Fosinopril sodium (Monopril) is an angiotensin-converting enzyme (ACE) inhibitor. It's used to treat high blood pressure in adults and children. It can also treat heart failure. Fosinopril comes as a tablet that's taken by mouth once daily. Most people don't experience any side effects from fosinopril. But people who did reported cough and dizziness. Though rare, fosinopril and other ACEI inhibitors can cause angioedema, which can be serious. Brand name Monopril has been discontinued; fosinopril is only available as a generic medication.
High blood pressure in people ages 6 years and older
Heart failure (in combination with other medications)
Fosinopril is an angiotensin-converting enzyme (ACE) inhibitor. It relaxes your blood vessels by blocking a protein (called ACE) from squeezing your blood vessels.
Source: DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Less common
Blurred vision
chest pain or discomfort
chills
cold sweats
confusion
dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
fast, slow, or irregular heartbeat
pounding or rapid pulse
sweating
unusual tiredness or weakness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Taken by mouth
Taken once a day
Available as a lower-cost generic
Can cause a cough that might not go away until you stop the medication
Not safe to use if you're pregnant
Might not work as well for lowering high blood pressure in Black adults
Mark your appointments on your calendar to see your healthcare professionals (HCPs) and get any blood work done while you're taking fosinopril. These blood tests help your prescriber check for side effects, like changes in your potassium levels or kidney health. Your dose might need to be adjusted based on your lab results.
You can track how well fosinopril is working for you by checking your blood pressure regularly at home. Write down your blood pressure readings and bring them to your appointments with your provider so you can discuss how well fosinopril is working for you.
Take fosinopril with or without food. If it's hurting your stomach, taking it with food might help.
ACE inhibitors like fosinopril are known to cause a dry cough as a side effect. This can happen at any time during treatment, and might not go away until you stop the medication. Let your prescriber know if you develop a cough that becomes too bothersome.
It's possible to feel dizzy when you start taking fosinopril, and when your prescriber raises your dose. This should get better over time as you continue taking the medication and your body gets used to your new blood pressure. Stand up slowly and carefully from a sitting or lying down position to avoid falling.
Drink enough fluids to stay hydrated while you're taking fosinopril, especially on hot days or after exercising. Your blood pressure might drop too much if you don't have enough fluids in your body. This can worsen dizziness and raise your risk of falls. Ask your prescriber about how to stay hydrated safely if you have heart failure or kidney problems.
Make sure to tell your care team about all the medications you're taking or planning to take. Fosinopril can interact with other medications. These interactions can affect how well your medications work or raise your risk for side effects. Your HCPs and pharmacists can check that your medications are safe to take together.
Don't use nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil), with fosinopril unless your provider says it's okay. Taking these medications with fosinopril can raise your risk for kidney problems.
Make sure to eat a variety of fruits and vegetables, follow a low-salt diet, and get regular exercise while you're taking fosinopril. This helps lower your blood pressure. You might be able to stop taking the medication if your blood pressure is well-controlled with these lifestyle changes.
Stop taking fosinopril and tell your care team right away if you're pregnant. This medication isn't safe to take during pregnancy because it can harm your unborn baby. Your prescriber might recommend a different medication that's safer during pregnancy and lifestyle changes you can make to help lower your blood pressure.
Fosinopril can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Fosinopril, as well as other ACE inhibitors, can cause serious harm to unborn babies. Don't take fosinopril during pregnancy. Before you start fosinopril, discuss with your cardiology team about safer options to lower blood pressure if you're pregnant or thinking of becoming pregnant. If you become pregnant while you're taking fosinopril, stop the medication and let your healthcare team know right away.
Risk factors: Black people | History of angioedema in the past
People who take ACE inhibitors like fosinopril can experience a rare, but serious side effect called angioedema. This involves swelling in different parts of the body, including the face, throat, tongue, and stomach. Swelling of the tongue or throat area can be potentially life-threatening since it can make it difficult to breathe. Angioedema can happen at any time during treatment. You might be more likely to experience angioedema if you're Black, an older adult, or of female sex. Get medical attention immediately if you notice any unusual swelling, stomach pain, or difficulty breathing. You'll have to stop taking fosinopril if this happens.
