatic jaundice: A rare toxicity associated with ACE inhibitors includes cholestatic jaundice, which may progress to fulminant hepatic necrosis (some fatal); discontinue if marked elevation of hepatic transaminases or jaundice occurs.
• Cough: An ACE inhibitor cough is a dry, hacking, nonproductive one that usually occurs within the first few months of treatment and should generally resolve within 1 to 4 weeks after discontinuation of the ACE inhibitor. Other causes of cough should be considered (eg, pulmonary congestion in patients with heart failure) and excluded prior to discontinuation.
• Electrolyte disturbances: Hyperkalemia may occur with ACE inhibitors; risk factors include renal impairment, diabetes mellitus, and concomitant use of potassium-sparing diuretics, potassium supplements, and/or potassium-containing salts. Use cautiously, if at all, with these agents and monitor potassium closely. Thiazide diuretics may cause hypokalemia, hypochloremic alkalosis, hypomagnesemia, and hyponatremia. Risk of hypokalemia may be increased in patients with cirrhosis, brisk diuresis, or concomitant use of potassium-lowering agents.
• Gout: In certain patients with a history of gout, a familial predisposition to gout, or chronic renal failure, gout can be precipitated by hydrochlorothiazide. This risk may be increased with doses ≥25 mg (Gurwitz 1997).
• Hematologic effects: Another ACE inhibitor, captopril, has been associated with neutropenia with myeloid hypoplasia and agranulocytosis; anemia and thrombocytopenia have also occurred. Patients with renal impairment are at high risk of developing neutropenia. Patients with both renal impairment and collagen vascular disease (eg, systemic lupus erythematosus) are at an even higher risk of developing neutropenia. Periodically monitor CBC with differential in these patients.
• Hypersensitivity reactions: Anaphylactic/anaphylactoid reactions can occur with ACE inhibitors. Severe anaphylactoid reactions may be seen during hemodialysis (eg, CVVHD) with high-flux dialysis membranes (eg, AN69), and rarely, during low density lipoprotein apheresis with dextran sulfate cellulose. Rare cases of anaphylactoid reactions have been reported in patients undergoing sensitization treatment with hymenoptera (bee, wasp) venom while receiving ACE inhibitors. Hypersensitivity reactions may also occur with hydrochlorothiazide; risk is increased in patients with a history of allergy or bronchial asthma.
• Hypotension/syncope: Symptomatic hypotension with or without syncope can occur with ACE inhibitors (usually with the first several doses); effects are most often observed in volume-depleted patients; correct volume depletion prior to initiation; close monitoring of patient is required especially with initial dosing and dosing increases; blood pressure must be lowered at a rate appropriate for the patient's clinical condition. Although dose reduction may be necessary, hypotension is not a reason for discontinuation of future ACE inhibitor use especially in patients with heart failure where a reduction in systolic blood pressure is a desirable observation. The antihypertensive effects of thiazides may be enhanced in postsympathectomy patients.
• Ocular effects: Hydrochlorothiazide may cause acute transient myopia and acute angle-closure glaucoma.
• Photosensitivity: Photosensitization may occur.
• Renal function deterioration: May be associated with deterioration of renal function and/or increases in serum creatinine, particularly in patients with low renal blood flow (eg, renal artery stenosis, heart failure) whose glomerular filtration rate (GFR) is dependent on efferent arteriolar vasoconstriction by angiotensin II; deterioration may result in oliguria, acute renal failure, and progressive azotemia. Small increases in serum creatinine may occur following initiation; consider discontinuation only in patients with progressive and/or significant deterioration in renal function (Bakris 2000).
• Skin cancer, nonmelanoma: Prolonged use (≥3 years) may increase the risk for squamous cell carcinoma up to 4 times and increase the risk for basal cell carcinoma up to 1.25 times compared to patients not treated with hydrochlorothiazide (Pedersen 2018; Pottegård 2017).
