Hydrochlorothiazide/Quinapril hydrochloride

Description

Quinapril hydrochloride and hydrochlorothiazide is a fixed-combination tablet that incorporates an angiotensin-converting enzyme (ACE) inhibitor, quinapril hydrochloride, and a thiazide diuretic, hydrochlorothiazide. Quinapril hydrochloride USP is chemically defined as [3S-[2R*(R*), 3R*]]-2-[2-[1-(ethoxycarbonyl)-3-phenylpropylamino]-1-oxopropyl]-1,2,3,4-tetrahydro-3-isoquinoline-carboxylic acid, monohydrochloride, with a molecular formula of C25H30N2O5·HCl. It appears as a white to off-white powder, occasionally exhibiting a pink cast, and is freely soluble in aqueous solvents.

Hydrochlorothiazide USP is chemically described as 6-Chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide, with a molecular formula of C7H8ClN3O4S2. This compound is a white to off-white, practically odorless crystalline powder that is slightly soluble in water, freely soluble in sodium hydroxide solution, n-butylamine, and dimethylformamide, sparingly soluble in methanol, and insoluble in ether, chloroform, and dilute mineral acids.

Quinapril hydrochloride and hydrochlorothiazide is available for oral administration as fixed combination tablets in three strengths: 10 mg/12.5 mg, containing 10 mg of quinapril hydrochloride USP and 12.5 mg of hydrochlorothiazide USP; 20 mg/12.5 mg, containing 20 mg of quinapril hydrochloride USP and 12.5 mg of hydrochlorothiazide USP; and 20 mg/25 mg, containing 20 mg of quinapril hydrochloride USP and 25 mg of hydrochlorothiazide USP. Inactive ingredients include crospovidone, iron oxide red, lecithin, magnesium carbonate, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, povidone, talc, titanium dioxide, and xanthan gum.

Uses and Indications

Quinapril hydrochloride and hydrochlorothiazide tablets are indicated for the treatment of hypertension to lower blood pressure. Effective management of high blood pressure is essential for reducing the risk of both fatal and nonfatal cardiovascular events, particularly strokes and myocardial infarctions.

Control of hypertension should be integrated into a comprehensive cardiovascular risk management strategy, which includes lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. It is important to note that many patients may require a combination of antihypertensive medications to achieve their blood pressure goals.

Numerous antihypertensive agents have demonstrated efficacy in randomized controlled trials, showing a reduction in cardiovascular morbidity and mortality, with blood pressure reduction being a significant contributor to these benefits. The most substantial cardiovascular outcome benefit observed is a decrease in the risk of stroke, alongside reductions in myocardial infarction and cardiovascular mortality.

Elevated systolic or diastolic blood pressure is associated with increased cardiovascular risk, and even modest reductions in severe hypertension can yield considerable benefits. The relative risk reduction from blood pressure lowering is consistent across various populations with differing absolute risks, with patients at higher risk—such as those with diabetes or hyperlipidemia—experiencing greater absolute benefits.

It is important to recognize that some antihypertensive medications may exhibit diminished blood pressure-lowering effects as monotherapy in black patients, and many of these agents have additional approved indications for conditions such as angina, heart failure, or diabetic kidney disease. This fixed combination of quinapril hydrochloride and hydrochlorothiazide is not indicated for the initial therapy of hypertension.

Dosage and Administration

Quinapril is administered orally as a once-daily dose, with effective dosing ranging from 10 mg to 80 mg. Hydrochlorothiazide is also administered orally, with effective doses between 12.5 mg and 50 mg.

In combination therapy, quinapril can be dosed from 2.5 mg to 40 mg, while hydrochlorothiazide can be dosed from 6.25 mg to 25 mg. Higher doses of both components may enhance antihypertensive effects. For patients whose blood pressure is not adequately controlled with quinapril monotherapy, quinapril hydrochloride and hydrochlorothiazide tablets are available in strengths of 10 mg/12.5 mg or 20 mg/12.5 mg.