Some people who received ACE inhibitors, like fosinopril, have experienced serious allergic reactions. They developed certain symptoms, such as trouble breathing, tightness in the throat, nausea, confusion, and anxiety. Get medical help right away if you experience these symptoms.
Risk factors: Kidney problems | Certain autoimmune conditions
People who took captopril, another ACE inhibitor, have developed lower white blood cell (WBC) count after starting treatment. The risk was higher for people who had kidney problems and certain autoimmune conditions, such as lupus. Having lower WBC count can put you at risk for serious infections.
It's unclear whether fosinopril has the same risk for causing lower WBC count. If you have kidney problems, your healthcare team might perform blood draws regularly to check your WBC count. If your levels are too low, your prescriber might ask you to pause fosinopril. Let your healthcare team know if you have symptoms of an infection, such as fever, chills, cough, or tiredness.
Risk factors: Not enough fluid or salt in your body | Taking higher doses of diuretic medications | Taking other medications that can lower blood pressure | Receiving dialysis | Heart failure
Though rare, taking fosinopril can sometimes cause your blood pressure to drop too low. This can make you feel dizzy, tired, or lightheaded. This side effect is more common when you first start fosinopril or when your cardiologist raises your dose. Make sure to stay well-hydrated during treatment. Sit or lie down slowly while holding onto something if you feel dizzy, lightheaded, faint, or tired. And get medical help right away if you accidentally fall and hit your head.
Risk factors: Severe heart failure | Kidney problems or renal artery stenosis | Not enough fluid in your body | Taking other medications that can cause kidney damage
Fosinopril is usually good for the kidneys. But in some cases, it can make kidney problems worse. The risk is higher for people who have certain types of kidney problems, such as renal artery stenosis or kidney damage from severe heart failure. Your cardiology team might order lab tests every so often to make sure your kidneys are healthy and working properly. Tell your care team if you're urinating less often than usual, as this could be a sign that your kidneys aren't working as well.
Risk factors: Diabetes | Kidney problems | Taking other medications that also raise potassium levels
Fosinopril can raise the amount of potassium in your body, which can sometimes be dangerous. Your risk of having high potassium levels is greater if you have diabetes or kidney problems or if you're taking other medications that also raise potassium levels. For this reason, make sure your cardiology team knows your full medical history and what medications you're taking before you start treatment. Get medical help right away if you have symptoms of high potassium levels, such as nausea, muscle weakness, or abnormal heartbeat.
In some rare cases, people who took ACE inhibitors like fosinopril developed serious liver problems. Your healthcare team might order blood tests to check your liver health from time to time. Let your care team know right away if you notice symptoms of liver problems, such as tiredness, stomach pain, or yellowing of your skin.
Adults: The typical starting dose is 10 mg by mouth once per day. If needed, your prescriber will raise your dose over time. The usual dose ranges from 20 mg to 40 mg once per day.
Children (weighing 50 kg or more): The typical dose is 5 mg to 10 mg by mouth once daily.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
History of angioedema
Taking at the same time as aliskiren (Tekturna) for people with high blood sugar
Taking at the same time or within 36 hours of neprilysin inhibitors, such as Entresto (sacubitril / valsartan)
High blood pressure in people ages 6 years and older
Heart failure (in combination with other medications)
High blood pressure
Heart failure
Lower the risk for death after a heart attack
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Aurobindo Pharma Limited. (2024). Fosinopril sodium tablet [package insert]. DailyMed.
Bokhari, M. R., et al. (2023). Renal artery stenosis. StatPearls.
Schoolwerth, A. C., et al. (2001). Renal considerations in angiotensin converting enzyme inhibitor therapy: A Statement for Healthcare Professionals From the Council on the Kidney in Cardiovascular Disease and the Council for High Blood Pressure Research of the American Heart Association. Circulation.
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