• Sulfonamide (“sulfa”) allergy: The FDA-approved product labeling for many medications containing a sulfonamide chemical group includes a broad contraindication in patients with a prior allergic reaction to sulfonamides. There is a potential for cross-reactivity between members of a specific class (eg, two antibiotic sulfonamides). However, concerns for cross-reactivity have previously extended to all compounds containing the sulfonamide structure (SO2NH2). An expanded understanding of allergic mechanisms indicates cross-reactivity between antibiotic sulfonamides and nonantibiotic sulfonamides may not occur or at the very least this potential is extremely low (Brackett 2004; Johnson 2005; Slatore 2004; Tornero 2004). In particular, mechanisms of cross-reaction due to antibody production (anaphylaxis) are unlikely to occur with nonantibiotic sulfonamides. T-cell-mediated (type IV) reactions (eg, maculopapular rash) are less well understood and it is not possible to completely exclude this potential based on current insights. In cases where prior reactions were severe (Stevens-Johnson syndrome/TEN), some clinicians choose to avoid exposure to these classes.
Disease-related concerns:
• Adrenal insufficiency: Avoid use of diuretics for treatment of elevated blood pressure in patients with primary adrenal insufficiency (Addison disease). Adjustment of glucocorticoid/mineralocorticoid therapy and/or use of other antihypertensive agents is preferred to treat hypertension (Bornstein 2016; Inder 2015).
• Aortic stenosis: Use with caution in patients with severe aortic stenosis; quinapril may reduce coronary perfusion resulting in ischemia.
• Bariatric surgery: Dehydration: Avoid diuretics in the immediate postoperative period after bariatric surgery; electrolyte disturbances and dehydration may occur. Diuretics may be resumed, if indicated, once oral fluid intake goals are met (Ziegler 2009).
• Cardiovascular disease: Initiation of ACE inhibitor therapy in patients with ischemic heart disease or cerebrovascular disease warrants close observation due to the potential consequences posed by falling blood pressure (eg, MI, stroke). Fluid replacement, if needed, may restore blood pressure; therapy may then be resumed. Discontinue therapy in patients whose hypotension recurs.
• Collagen vascular disease: Use quinapril with caution in patients with collagen vascular disease especially with concomitant renal impairment; may be at increased risk for hematologic toxicity.
• Diabetes: Use hydrochlorothiazide with caution in patients with prediabetes or diabetes mellitus; may see a change in glucose control.
• Hepatic impairment: Use caution in patients with hepatic impairment. In progressive or severe liver disease, avoid electrolyte and acid/base imbalances that might lead to hepatic encephalopathy/coma.
• Hypercalcemia: Thiazide diuretics may decrease renal calcium excretion; monitor serum calcium in patients with hypercalcemia.
• Hypercholesterolemia: Use with caution in patients with moderate or high cholesterol concentrations; increased cholesterol and triglyceride levels have been reported with thiazides.
• Hypertrophic cardiomyopathy with left ventricular outflow tract obstruction: Use quinapril with caution in patients with hypertrophic cardiomyopathy and left ventricular outflow tract obstruction because reduction in afterload may worsen symptoms associated with this condition (AHA/ACC [Ommen 2024]).
• Parathyroid disease: Thiazide diuretics reduce calcium excretion; pathologic changes in the parathyroid glands with hypercalcemia and hypophosphatemia have been observed with prolonged use; should be discontinued prior to testing for parathyroid function.
• Renal artery stenosis: Use quinapril with caution in patients with unstented unilateral/bilateral renal artery stenosis. When unstented unilateral or bilateral renal artery stenosis is present or suspected, use is generally avoided due to the elevated risk of deterioration in renal function unless possible benefits outweigh risks.
• Renal impairment: Use with caution in pre-existing renal impairment; dosage adjustment may be needed. Avoid rapid dosage escalation which may lead to further renal impairment. Cumulative effects of hydrochlorothiazide may develop, including azotemia, in patients with impaired renal function. Avoid hydrochlorothiazide in severe renal disease (ineffective). Contraindicated in anuric patients.
• Systemic lupus erythematosus: Thiazides may exacerbate or activate systemic lupus erythematosus (SLE).
Special populations:
• Black patients: Effectiveness of ACE inhibitors is less in Black patients than in non-Black patients. In addition, ACE inhibitors cause a higher rate of angioedema in Black patients than in non-Black patients.
• Pregnancy: [US Boxed Warning]: Drugs that act on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as possible once pregnancy is detected.