Further increases in either or both components should be based on clinical response. It is recommended that the hydrochlorothiazide dose not be increased until 2 to 3 weeks have elapsed. For patients experiencing significant potassium loss while on 25 mg of daily hydrochlorothiazide, switching to quinapril hydrochloride and hydrochlorothiazide tablets at 10 mg/12.5 mg or 20 mg/12.5 mg may provide better blood pressure control with reduced electrolyte disturbance.

Patients who are adequately managed with 20 mg of quinapril and 25 mg of hydrochlorothiazide without significant electrolyte disturbances may be prescribed quinapril hydrochloride and hydrochlorothiazide tablets at a strength of 20 mg/25 mg.

Contraindications

Quinapril hydrochloride and hydrochlorothiazide tablets are contraindicated in patients with a known hypersensitivity to quinapril or hydrochlorothiazide, as well as in those with a history of angioedema associated with prior ACE inhibitor therapy. The use of this product is also contraindicated in patients with anuria or hypersensitivity to sulfonamide-derived drugs due to the hydrochlorothiazide component. Additionally, co-administration with aliskiren is contraindicated in patients with diabetes.

Warnings and Precautions

Patients receiving ACE inhibitors, including quinapril hydrochloride and hydrochlorothiazide, may experience a range of adverse reactions, some of which can be serious.

Anaphylactoid and Angioedema Reactions Angioedema affecting the face, extremities, lips, tongue, glottis, and larynx has been reported in patients treated with ACE inhibitors. In cases where laryngeal stridor or angioedema of the face, tongue, or glottis occurs, it is imperative to discontinue treatment with quinapril hydrochloride and hydrochlorothiazide immediately. Patients should receive treatment in accordance with established medical protocols. Emergency therapy, including subcutaneous epinephrine solution (1:1000, 0.3 to 0.5 mL), should be administered promptly if there is involvement of the tongue, glottis, or larynx that may lead to airway obstruction. Additionally, intestinal angioedema has been documented, with symptoms resolving upon cessation of the ACE inhibitor.

History of Angioedema Patients with a prior history of angioedema unrelated to ACE inhibitor therapy may be at an increased risk for angioedema when treated with an ACE inhibitor.

Hepatic and Renal Considerations Patients receiving ACE inhibitors who develop jaundice or significant elevations in hepatic enzymes should discontinue the medication and seek appropriate medical follow-up. Quinapril hydrochloride and hydrochlorothiazide can also induce symptomatic hypotension; in cases of excessive hypotension, patients should be placed in a supine position and may require intravenous infusion of normal saline. Renal function must be monitored during the initial weeks of therapy, particularly in patients with renal artery stenosis or severe renal disease.

Neutropenia and Agranulocytosis Periodic monitoring of white blood cell counts is advisable for patients with collagen vascular disease and/or renal disease due to the risk of neutropenia or agranulocytosis.

Fetal Toxicity In pregnant patients, quinapril hydrochloride and hydrochlorothiazide should be discontinued as soon as pregnancy is confirmed, as medications that act directly on the renin-angiotensin system can cause injury or death to the developing fetus.

Serum Electrolyte Monitoring Serum electrolytes should be monitored periodically, especially in patients with renal insufficiency, diabetes mellitus, or those taking concomitant medications that may elevate serum potassium levels.

Laboratory Testing It is recommended that therapy with quinapril hydrochloride and hydrochlorothiazide be interrupted for several days prior to conducting tests of parathyroid function to ensure accurate results.

Emergency Protocols Healthcare professionals should instruct patients to seek emergency medical assistance if they experience laryngeal stridor or angioedema of the face, tongue, or glottis. In such instances, treatment with quinapril hydrochloride and hydrochlorothiazide must be discontinued immediately. Furthermore, if jaundice or significant elevations in hepatic enzymes occur, the ACE inhibitor should be stopped, and appropriate medical follow-up should be initiated.

