Captopril – Dose, ROA, MOA, PK, PD, Indications & More

Dose and Dosage:

  • The typical starting dose of captopril for hypertension is 25 mg, taken two or three times daily.
  • The dosage may be titrated based on blood pressure response, usually at intervals of 2 to 4 weeks.
  • The maximum recommended dose is 450 mg per day in divided doses.

Frequency:

  • Captopril is usually taken two or three times daily.

Route of Administration (ROA):

  • Captopril is administered orally in the form of tablets.

Mechanism of Action (MOA):

  • Captopril is an angiotensin-converting enzyme (ACE) inhibitor. It inhibits the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, leading to vasodilation and reduced blood pressure.

Pharmacokinetics (PK):

  • Captopril is rapidly absorbed after oral administration, with peak plasma concentrations reached within 1 to 2 hours.
  • It undergoes extensive metabolism in the liver, primarily by sulfhydryl groups, to form active and inactive metabolites.
  • The elimination half-life of captopril is approximately 2 hours.

Pharmacodynamics (PD):

  • Captopril lowers blood pressure by inhibiting the renin-angiotensin-aldosterone system, leading to decreased peripheral vascular resistance and blood pressure.

Pathophysiology:

  • Hypertension: Captopril is indicated for the treatment of hypertension.
  • Heart Failure: Captopril may also be used in the management of heart failure, either alone or in combination with other medications.

Indications:

  • Hypertension: Captopril is indicated for the treatment of hypertension.
  • Heart Failure: Captopril may be used in the management of heart failure.

Contraindications:

  • Captopril is contraindicated in patients with a history of angioedema associated with previous ACE inhibitor therapy.
  • It should also be avoided in patients with bilateral renal artery stenosis, as it may lead to renal failure.

Drug Interactions:

  • Captopril may interact with other antihypertensive agents, potassium-sparing diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), and lithium.
  • Concurrent use with potassium supplements or potassium-sparing diuretics may increase the risk of hyperkalemia.

Monitoring and Laboratory Tests:

  • Blood Pressure: Monitor blood pressure regularly to assess the effectiveness of captopril therapy.
  • Renal Function: Periodically monitor renal function, especially in patients with pre-existing renal impairment or those receiving concomitant diuretic therapy.

Regular monitoring of blood pressure, renal function, and electrolytes is recommended during captopril therapy to ensure efficacy and safety. Adjustments to the dosage may be necessary based on individual patient response and tolerability.


Why is this medication prescribed?

  • Captopril is prescribed for the treatment of hypertension (high blood pressure) and heart failure. It is an angiotensin-converting enzyme (ACE) inhibitor that helps to relax blood vessels, making it easier for the heart to pump blood throughout the body and lowering blood pressure.

How should this medicine be used?

  • Captopril is usually taken orally, either with or without food.
  • The dosage and frequency of administration will be determined by your doctor based on your medical condition and response to treatment.
  • It is important to take captopril exactly as prescribed by your doctor. Do not change your dose or stop taking the medication without consulting your doctor first.

Other uses for this medicine

  • Captopril may also be used for other conditions as determined by your doctor.

What special precautions should I follow?

  • Before taking captopril, inform your doctor if you have a history of angioedema (swelling of the face, lips, tongue, or throat) associated with previous ACE inhibitor therapy.
  • Inform your doctor about any allergies you may have, especially to ACE inhibitors or other medications.
  • Tell your doctor about any other medications, supplements, or herbal products you are taking, as they may interact with captopril.

What special dietary instructions should I follow?

  • There are no specific dietary restrictions associated with captopril use. However, it is important to maintain a healthy diet low in sodium and saturated fats to help manage hypertension and heart failure.

What should I do if I forget a dose?

  • If you miss a dose of captopril, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

  • Common side effects of captopril may include dizziness, headache, cough, nausea, vomiting, diarrhea, and fatigue.
  • Some people may experience a rash, changes in taste, or an increase in blood potassium levels.
  • Contact your doctor if you experience any severe or persistent side effects while taking captopril.

What should I know about storage and disposal of this medication?

  • Store captopril at room temperature away from moisture and heat.
  • Keep the medication in its original container, tightly closed, and out of reach of children.
  • Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Dispose of any unused or expired medication according to local regulations.

In case of emergency/overdose

  • If you suspect an overdose or experience severe symptoms such as fainting, difficulty breathing, or chest pain, seek emergency medical attention immediately.