Other warnings/precautions:
• Surgery: In patients on chronic ACE inhibitor therapy, intraoperative hypotension may occur with induction and maintenance of general anesthesia; use with caution before, during, or immediately after major surgery. Cardiopulmonary bypass, intraoperative blood loss, or vasodilating anesthesia increases endogenous renin release. Use of ACE inhibitors perioperatively will blunt angiotensin II formation and may result in hypotension. However, discontinuation of therapy prior to surgery is controversial. If continued preoperatively, avoidance of hypotensive agents during surgery is prudent (Hillis 2011). In addition, if given the morning of surgery, hydrochlorothiazide may render the patient volume depleted and blood pressure may be labile during general anesthesia.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, oral:
Accuretic: Quinapril 10 mg and hydrochlorothiazide 12.5 mg (90s), Quinapril 20 mg and hydrochlorothiazide 12.5 mg (90s), Quinapril 20 mg and hydrochlorothiazide 25 mg (90s [DSC])
Generic: Quinapril 10 mg and hydrochlorothiazide 12.5 mg (90s), Quinapril 20 mg and hydrochlorothiazide 12.5 mg (90s), Quinapril 20 mg and hydrochlorothiazide 25 mg (90s)
Yes
Tablets (Accuretic Oral)
10-12.5 mg (per each): $6.02
20-12.5 mg (per each): $6.02
Tablets (Quinapril-hydroCHLOROthiazide Oral)
10-12.5 mg (per each): $5.70
20-12.5 mg (per each): $5.76
20-25 mg (per each): $5.88
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, oral:
Accuretic: Quinapril 20 mg and hydrochlorothiazide 12.5 mg [DSC], Quinapril 20 mg and hydrochlorothiazide 25 mg [DSC]
Auro-Quinapril HCTZ: Quinapril 10 mg and hydrochlorothiazide 12.5 mg, Quinapril 20 mg and hydrochlorothiazide 12.5 mg, Quinapril 20 mg and hydrochlorothiazide 25 mg
Generic: Quinapril 10 mg and hydrochlorothiazide 12.5 mg, Quinapril 20 mg and hydrochlorothiazide 12.5 mg, Quinapril 20 mg and hydrochlorothiazide 25 mg
Administer without regard to food.
Hypertension: Management of hypertension.
Beers Criteria: Diuretics (hydrochlorothiazide) are identified in the Beers Criteria as potentially inappropriate medications to be used with caution in patients 65 years and older due to the potential to cause or exacerbate syndrome of inappropriate antidiuretic hormone secretion (SIADH) or hyponatremia; monitor sodium concentration closely when initiating or adjusting the dose in older adults (Beers Criteria [AGS 2023]).
Refer to individual components.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Agents with Clinically Relevant Anticholinergic Effects: May increase serum concentration of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Ajmaline: Sulfonamides may increase adverse/toxic effects of Ajmaline. Specifically, the risk for cholestasis may be increased. Risk C: Monitor
Alcohol (Ethyl): May increase orthostatic hypotensive effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Alfuzosin: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Aliskiren: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Aliskiren may increase nephrotoxic effects of Angiotensin-Converting Enzyme Inhibitors. Aliskiren may increase hypotensive effects of Angiotensin-Converting Enzyme Inhibitors. Management: Aliskiren use with ACEIs or ARBs in patients with diabetes is contraindicated. Combined use in other patients should be avoided, particularly when CrCl is less than 60 mL/min. If combined, monitor potassium, creatinine, and blood pressure closely. Risk D: Consider Therapy Modification
Allopurinol: Angiotensin-Converting Enzyme Inhibitors may increase hypersensitivity effects of Allopurinol. Risk C: Monitor
Allopurinol: Thiazide and Thiazide-Like Diuretics may increase hypersensitivity effects of Allopurinol. Risk C: Monitor
Alteplase: Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Alteplase. Specifically, the risk for angioedema may be increased. Risk C: Monitor
Amifostine: Blood Pressure Lowering Agents may increase hypotensive effects of Amifostine. Management: When used at chemotherapy doses, hold blood pressure lowering medications for 24 hours before amifostine administration. If blood pressure lowering therapy cannot be held, do not administer amifostine. Use caution with radiotherapy doses of amifostine. Risk D: Consider Therapy Modification
Aminolevulinic Acid (Systemic): Photosensitizing Agents may increase photosensitizing effects of Aminolevulinic Acid (Systemic). Risk X: Avoid
Aminolevulinic Acid (Topical): Photosensitizing Agents may increase photosensitizing effects of Aminolevulinic Acid (Topical). Risk C: Monitor
Amphetamines: May decrease antihypertensive effects of Antihypertensive Agents. Risk C: Monitor