Side Effects

Common adverse reactions observed in clinical trials (≥ 1% incidence) include headache (6.7%), dizziness (4.8%), coughing (3.2%), fatigue (2.9%), myalgia (2.4%), viral infection (1.9%), rhinitis (2%), nausea and/or vomiting (1.8%), abdominal pain (1.7%), back pain (1.5%), diarrhea (1.4%), upper respiratory infection (1.3%), insomnia (1.2%), somnolence (1.2%), bronchitis (1.2%), dyspepsia (1.2%), asthenia (1.1%), pharyngitis (1.1%), vasodilatation (1%), vertigo (1%), and chest pain (1%).

Clinical adverse experiences occurring with a frequency of ≥ 0.5% to < 1% include a range of symptoms across various systems. Body as a whole reactions include asthenia and malaise. Cardiovascular events reported include palpitations, tachycardia, heart failure, hyperkalemia, myocardial infarction, cerebrovascular accident, hypertensive crisis, angina pectoris, orthostatic hypotension, and cardiac rhythm disturbances. Gastrointestinal issues noted are dry mouth or throat, gastrointestinal hemorrhage, pancreatitis, and abnormal liver function tests. Nervous/psychiatric reactions include nervousness, vertigo, and paresthesia. Respiratory adverse reactions consist of sinusitis and dyspnea. Integumentary reactions include pruritus, increased sweating, erythema multiforme, exfoliative dermatitis, photosensitivity reactions, alopecia, and pemphigus. Urogenital system reactions include acute renal failure and impotence. Other notable reactions include agranulocytosis, thrombocytopenia, and arthralgia.

Angioedema has been reported in 0.1% of patients receiving quinapril.

Postmarketing experience has revealed additional adverse reactions. Body as a whole reactions include shock, accidental injury, neoplasm, cellulitis, ascites, generalized edema, hernia, and anaphylactoid reactions. Cardiovascular system reactions include bradycardia, cor pulmonale, vasculitis, and deep thrombosis. Digestive system reactions include gastrointestinal carcinoma, cholestatic jaundice, hepatitis, esophagitis, vomiting, and diarrhea. Eye disorders reported include acute myopia and acute angle closure glaucoma. Hemic system reactions include anemia. Metabolic and nutritional disorders include weight loss. Musculoskeletal system reactions include myopathy, myositis, and arthritis. Nervous system reactions include paralysis, hemiplegia, speech disorders, abnormal gait, meningism, and amnesia. Respiratory system reactions include pneumonia, asthma, respiratory infiltration, and lung disorders. Skin and appendages reactions include urticaria, macropapular rash, and petechiae. Special senses reactions include abnormal vision. Urogenital system reactions include kidney function abnormalities, albuminuria, pyuria, hematuria, and nephrosis.

Persistent nonproductive cough has been reported with all ACE inhibitors, resolving after discontinuation of therapy. Hypotension was reported in 1.2% of patients during clinical trials. Neutropenia and agranulocytosis necessitate periodic monitoring of white blood cell counts in patients with collagen vascular disease and/or renal disease. Additionally, fetal toxicity is a concern, as the use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy can reduce fetal renal function and increase fetal and neonatal morbidity and mortality.

Drug Interactions

Coadministration of quinapril hydrochloride and hydrochlorothiazide with agents that increase serum potassium levels may lead to hyperkalemia. It is advised to monitor serum potassium levels in these patients.

When quinapril hydrochloride and hydrochlorothiazide are used in conjunction with lithium, there is an increased risk of elevated serum lithium levels and potential lithium toxicity. This risk is further heightened due to the renal clearance reduction of lithium caused by thiazides. Therefore, caution is warranted when coadministering these medications, and frequent monitoring of serum lithium levels is recommended.

