Quinapril and Hydrochlorothiazide, Oral Route

A combination treatment for hypertension, quinapril and hydrochlorothiazide works to relax blood vessels and remove excess fluid from the body to allow for increased blood flow.

Overview

Quinapril and hydrochlorothiazide is an oral treatment for hypertension (high blood pressure). Hypertension forces the heart and arteries to work harder to pump oxygen-rich blood around the body, and over time it can cause permanent damage to the heart, brain and kidneys. If left untreated, hypertension can lead to heart failure, stroke or kidney failure and it also increases the risk of heart attack. If blood pressure is controlled with medication and lifestyle changes, the risk of these life-threatening complications can be reduced.

Quinapril is an angiotensin converting enzyme (ACE) inhibitor, which means that it blocks a substance in the body which tightens blood vessels. Hydrochlorothiazide is a diuretic and works to reduce the amount of fluid stored in the body, because excess fluid can constrict blood vessels. When used in combination, quinapril and hydrochlorothiazide can therefore widen blood vessels in order to allow blood to pump more easily around the body. This allows more blood and oxygen to reach the heart and other organs.

Quinapril and hydrochlorothiazide is only available with a doctor’s prescription. It is administered orally in tablet form, and is commonly known under the US brand name Accuretic.

Conditions Treated

  • Hypertension

Type of Medicine

  • ACE inhibitor
  • Diuretic

Side Effects

Quinapril and hydrochlorothiazide can cause some unwanted effects as well as beneficial effects. Some side effects are minor and don’t usually require medical attention, while others should be reported to a medical professional as soon as possible. Familiarize yourself with all side effects in order that you can seek medical care in a timely fashion where appropriate.

The following side effects are less common, but should be reported to a doctor immediately:

  • Cough with mucus
  • Tightness in chest
  • Difficulty breathing
  • Diarrhea

The following side effects are rare but require urgent medical attention:

  • Peeling or blistering skin
  • Wrinkled skin
  • Increased skin sensitivity to sunlight
  • Sunken eyes
  • Sweating
  • Blurred vision
  • Dizziness or lightheadedness when standing up after sitting or lying down
  • Confusion
  • Decreased urine output
  • Dry mouth
  • Increased thirst
  • Sudden increase in heart rate
  • Irregular heartbeat
  • Rapid breathing
  • Pain or cramps in muscles
  • Numb, tingling or painful sensations in hands or feet
  • Trembling
  • Seizures (convulsions)
  • Unusual weakness or tiredness
  • Weak, heavy sensation in legs

The incidence of the following side effects is not known, but if they occur they require urgent medical attention:

  • Shock, signs of which include:
    • Sudden low blood pressure
    • Reduced alertness or awareness
    • Cold, damp skin
    • Weak pulse
    • Hyperventilation
  • Swollen hands, ankles or feet
  • Abnormal bleeding or bruising
  • Speech problems

Quinapril and hydrochlorothiazide commonly causes a headache, a side effect that doesn’t usually require medical attention unless it becomes very severe or prolonged. It’s also normal to experience increased urination, since hydrochlorothiazide is a diuretic. This may be inconvenient but is a natural effect of the medicine. Usually, increased urination occurs within the first four hours of taking the pill, so choose a time to take it when you are usually within easy reach of a bathroom and don’t have to worry too much about being disturbed from your activities.

Less common side effects of quinapril and hydrochlorothiazide, which don’t usually require medical attention unless they become prolonged or severe, include:

  • Back pain
  • Loss or lack of strength
  • Coughing
  • Difficulty sleeping
  • Unusual sleepiness or drowsiness

The following are minor side effects which occur rarely, and should only be reported to a doctor if they become persistent:

  • Mild vision changes or vision impairment
  • Difficulty concentrating
  • Discouragement
  • Loss of interest or pleasure in normal activities
  • Feeling sad or empty
  • Irritability
  • General feelings of illness or discomfort
  • Lack of appetite
  • Constipation

If you notice any other side effects not listed here, contact your doctor as soon as possible. You could also report new side effects to the FDA.