Angiotensin II Receptor Blockers: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Angiotensin II Receptor Blockers may increase serum concentration of Angiotensin-Converting Enzyme Inhibitors. Management: Use of telmisartan and ramipril is not recommended. It is not clear if any other combination of an ACE inhibitor and an ARB would be any safer. Consider alternatives when possible. Monitor blood pressure, renal function, and potassium if combined. Risk D: Consider Therapy Modification
Angiotensin II: Angiotensin-Converting Enzyme Inhibitors may increase therapeutic effects of Angiotensin II. Risk C: Monitor
Antidiabetic Agents: Hyperglycemia-Associated Agents may decrease therapeutic effects of Antidiabetic Agents. Risk C: Monitor
Antidiabetic Agents: Thiazide and Thiazide-Like Diuretics may decrease therapeutic effects of Antidiabetic Agents. Risk C: Monitor
Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may increase hypotensive effects of Antipsychotic Agents (Second Generation [Atypical]). Risk C: Monitor
Aprotinin: May decrease antihypertensive effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Arginine: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Arsenic Trioxide: Thiazide and Thiazide-Like Diuretics may increase hypotensive effects of Arsenic Trioxide. Thiazide and Thiazide-Like Diuretics may increase QTc-prolonging effects of Arsenic Trioxide. Management: When possible, avoid concurrent use of arsenic trioxide with drugs that can cause electrolyte abnormalities, such as the thiazide and thiazide-like diuretics. Risk D: Consider Therapy Modification
AzaTHIOprine: Angiotensin-Converting Enzyme Inhibitors may increase myelosuppressive effects of AzaTHIOprine. Risk C: Monitor
Barbiturates: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Benperidol: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Beta2-Agonists: May increase hypokalemic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Bile Acid Sequestrants: May decrease absorption of Thiazide and Thiazide-Like Diuretics. Management: Separate administration of bile acid sequestrants and oral thiazide diuretics by at least 4 hours. Monitor for decreased therapeutic effects of thiazide diuretics if coadministered with a bile acid sequestrant. Risk D: Consider Therapy Modification
Brigatinib: May decrease antihypertensive effects of Antihypertensive Agents. Brigatinib may increase bradycardic effects of Antihypertensive Agents. Risk C: Monitor
Brimonidine (Topical): May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Bromperidol: May decrease hypotensive effects of Blood Pressure Lowering Agents. Blood Pressure Lowering Agents may increase hypotensive effects of Bromperidol. Risk X: Avoid
Calcium Salts: Thiazide and Thiazide-Like Diuretics may increase serum concentration of Calcium Salts. Risk C: Monitor
Cardiac Glycosides: Thiazide and Thiazide-Like Diuretics may increase adverse/toxic effects of Cardiac Glycosides. Specifically, cardiac glycoside toxicity may be enhanced by the hypokalemic and hypomagnesemic effect of thiazide diuretics. Risk C: Monitor
Corticosteroids (Systemic): May increase hypokalemic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
CycloPHOSphamide: Thiazide and Thiazide-Like Diuretics may increase adverse/toxic effects of CycloPHOSphamide. Specifically, granulocytopenia may be enhanced. Risk C: Monitor
Dapoxetine: May increase orthostatic hypotensive effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Desmopressin: Hyponatremia-Associated Agents may increase hyponatremic effects of Desmopressin. Risk C: Monitor
Dexketoprofen: May increase adverse/toxic effects of Sulfonamides. Risk C: Monitor
Dexmethylphenidate: May decrease therapeutic effects of Antihypertensive Agents. Risk C: Monitor
Diacerein: May increase therapeutic effects of Diuretics. Specifically, the risk for dehydration or hypokalemia may be increased. Risk C: Monitor
Diazoxide Choline: May increase adverse/toxic effects of Thiazide and Thiazide-Like Diuretics. Specifically, the hyperglycemic and hyperuricemic effects may be increased. Risk C: Monitor
Diazoxide: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Diazoxide: Thiazide and Thiazide-Like Diuretics may increase adverse/toxic effects of Diazoxide. Risk C: Monitor
Dichlorphenamide: Thiazide and Thiazide-Like Diuretics may increase hypokalemic effects of Dichlorphenamide. Risk C: Monitor
Dipeptidyl Peptidase-IV Inhibitors: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Specifically, the risk of angioedema may be increased. Risk C: Monitor
Dofetilide: HydroCHLOROthiazide may increase QTc-prolonging effects of Dofetilide. HydroCHLOROthiazide may increase serum concentration of Dofetilide. Risk X: Avoid
Drospirenone-Containing Products: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