The dual blockade of the renin-angiotensin system (RAS) with angiotensin receptor blockers, ACE inhibitors, or aliskiren can increase the risks of hypotension, hyperkalemia, and renal function changes, including acute renal failure, compared to monotherapy. Most patients do not experience additional benefits from the combination of two RAS inhibitors. It is generally recommended to avoid the combined use of RAS inhibitors. Patients receiving quinapril hydrochloride and hydrochlorothiazide alongside other RAS-affecting agents should be closely monitored for blood pressure, renal function, and electrolyte levels. Specifically, aliskiren should not be coadministered with quinapril hydrochloride and hydrochlorothiazide in patients with diabetes or renal impairment (GFR <60 ml/min/1.73 m²).

The simultaneous administration of tetracycline with quinapril may reduce the absorption of tetracycline by approximately 28% to 37%, likely due to the high magnesium content in quinapril tablets. This interaction should be considered when coprescribing these medications.

Rare nitritoid reactions, characterized by facial flushing, nausea, vomiting, and hypotension, have been reported in patients receiving injectable gold (sodium aurothiomalate) alongside ACE inhibitors.

In elderly patients, those who are volume-depleted, or individuals with compromised renal function, the coadministration of non-steroidal anti-inflammatory drugs (NSAIDs), including selective COX-2 inhibitors, with ACE inhibitors like quinapril may lead to renal function deterioration, potentially resulting in acute renal failure. These effects are typically reversible, but renal function should be monitored periodically in patients receiving quinapril and NSAID therapy. Additionally, the antihypertensive effect of ACE inhibitors may be diminished by NSAIDs.

Patients on concomitant mTOR inhibitors (e.g., temsirolimus) may face an increased risk of angioedema.

Regarding other agents, multiple doses of propranolol or cimetidine do not affect the pharmacokinetics of single doses of quinapril. The anticoagulant effect of a single dose of warfarin, as measured by prothrombin time, remains unchanged with quinapril coadministration. However, thiazide-induced electrolyte disturbances, such as hypokalemia and hypomagnesemia, can increase the risk of digoxin toxicity, potentially leading to fatal arrhythmic events. No pharmacokinetic interaction was observed when single doses of quinapril and hydrochlorothiazide were administered together.

Thiazide diuretics may interact with several classes of drugs. Alcohol, barbiturates, or narcotics can potentiate orthostatic hypotension. Antidiabetic drugs may require dosage adjustments when used concurrently. The absorption of hydrochlorothiazide is significantly impaired by anionic exchange resins such as cholestyramine and colestipol, with reductions in absorption of up to 85% and 43%, respectively. Corticosteroids and ACTH may intensify electrolyte depletion, particularly hypokalemia. The response to pressor amines (e.g., norepinephrine) may be decreased, although this does not preclude their therapeutic use. Additionally, there may be an increased responsiveness to nondepolarizing skeletal muscle relaxants (e.g., tubocurarine). Finally, the diuretic, natriuretic, and antihypertensive effects of thiazide diuretics may be reduced by concurrent administration of NSAIDs.

Packaging & NDC

The table below lists all NDC Code configurations of Quinapril Hydrochloride and Hydrochlorothiazide, the U.S. brand-name prescription product. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

Pediatric patients, particularly neonates with a history of in utero exposure to quinapril hydrochloride and hydrochlorothiazide, may experience complications such as oliguria or hypotension. In such cases, it is crucial to provide support for blood pressure and renal perfusion. Interventions such as exchange transfusions or dialysis may be necessary to address hypotension and/or to manage impaired renal function. It is important to note that the removal of quinapril from the neonatal circulation, which can cross the placenta, is not significantly accelerated by these interventions.

The safety and effectiveness of quinapril hydrochloride and hydrochlorothiazide in children have not been established, indicating a need for caution when considering this medication in pediatric populations.

Geriatric Use

Clinical studies of quinapril HCl/hydrochlorothiazide did not include a sufficient number of subjects aged 65 and older to determine whether these elderly patients respond differently compared to younger individuals. However, other reported clinical experiences have not identified significant differences in responses between geriatric patients and their younger counterparts.