Dosage

The amount of quinapril and hydrochlorothiazide you take will depend on your medical history and the severity of your hypertension. Always follow your doctor’s instructions. Your doctor may increase your dose periodically after determining how well the medicine is working for you.

To start with, adults usually take one tablet once each day. The safety and efficacy of the drug for children has not been established, so if a doctor decides to treat a pediatric patient with this drug they will determine a suitable dose.

Do not crush, chew or break quinapril and hydrochlorothiazide tablets. Swallow them whole with water if necessary.

This medicine can be taken either with or without food and at any time of day, though it is recommended that you take it at the same time each day. Since hydrochlorothiazide is a diuretic and increases urine output, you may benefit from taking it at least four hours before bedtime so that you are not disturbed in the night to go to the bathroom.

If you miss a dose of quinapril and hydrochlorothiazide, take it as soon as you remember. However, if it is almost time for the next dose when you remember that you have missed a dose, simply skip the missed dose and continue with your normal dosing schedule. Do not double doses of quinapril and hydrochlorothiazide to make up for a missed dose, as doing so could increase the risk of severe side effects.

Interactions

It is not recommended to take any of the following medicines with quinapril and hydrochlorothiazide. If you already take these drugs, your doctor will either choose not to prescribe quinapril and hydrochlorothiazide, or they will change the other medicines that you are taking.

  • Aliskiren (Tekturna)
  • Dofetilide (Tikosyn)
  • Sacubitril (Entresto)

Other drugs that may interact with quinapril and hydrochlorothiazide include:

  • Gold injections (Myocrisin)
  • Immune system suppressants
  • Medicines which increase blood potassium levels (such as losartan, valsartan and birth control pills which contain drospirenone)

Quinapril and hydrochlorothiazide contains magnesium, which can affect the body’s ability to absorb some drugs. If you take medicines which will be affected by quinapril and hydrochlorothiazide in this way, your doctor may instruct you to take existing medicines at certain times of day so that they do not interact. Examples of drugs which may be less effective when taking with quinapril and hydrochlorothiazide include:

  • Quinolone antibiotics (such as levofloxacin and ciprofloxacin)
  • Tetracycline antibiotics (such as minocycline and doxycycline)
  • Thyroid medicines (such as levothyroxine)
  • Bisphosphonates for osteoporosis (such as alendronate)

Some medicines can increase blood pressure and shouldn’t be prescribed to patients with hypertension. Examples of this are:

  • Cough, cold and flu medicines
  • Diet aids
  • NSAIDs (such as ibuprofen or naproxen)

Many of these medicines can be purchased over the counter (OTC). It is vital that you check with your doctor or a pharmacist whether it is safe to use an OTC medicine before taking it.

If quinapril and hydrochlorothiazide is taken at the same time as bee or wasp sting allergy desensitization injections, a very serious reaction could occur.

Certain lab tests, particularly tests for parathyroid function, can be interfered with and lead to false positives when quinapril and hydrochlorothiazide is taken at the same time. Ensure lab personnel and doctors know that you are taking this medicine.

If you visit multiple different doctors, it’s important that each one knows exactly what medicines you are taking to avoid causing harmful interactions. It may be helpful to write down a list of all medicines (including prescription and OTC), herbal supplements and multivitamins you are taking and any other treatments you are undergoing. You can then present this to each doctor or healthcare professional you have an appointment with. This list may also be helpful to doctors and paramedics if you are admitted to hospital in an emergency.

Warnings

Increased risk of angioedema

Patients with a history of angioedema, which is swelling of the face, lips, tongue, throat, arms or legs, may be at an increased risk of the condition occurring again while taking quinapril and hydrochlorothiazide. Make sure your doctor knows about this condition before you start taking the drug.

Sometimes quinapril and hydrochlorothiazide can cause intestinal angioedema which is a very serious condition. If you have symptoms of intestinal angioedema seek medical attention straight away. Signs of the condition include:

  • Severe stomach pain
  • Nausea
  • Vomiting

Conditions which make quinapril and hydrochlorothiazide an unsuitable treatment

Quinapril and hydrochlorothiazide should not be prescribed to patients with the following conditions:

  • Anuria (inability to pass urine)
  • Diabetes or kidney problems when also taking aliskiren (Tekturna)
  • Sulfa drug allergy (examples of sulfa drugs include sulfamethoxazole, Bactrim and Septra)

The drug could also cause potassium levels to become too high in patients with diabetes or kidney disease.