DULoxetine: Blood Pressure Lowering Agents may increase hypotensive effects of DULoxetine. Risk C: Monitor
EPINEPHrine (Systemic): Diuretics may increase arrhythmogenic effects of EPINEPHrine (Systemic). Diuretics may decrease vasopressor effects of EPINEPHrine (Systemic). Risk C: Monitor
Everolimus: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Specifically, the risk of angioedema may be increased. Risk C: Monitor
Ferric Gluconate: Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Ferric Gluconate. Risk C: Monitor
Ferric Hydroxide Polymaltose Complex: Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Ferric Hydroxide Polymaltose Complex. Specifically, the risk for angioedema or allergic reactions may be increased. Risk C: Monitor
Finerenone: Angiotensin-Converting Enzyme Inhibitors may increase hyperkalemic effects of Finerenone. Risk C: Monitor
Flunarizine: May increase therapeutic effects of Antihypertensive Agents. Risk C: Monitor
Gelatin (Succinylated): Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Gelatin (Succinylated). Specifically, the risk of a paradoxical hypotensive reaction may be increased. Risk C: Monitor
Grass Pollen Allergen Extract (5 Grass Extract): Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Grass Pollen Allergen Extract (5 Grass Extract). Specifically, ACE inhibitors may increase the risk of severe allergic reaction to Grass Pollen Allergen Extract (5 Grass Extract). Risk X: Avoid
Heparin: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Heparins (Low Molecular Weight): May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Herbal Products with Blood Pressure Increasing Effects: May decrease antihypertensive effects of Antihypertensive Agents. Risk C: Monitor
Herbal Products with Blood Pressure Lowering Effects: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Hypotension-Associated Agents: Blood Pressure Lowering Agents may increase hypotensive effects of Hypotension-Associated Agents. Risk C: Monitor
Icatibant: May decrease antihypertensive effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Iloperidone: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Indoramin: May increase hypotensive effects of Antihypertensive Agents. Risk C: Monitor
Ipragliflozin: May increase adverse/toxic effects of Thiazide and Thiazide-Like Diuretics. Specifically, the risk for intravascular volume depletion may be increased. Risk C: Monitor
Iron Dextran Complex: Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Iron Dextran Complex. Specifically, patients receiving an ACE inhibitor may be at an increased risk for anaphylactic-type reactions. Risk C: Monitor
Isocarboxazid: May increase antihypertensive effects of Antihypertensive Agents. Risk X: Avoid
Isocarboxazid: May increase hypotensive effects of Diuretics. Risk X: Avoid
Ivabradine: Thiazide and Thiazide-Like Diuretics may increase arrhythmogenic effects of Ivabradine. Risk C: Monitor
Lanthanum: May decrease serum concentration of Angiotensin-Converting Enzyme Inhibitors. Management: Administer angiotensin-converting enzyme (ACE) inhibitors at least two hours before or after lanthanum. Risk D: Consider Therapy Modification
Levodopa-Foslevodopa: Blood Pressure Lowering Agents may increase hypotensive effects of Levodopa-Foslevodopa. Risk C: Monitor
Levosulpiride: Thiazide and Thiazide-Like Diuretics may increase adverse/toxic effects of Levosulpiride. Risk X: Avoid
Licorice: May increase hypokalemic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Lithium: Angiotensin-Converting Enzyme Inhibitors may increase serum concentration of Lithium. Management: Lithium dosage reductions will likely be needed following the addition of an ACE inhibitor. Monitor for increased concentrations/toxic effects of lithium if an ACE inhibitor is initiated/dose increased, or if switching between ACE inhibitors. Risk D: Consider Therapy Modification
Lithium: Thiazide and Thiazide-Like Diuretics may decrease excretion of Lithium. Management: Reduce the lithium dose if coadministered with thiazide or thiazide-like diuretics. Monitor serum lithium levels during coadministration with thiazide and thiazide-like diuretics. Risk D: Consider Therapy Modification
Loop Diuretics: May increase hypotensive effects of Angiotensin-Converting Enzyme Inhibitors. Loop Diuretics may increase nephrotoxic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Loop Diuretics: May increase hypotensive effects of Antihypertensive Agents. Risk C: Monitor
Lormetazepam: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Mecamylamine: Thiazide and Thiazide-Like Diuretics may increase adverse/toxic effects of Mecamylamine. Management: Consider avoiding the use of mecamylamine and thiazide diuretics. If combined, mecamylamine prescribing information suggests reducing the mecamylamine dose by 50% in order to avoid excessive hypotension. Risk D: Consider Therapy Modification