In general, dose selection for elderly patients should be approached with caution. It is advisable to start at the lower end of the dosing range, taking into account the increased likelihood of decreased hepatic, renal, or cardiac function, as well as the presence of concomitant diseases or other drug therapies. Careful monitoring of these patients is recommended to ensure safety and efficacy.

Pregnancy

Quinapril hydrochloride and hydrochlorothiazide have not been evaluated for carcinogenicity, mutagenicity, or fertility in animal studies. However, quinapril hydrochloride was not found to be carcinogenic in mice or rats at doses up to 75 or 100 mg/kg/day over a 104-week period. Notably, female rats receiving the highest dose exhibited an increased incidence of mesenteric lymph node hemangiomas and skin/subcutaneous lipomas.

In terms of mutagenicity, neither quinapril nor its active metabolite, quinaprilat, demonstrated mutagenic potential in the Ames bacterial assay, both with and without metabolic activation. Additionally, studies in rats indicated no adverse effects on fertility or reproduction at doses up to 100 mg/kg/day.

Hydrochlorothiazide has also shown no genotoxic effects in in vitro assays and did not adversely affect fertility in mice and rats of both sexes when administered doses of up to 100 mg/kg/day and 4 mg/kg/day, respectively, prior to mating and throughout gestation.

Given the lack of comprehensive studies on the effects of quinapril hydrochloride and hydrochlorothiazide during pregnancy, healthcare professionals are advised to weigh the potential benefits against the risks when prescribing these medications to pregnant patients or women of childbearing potential.

Lactation

Quinapril and hydrochlorothiazide are secreted in human milk; therefore, caution should be exercised when administering quinapril hydrochloride and hydrochlorothiazide to lactating mothers. Due to the potential for serious adverse reactions in breastfed infants from hydrochlorothiazide, along with the unknown effects of quinapril in infants, healthcare professionals should consider whether to discontinue nursing or to discontinue the use of quinapril hydrochloride and hydrochlorothiazide. This decision should take into account the importance of the medication to the mother.

Renal Impairment

Quinapril hydrochloride and hydrochlorothiazide should be used with caution in patients with severe renal disease, as thiazides may precipitate azotemia in these individuals, and the effects of repeated dosing may be cumulative. In patients with severe congestive heart failure, where renal function may depend on the renin-angiotensin-aldosterone system, inhibition by quinapril may lead to anticipated changes in renal function, including oliguria, progressive azotemia, and, in rare cases, acute renal failure or death.

Clinical studies have shown that hypertensive patients with unilateral renal artery stenosis treated with ACE inhibitors, including quinapril, experienced increases in blood urea nitrogen and serum creatinine, which were reversible upon discontinuation of the ACE inhibitor, concomitant diuretic, or both. Therefore, renal function should be closely monitored during the first few weeks of therapy in such patients.

Additionally, some hypertensive patients treated with quinapril, even in the absence of preexisting renal vascular diseases, have developed minor and transient increases in blood urea nitrogen and serum creatinine, particularly when quinapril is administered with a diuretic. This occurrence is more likely in patients with pre-existing renal impairment, and dosage reduction of quinapril hydrochloride and hydrochlorothiazide tablets may be necessary. Regular assessment of renal function is recommended for hypertensive patients undergoing treatment.

Hepatic Impairment

Quinapril hydrochloride and hydrochlorothiazide should be used with caution in patients with impaired hepatic function or progressive liver disease. In these patients, even minor alterations in fluid and electrolyte balance may precipitate hepatic coma. The metabolism of quinapril to its active form, quinaprilat, is primarily dependent on hepatic esterases; therefore, patients with compromised liver function may experience markedly elevated plasma levels of quinapril.

Currently, no pharmacokinetic studies have been conducted specifically in hypertensive patients with impaired liver function, which limits the understanding of the drug's behavior in this population. It is essential for healthcare providers to monitor liver function closely in patients receiving this combination therapy.

In cases where patients receiving ACE inhibitors develop jaundice or significant elevations in hepatic enzymes, it is recommended that the ACE inhibitor be discontinued immediately, and appropriate medical follow-up should be initiated to address the patient's condition.