In patients with congestive heart failure, this drug could cause kidney problems.

Risk of blood problems

Patients with the autoimmune disease collagen vascular disease, or kidney disease, may not be able to take quinapril and hydrochlorothiazide. The drug can pose a risk of blood problems in these patients. Your doctor may not prescribe quinapril and hydrochlorothiazide, or they may monitor you more closely.

Risk of worsening conditions

Quinapril and hydrochlorothiazide may cause the following medical conditions to worsen and should therefore be used with caution:

  • Electrolyte imbalance, such as:
    • High or low calcium levels
    • High or low magnesium levels
    • High or low potassium levels
    • High blood sodium levels
  • Fluid imbalance, caused by:
    • Excessive perspiration
    • Vomiting
    • Diarrhea
  • Glaucoma (secondary angle closure)
  • Gout
  • Heart disease
  • Blood vessel disease
  • Hypercholesterolemia (high cholesterol levels)
  • Hypertriglyceridemia (high triglyceride or fat levels in blood)
  • Kidney disease
  • Liver disease
  • Acute myopia (eyeball changes which cause vision problems)
  • Systemic lupus erythematosus (SLE)

Management of hypertension

Quinapril and hydrochlorothiazide and other treatments for hypertension are only tools for managing the condition and they do not permanently cure it. They will reduce your blood pressure only for as long as you are taking the medicine, so do not stop taking it once your blood pressure reaches a normal level unless directed to do so by your doctor.

The best way to treat hypertension is to make lifestyle changes, and your doctor may instruct you to do this at the same time as prescribing quinapril and hydrochlorothiazide. Common lifestyle changes include:

  • Losing weight
  • Consuming less sodium
  • Consuming less cholesterol
  • Doing more exercise
  • Quitting smoking

You may be referred to a nutritionist to help you make safe, healthy changes to your diet. If you plan to adopt a new exercise regime, check first with your doctor that it is safe to do so. Your health conditions may limit the amount of exercise you can do. It is safer to gradually build up the amount of exercise you do over a period of weeks or months.

Fluid intake

Your doctor will likely recommend that you drink plenty of fluids while taking quinapril and hydrochlorothiazide tablets. This is because the medicine increases urine output in order to remove excess fluid from the body. If you do not drink adequate fluids, you risk becoming dehydrated which can cause serious health problems.

Dizziness

Sometimes quinapril and hydrochlorothiazide can cause dizziness, lightheadedness or fainting. This is most common when getting up quickly from a sitting or lying position. You should avoid driving or operating machinery when you first start taking quinapril and hydrochlorothiazide until you know how the drug affects you.

If you become dizzy, lie down for a few moments to avoid fainting. Once the dizziness has passed, slowly sit up and remain seated for a few minutes to prevent the dizziness from returning.

Vomiting or diarrhea

If you become sick while taking quinapril and hydrochlorothiazide and it causes you to have severe vomiting or diarrhea, call your doctor. You may have to stop taking the drug for a short period to avoid losing too much fluid, which can be extremely dangerous.

Similarly, if you are in a situation in which you sweat a great deal, make sure you drink plenty of water to make up for the fluid lost.

Pregnancy and breastfeeding

Quinapril and hydrochlorothiazide is an FDA pregnancy category D drug, which means it is not recommended for use during pregnancy. Studies in pregnant women have demonstrated a risk to the fetus. The drug could cause fetal deformity or fetal or neonatal (newborn) hypotension (low blood pressure), skull hypoplasia, renal failure or death. The risk of these conditions is highest if the drug is taken during the second or third trimesters.

However, if it is a life-threatening situation and the benefits of the drug far outweigh potential risks to the fetus, the drug may still be prescribed. It is vital that you tell your doctor immediately if you become pregnant while taking quinapril and hydrochlorothiazide.