Metergoline: May decrease antihypertensive effects of Blood Pressure Lowering Agents. Blood Pressure Lowering Agents may increase orthostatic hypotensive effects of Metergoline. Risk C: Monitor
Methenamine: Thiazide and Thiazide-Like Diuretics may decrease therapeutic effects of Methenamine. Risk C: Monitor
Methotrexate: HydroCHLOROthiazide may increase nephrotoxic effects of Methotrexate. Risk C: Monitor
Methoxsalen (Systemic): Photosensitizing Agents may increase photosensitizing effects of Methoxsalen (Systemic). Risk C: Monitor
Methylphenidate: May decrease antihypertensive effects of Antihypertensive Agents. Risk C: Monitor
Molsidomine: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Multivitamins/Fluoride (with ADE): May increase hypercalcemic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Multivitamins/Minerals (with ADEK, Folate, Iron): Thiazide and Thiazide-Like Diuretics may increase hypercalcemic effects of Multivitamins/Minerals (with ADEK, Folate, Iron). Risk C: Monitor
Multivitamins/Minerals (with AE, No Iron): Thiazide and Thiazide-Like Diuretics may increase serum concentration of Multivitamins/Minerals (with AE, No Iron). Specifically, thiazide diuretics may decrease the excretion of calcium, and continued concomitant use can also result in metabolic alkalosis. Risk C: Monitor
Naftopidil: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Neuromuscular-Blocking Agents (Nondepolarizing): Thiazide and Thiazide-Like Diuretics may increase neuromuscular-blocking effects of Neuromuscular-Blocking Agents (Nondepolarizing). Risk C: Monitor
Nicergoline: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Nicorandil: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Nicorandil: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Nitroprusside: Blood Pressure Lowering Agents may increase hypotensive effects of Nitroprusside. Risk C: Monitor
Nonsteroidal Anti-Inflammatory Agents (Topical): May decrease therapeutic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Nonsteroidal Anti-Inflammatory Agents (Topical): May decrease therapeutic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Nonsteroidal Anti-Inflammatory Agents: May decrease antihypertensive effects of Angiotensin-Converting Enzyme Inhibitors. Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Nonsteroidal Anti-Inflammatory Agents. Specifically, the combination may result in a significant decrease in renal function. Risk C: Monitor
Nonsteroidal Anti-Inflammatory Agents: May decrease therapeutic effects of Thiazide and Thiazide-Like Diuretics. Thiazide and Thiazide-Like Diuretics may increase nephrotoxic effects of Nonsteroidal Anti-Inflammatory Agents. Risk C: Monitor
Obinutuzumab: May increase hypotensive effects of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Risk D: Consider Therapy Modification
Opioid Agonists: May increase adverse/toxic effects of Diuretics. Opioid Agonists may decrease therapeutic effects of Diuretics. Risk C: Monitor
Palopegteriparatide: Thiazide and Thiazide-Like Diuretics may increase therapeutic effects of Palopegteriparatide. Thiazide and Thiazide-Like Diuretics may decrease therapeutic effects of Palopegteriparatide. Risk C: Monitor
Pentoxifylline: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Perazine: May increase hypotensive effects of Antihypertensive Agents. Risk C: Monitor
Pholcodine: Blood Pressure Lowering Agents may increase hypotensive effects of Pholcodine. Risk C: Monitor
Phosphodiesterase 5 Inhibitors: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Piperacillin: May increase hypokalemic effects of Diuretics. Risk C: Monitor
Polyethylene Glycol-Electrolyte Solution: Angiotensin-Converting Enzyme Inhibitors may increase nephrotoxic effects of Polyethylene Glycol-Electrolyte Solution. Risk C: Monitor
Polyethylene Glycol-Electrolyte Solution: Diuretics may increase nephrotoxic effects of Polyethylene Glycol-Electrolyte Solution. Risk C: Monitor
Porfimer: Photosensitizing Agents may increase photosensitizing effects of Porfimer. Risk X: Avoid
Potassium Salts: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Potassium-Sparing Diuretics: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Prazosin: Antihypertensive Agents may increase hypotensive effects of Prazosin. Risk C: Monitor
Pregabalin: Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Pregabalin. Specifically, the risk of angioedema may be increased. Risk C: Monitor
Promazine: Thiazide and Thiazide-Like Diuretics may increase QTc-prolonging effects of Promazine. Risk X: Avoid