Overdosage

In cases of overdosage with quinapril hydrochloride and hydrochlorothiazide, specific treatment information is limited. Management should focus on symptomatic and supportive care. It is recommended that therapy with quinapril hydrochloride and hydrochlorothiazide be discontinued, and the patient should be closely monitored. Established procedures should be employed to address dehydration, electrolyte imbalances, and hypotension.

The oral median lethal dose of quinapril/hydrochlorothiazide in combination has been observed to range from 1063/664 to 4640/2896 mg/kg in animal studies involving mice and rats. Notably, doses of quinapril between 1440 to 4280 mg/kg have resulted in significant lethality in these species. In single-dose studies of hydrochlorothiazide, most rats survived doses up to 2.75 g/kg.

Human data regarding overdoses of ACE inhibitors, including quinapril, are limited. The most likely manifestation of quinapril overdosage in humans is hypotension. In contrast, overdose with hydrochlorothiazide typically presents with signs and symptoms of dehydration and electrolyte depletion, such as hypokalemia, hypochloremia, and hyponatremia. If digitalis has been administered concurrently, hypokalemia may exacerbate the risk of cardiac arrhythmias.

Laboratory assessments of serum levels of quinapril and its metabolites are not commonly available, and such determinations do not have a defined role in the management of quinapril overdose. Furthermore, there is no evidence to support the use of physiological maneuvers, such as altering urine pH, to enhance the elimination of quinapril and its metabolites. Both hemodialysis and peritoneal dialysis have been shown to have minimal impact on the clearance of quinapril and quinaprilat.

While angiotensin II could theoretically act as a specific antagonist or antidote in the event of quinapril overdose, it is largely unavailable outside of specialized research settings. Given that the hypotensive effects of quinapril result from vasodilation and effective hypovolemia, it is advisable to manage quinapril overdose through the infusion of normal saline solution to restore volume and stabilize blood pressure.

Nonclinical Toxicology

Carcinogenicity, Mutagenicity, Impairment of Fertility

Carcinogenicity, mutagenicity, and fertility studies have not been conducted in animals with quinapril hydrochloride and hydrochlorothiazide. Quinapril hydrochloride was not found to be carcinogenic in mice or rats when administered at doses up to 75 or 100 mg/kg/day for 104 weeks, which corresponds to 50 or 60 times the maximum human daily dose on a mg/kg basis and 3.8 or 10 times the maximum human daily dose on a mg/m² basis. However, female rats receiving the highest dose exhibited an increased incidence of mesenteric lymph node hemangiomas and skin/subcutaneous lipomas. Quinapril and its active metabolite, quinaprilat, were not mutagenic in the Ames bacterial assay, both with and without metabolic activation. Additionally, quinapril was negative in various genetic toxicology studies, including in vitro mammalian cell point mutation, sister chromatid exchange in cultured mammalian cells, micronucleus tests in mice, in vitro chromosome aberration tests with V79 cultured lung cells, and in vivo cytogenetic studies using rat bone marrow. No adverse effects on fertility or reproduction were observed in rats at doses up to 100 mg/kg/day.

Under the auspices of the National Toxicology Program, hydrochlorothiazide was administered in feed to rats and mice for 2 years at doses up to 600 mg/kg/day in mice and up to 100 mg/kg/day in rats. These studies did not reveal evidence of carcinogenic potential in rats or female mice; however, there was equivocal evidence of hepatocarcinogenicity in male mice. Hydrochlorothiazide was not genotoxic in in vitro assays using various strains of Salmonella typhimurium (the Ames test), the Chinese hamster ovary (CHO) test for chromosomal aberrations, or in vivo assays involving mouse germinal cell chromosomes and Chinese hamster bone marrow chromosomes. Positive results were obtained in the in vitro CHO sister chromatid exchange test and in mouse lymphoma cell assays at concentrations ranging from 43 to 1300 mcg/mL. Additionally, positive results were noted in the Aspergillus nidulans nondisjunction assay at an unspecified concentration of hydrochlorothiazide. Hydrochlorothiazide did not adversely affect the fertility of mice and rats of either sex when these species were exposed to doses of up to 100 and 4 mg/kg/day, respectively, prior to mating and throughout gestation.