Quinapril and hydrochlorothiazide is excreted in human breast milk, but it is not known what effects the drug may have on nursing infants. Depending on the value of the drug to the mother, either the drug or breastfeeding should be discontinued to avoid risking the health of the nursing infant.

Elderly patients

Quinapril and hydrochlorothiazide can be just as effective in treating hypotension in elderly patients as it is in younger adults. However, elderly patients are more likely to have heart, liver or kidney problems as a result of their age. Doctors may therefore by more cautious in prescribing this drug to elderly patients, and may request additional tests before deciding whether it is an appropriate treatment. They may prescribe lower doses of the medicine to minimize the risk of harmful side effects, and they may monitor the patient more closely than usual.

Tobacco and alcohol use

While tobacco and alcohol may not interact directly with quinapril and hydrochlorothiazide, both of these substances can contribute to hypotension. For this reason, your doctor may recommend that you cut down or quit completely your use of tobacco and alcohol. Ask your doctor for help if you think you may struggle to stop using tobacco or drinking alcohol.

Storage

Store quinapril and hydrochlorothiazide in the container it is provided in with the cap tightly closed. You should keep the medicine from freezing and keep it away from moisture, heat and direct light. It is not recommended to store this drug in the bathroom.

Keep quinapril and hydrochlorothiazide away from children and pets by storing it up and away from the ground. Do not share the medicine with anyone else, as doing so could be extremely harmful.

If you have leftover unused or expired medicine, ask your healthcare provider how to dispose of it correctly. There may be a local medicine take-back program you can use. Do not flush the medicine down the toilet or pour it down the drain.

Summary

Quinapril and hydrochlorothiazide is a combination oral treatment for hypertension. Quinapril is an ACE inhibitor which works to relax blood vessels throughout the body. Hydrochlorothiazide is a diuretic which increases urine output in order to reduce salt and fluid levels throughout the body. Together, the drugs help to increase blood flow in order so that the heart and other organs receive more oxygen-rich blood.

This medicine helps to manage high blood pressure, but it is not a permanent cure. It is designed for long term use and shouldn’t be stopped if blood pressure reaches a normal level, because doing so will simply cause blood pressure to rise again. Doctors often advise patients to make lifestyle changes, such as losing weight, adjusting their diet and quitting smoking, to help permanently reduce blood pressure. Medicines like quinapril and hydrochlorothiazide simply help to manage hypertension while the patient strives to improve their overall health.

Since quinapril and hydrochlorothiazide contains a diuretic, it will naturally cause patients to urinate more frequently. Usually the increased urine output occurs within the first four to six hours of taking the medicine. Patients should therefore choose an appropriate time to take their daily dose when they will not mind being disturbed by frequent trips to the bathroom. For example, they may want to avoid taking it too close to bedtime so that their sleep is not disturbed.

It’s also common for quinapril and hydrochlorothiazide to cause headaches. This effect does not usually require medical attention unless headaches become very severe and prolonged. The headaches may dissipate as the body adjusts to the drug. Other minor side effects include back pain, sleep problems, mild mood changes and lack of appetite.

If you experience a cough (with mucus), chest tightness, breathing problems, diarrhea, decreased urine output or irregular heartbeat while taking quinapril and hydrochlorothiazide, seek urgent medical attention.

Quinapril and hydrochlorothiazide should not be taken at the same time as aliskiren, dofetilide or sacubitril. The drug can also interact with many other medicines, so make sure your doctor knows about all the prescribed and OTC medicines you take, as well as herbal supplements or multivitamins you consume.

If you become ill while taking quinapril and hydrochlorothiazide and experience diarrhea or vomiting, contact your doctor immediately. The drug naturally reduces fluids in the body, and diarrhea and vomiting also cause fluid loss. Dehydration could therefore occur.

Quinapril and hydrochlorothiazide is not suitable for use during pregnancy due to serious risks to the fetus. Tell your doctor if you become pregnant while taking this drug.

 

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Last Reviewed:
January 31, 2018
Last Updated:
January 27, 2018