Captopril

Brand Names:  Apo-Capto Capoten Gen-Captopril Novo-Captoril Nu-Capto PMS-Captopril

Drug category: angiotensin-converting enzyme (ACE) inhibitor

Prescription Needed: Yes

What is this drug used for?

Captopril is a medication used to treat high blood pressure congestive heart failure and some kidney diseases (e.g. nephropathy). It is also used to decrease the chances of heart attack or stroke in people who are at high risk (e.g. recent heart attack heart disease or angina).
 
Is there any reason why I shouldn't take this drug?
Do not take this medication if you are allergic to it or similar drugs such as benazepril cilazapril enalapril fosinopril lisinopril moexipril perindopril ramipril quinapril or trandolapril.

Do not take this medication if you are pregnant have experienced a side effect to captopril or captopril-like drugs called angioedema or have a kidney condition called bilateral renal artery stenosis. Tell your doctor specifically if you have or have ever had:

  • Problems with your kidney or liver
  • High levels of potassium in your blood or taking potassium supplements
  • Low levels of sodium in your blood or taking "water pills"
  • Problems with severe dehydration
  • Problems with coughing
  • Low blood pressure (hypotension)
Always disclose your full medical history to the medical team that is taking care of you so that they can provide you with the safest and most effective care.

What about possible side effects?

This medication is usually well tolerated but you should be aware of some potential side effects. The following side effects are more common and can be quite bothersome but unless they are severe you should continue taking captopril as prescribed. Contact your doctor or pharmacist to get advice on how to manage these side effects

  • dry cough
  • low blood pressure
  • dizziness lightheadedness
  • high levels of potassium in the blood
  • feeling tired
  • mild rash hives or itching
  • loss of taste
Less common side effects are:
  • headache
  • fast heart rate
  • flushing
  • mild stomach upset
  • blurred vision
  • muscle and joint pain
  • impotence
These side effects may be related to the dose the use of other medications and other factors (e.g. older age other medical conditions).  As well some of these side effects may go away with time. Talk to your doctor or pharmacist about whether you have any risk factors that may make you more sensitive to these side effects.  Contact your doctor if these symptoms continue or become worse.

Other less common but more serious side effects include:

  • a reaction called angioedema which involves swelling of the face throat tongue lips eyes hands less commonly involving the feet ankles or lower legs - stop taking captopril and call your doctor immediately
  • problems with the kidney - your doctor will assess your risk for this side effect and will monitor you especially when starting treatment with captopril
  • rare cases of hepatitis (inflammation of the liver) and jaundice (yellowing of skin and eyes) have been reported - call your doctor immediately if you experience unexplained nausea vomiting diarrhea stomach pain fatigue loss of appetite dark urine yellowing of the skin and/or eyes
  • fever sore throat chills and other signs of infection - call your doctor immediately
  • severe skin rash difficulty breathing or swallowing hives all over the body or near the face and throat - stop taking captopril and call your doctor immediately
This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as he/she may need to make changes or monitor you more closely:

  • water pills (e.g. hydrochlorothiazide furosemide) - may increase the risk of a low blood pressure reaction or kidney problems
  • allopurinol - may increase your risk of experiencing an allergic reaction to captopril
  • potassium supplements salt substitutes spironolactone amiloride triamterene benazepril cilazapril enalapril fosinopril lisinopril moexipril perindopril ramipril quinapril or trandolapril - increase the chances of having high levels of potassium in the blood
  • terazosin doxazosin prazosin - may increase risk of having low blood pressure reaction
  • other medications to treat high blood pressure - may increase your chances for experiencing low blood pressure
  • gold injections - captopril may increase the risk of side effects from gold injections
  • lithium - can increase the amount of lithium in the blood
  • mercaptopurine - may increase risks of serious side effects related to the blood system
  • trimethoprim - high dose of this drug may increase risks of having high blood levels of potassium
  • ASA/Aspirin & other anti-inflammatories or NSAIDs (e.g. ibuprofen  diclofenac naproxen indomethacin celecoxib diflunisal etodolac flurbiprofen ketoprofen ketorolac mefenamic acid meloxicam nabumetone oxaprozin rofecoxib piroxicam) - can increase the chances of problems with your kidney and may decrease how well captopril works to lower blood pressure and treat congestive heart failure.
  • Avoid herbal products which may increase your blood pressure including ephedra yohimbe and some types of ginseng
  • If you are taking this drug to treat high blood pressure be careful of certain over-the-counter medicines that may increase your blood pressure. These include some cough and cold medicines - if you have questions about specific products ask your pharmacist for more information
  • The following drugs may interfere with how your body processes captopril potentially increasing the risks of side effects - chlorpromazine delavirdine fluoxetine miconazole paroxetine pergolide quinidine quinine ritonavir and ropinirole
This is not a complete list of drug interactions. Ask your doctor or pharmacist to review your list of medications.

Other Information:

Special instructions: Because of the possibility of a sudden drop in blood pressure and dizziness when you first take this drug you may want to take the first dose while sitting or lying down. When you get up do so slowly. To decrease the chances of this happening captopril is usually given in small doses at the beginning of treatment and your doctor will gradually increase your dosage.

If you are dehydrated your blood pressure may become too low when taking captopril. Be careful and make sure you drink enough water to keep you hydrated especially if you have been vomiting or experiencing diarrhea; when exercising; or during exposure to hot weather. Symptoms of dizziness or lightheadedness occur when your blood pressure is too low.

If you are undergoing surgery be sure to let the doctor know that you are taking captopril as it may make you more sensitive to the effects of the anesthetics

Dietary restrictions: Captopril should be taken 1 hour before a meal or 2 hours after - taking captopril with food may decrease the effects.

Lab Tests: Your doctor will likely send you for tests periodically to check the levels of potassium in your blood and your kidney function.

If you test your urine for ketones taking captopril may interfere with your results.

Children: Generally not prescribed however if it is going to be used special dosing is required.

Seniors: Are more sensitive to the side effects so lower doses are usually required especially at the start of therapy.

Pregnant women: The Angiotensin-Converting Enzyme (ACE) Inhibitor class of medications has been associated with serious adverse effects on the fetus in the second and third trimester. Captopril should be discontinued as soon as possible once you find out you are pregnant but you must consult with your doctor about a more appropriate choice of medication to treat your condition.

Women who are nursing: This drug passes into breast milk but the effects on the infant have not been determined. Talk to your doctor.

People who drive or operate machinery should not do so until they know the impact this drug has on them personally. This drug may cause dizziness as a result of lower blood pressure.

Alcohol: While taking captopril avoid the excessive use of alcohol which may increase the risk of low blood pressure dizziness or fainting.

Overdose: A large dose of captopril may cause dizziness and fainting. If you experience any unusual reactions or if you seriously exceed the recommended dosage call your doctor or 911.

Stopping the drug: Talk to your doctor before you stop taking this drug. Stopping the drug will likely cause your blood pressure to increase or your other symptoms due to congestive heart failure to return.

If you miss a dose: Take as soon as you remember. If your next dose is due within 8 hours take a single dose now and skip the next dose then return to your regular dosing schedule. If you are unsure of what to do talk to your doctor or pharmacist. Never take a double dose to make up for a missed dose.

Storage conditions: closed container; cool (below 25C) dry location away from excess moisture (not in the bathroom); direct light always out of reach of children.