Postmarketing Experience

During extensive postmarketing experience, the following serious nonfatal adverse events have been reported voluntarily or through surveillance programs, regardless of their relationship to quinapril and HCTZ combination tablets:

In the body as a whole, events such as shock, accidental injury, neoplasm, cellulitis, ascites, generalized edema, hernia, and anaphylactoid reaction have been documented. Cardiovascular system events include bradycardia, cor pulmonale, vasculitis, and deep thrombosis.

For the digestive system, reports include gastrointestinal carcinoma, cholestatic jaundice, hepatitis, esophagitis, vomiting, and diarrhea. Eye disorders noted are acute myopia and acute angle closure glaucoma (refer to WARNINGS).

In the hemic system, anemia has been reported. Metabolic and nutritional disorders include weight loss. Musculoskeletal system events consist of myopathy, myositis, and arthritis.

Nervous system events reported are paralysis, hemiplegia, speech disorder, abnormal gait, meningism, and amnesia. Respiratory system events include pneumonia, asthma, respiratory infiltration, and lung disorder.

Skin and appendages have shown reports of urticaria, macropapular rash, and petechiases. Abnormal vision has been noted in the special senses category. Lastly, urogenital system events include kidney function abnormalities, albuminuria, pyuria, hematuria, and nephrosis.

Patient Counseling

Patients receiving quinapril hydrochloride and hydrochlorothiazide should be advised to immediately report any signs or symptoms of angioedema, such as swelling of the face, eyes, lips, or tongue, or difficulty in breathing. They should temporarily discontinue the medication until they have consulted with their prescribing physician.

Female patients of childbearing age must be informed about the potential consequences of exposure to quinapril hydrochloride and hydrochlorothiazide during pregnancy. Healthcare providers should discuss treatment options with women who are planning to become pregnant and encourage them to report any pregnancies to their physicians as soon as possible.

Patients should be made aware that lightheadedness may occur, particularly during the initial days of therapy, and they should report this to their prescribing physician. If syncope occurs, they should discontinue the medication until they have consulted with their physician.

It is important to inform patients that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to a significant drop in blood pressure due to reduced fluid volume, which may result in lightheadedness and possible syncope.

Patients planning to undergo major surgery or general or spinal anesthesia should be instructed to inform their physicians that they are taking an ACE inhibitor.

Patients receiving quinapril hydrochloride and hydrochlorothiazide should be cautioned against using potassium supplements or salt substitutes containing potassium without first consulting their prescribing physician.

Lastly, patients should be advised to promptly report any signs of infection, such as a sore throat or fever, as these may indicate neutropenia.

Storage and Handling

The product is supplied in tight containers as defined by the United States Pharmacopeia (USP). It should be stored at a temperature range of 20 to 25° C (68 to 77° F), in accordance with USP Controlled Room Temperature guidelines. Proper adherence to these storage conditions is essential to maintain the integrity and efficacy of the product.

Additional Clinical Information

The hydrochlorothiazide component of quinapril hydrochloride and hydrochlorothiazide may lead to a decrease in serum protein-bound iodine (PBI) levels; however, this effect does not indicate any signs of thyroid disturbance. Clinicians should consider interrupting therapy with quinapril hydrochloride and hydrochlorothiazide for several days prior to conducting tests for parathyroid function to ensure accurate results.

FDA Insert (PDF)

This document is the official FDA-approved prescribing information for Quinapril Hydrochloride and Hydrochlorothiazide as submitted by Ranbaxy Pharmaceuticals Inc.. It includes detailed information about indications, dosage, contraindications, warnings, and clinical pharmacology.

View full prescribing information (PDF)