Prostacyclin Analogues: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Quinagolide: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Racecadotril: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Specifically, the risk for angioedema may be increased with this combination. Risk C: Monitor
Ranolazine: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Reboxetine: May increase hypokalemic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Sacubitril: Angiotensin-Converting Enzyme Inhibitors may increase adverse/toxic effects of Sacubitril. Specifically, the risk of angioedema may be increased with this combination. Risk X: Avoid
Salicylates: May decrease therapeutic effects of Angiotensin-Converting Enzyme Inhibitors. Salicylates may increase nephrotoxic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Selective Serotonin Reuptake Inhibitor: May increase hyponatremic effects of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Silodosin: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Sirolimus Products: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Specifically, the risk for angioedema may be increased. Risk C: Monitor
Sodium Phosphates: Angiotensin-Converting Enzyme Inhibitors may increase nephrotoxic effects of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Risk C: Monitor
Sodium Phosphates: Diuretics may increase nephrotoxic effects of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Risk C: Monitor
Sotagliflozin: HydroCHLOROthiazide may decrease therapeutic effects of Sotagliflozin. Sotagliflozin may decrease serum concentration of HydroCHLOROthiazide. Risk C: Monitor
Sparsentan: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Risk X: Avoid
Tacrolimus (Systemic): Angiotensin-Converting Enzyme Inhibitors may increase hyperkalemic effects of Tacrolimus (Systemic). Risk C: Monitor
Temsirolimus: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Specifically, the risk of angioedema may be increased. Risk C: Monitor
Terazosin: Antihypertensive Agents may increase hypotensive effects of Terazosin. Risk C: Monitor
Tetracyclines: Quinapril may decrease serum concentration of Tetracyclines. Risk C: Monitor
Tolvaptan: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Risk C: Monitor
Topiramate: Thiazide and Thiazide-Like Diuretics may increase hypokalemic effects of Topiramate. Thiazide and Thiazide-Like Diuretics may increase serum concentration of Topiramate. Risk C: Monitor
Toremifene: Thiazide and Thiazide-Like Diuretics may increase hypercalcemic effects of Toremifene. Risk C: Monitor
Trimethoprim: May increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Management: Consider avoiding coadministration if possible. If combined, monitor serum potassium closely, particularly for patients with other risk factors (eg, renal impairment, older age, and other medications that increase potassium. Risk X: Avoid
Urapidil: And Angiotensin-Converting Enzyme Inhibitors may interact via an unclear mechanism. Management: Avoid concomitant use of urapidil and angiotensin-converting enzyme (ACE) inhibitors. Risk D: Consider Therapy Modification
Urokinase: May increase adverse/toxic effects of Angiotensin-Converting Enzyme Inhibitors. Specifically, the risk of angioedema may be increased. Risk C: Monitor
Verteporfin: Photosensitizing Agents may increase photosensitizing effects of Verteporfin. Risk C: Monitor
Vitamin D Analogs: Thiazide and Thiazide-Like Diuretics may increase hypercalcemic effects of Vitamin D Analogs. Risk C: Monitor
See individual agents.
[US Boxed Warning]: Drugs that act on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as possible once pregnancy is detected. Also see individual agents.
Quinapril and thiazide diuretics are present in breast milk. Due to the potential for serious adverse reactions in the breastfeeding infant, the manufacturer recommends a decision be made whether to discontinue breastfeeding or to discontinue the drug, taking into account the importance of treatment to the mother.
Blood pressure; BUN, serum creatinine, and electrolytes; CBC with differential periodically (more frequently if patient has collagen vascular disease and/or renal impairment); visual acuity, ocular pain.
Quinapril: Prevents conversion of angiotensin I to angiotensin II, resulting in lower levels of angiotensin II, which causes an increase in plasma renin activity and a reduction in aldosterone secretion. A CNS mechanism may also be involved in hypotensive effect as angiotensin II increases adrenergic outflow from CNS. Vasoactive kallikreins may be decreased in conversion to active hormones by ACE inhibitors, thus reducing blood pressure.
Hydrochlorothiazide: Inhibits sodium reabsorption in the distal tubules, causing increased excretion of sodium and water as well as potassium and hydrogen ions.
See individual agents.
