Ramipril – ACE Inhibitor for High Blood Pressure

What is Ramipril?

Ramipril is a prescription medication belonging to the class of ACE inhibitors (Angiotensin-Converting Enzyme inhibitors). It is one of the most widely used drugs in cardiology and internal medicine. Ramipril is primarily indicated for the treatment of high blood pressure (hypertension), heart failure, and the prevention of cardiovascular events in high-risk patients.

Indications

Ramipril is used in the following conditions:

• Arterial hypertension: Reduction of elevated blood pressure
• Heart failure: Management of cardiac insufficiency following a myocardial infarction
• Diabetic nephropathy: Renal protection in patients with type 2 diabetes and elevated urinary protein excretion
• Cardiovascular prevention: Reduction of the risk of myocardial infarction, stroke, and cardiovascular death in high-risk patients
• Post-myocardial infarction: Improvement of survival rates and reduction of secondary complications

Mechanism of Action

Ramipril is a prodrug that is converted in the liver to its active metabolite ramiprilat after oral administration. Ramiprilat inhibits the angiotensin-converting enzyme (ACE), which normally converts the inactive angiotensin I into the vasoconstricting angiotensin II.

By inhibiting this enzyme, ramipril produces the following effects:

• Reduction of angiotensin II levels in the blood
• Dilation of blood vessels (vasodilation)
• Lowering of blood pressure
• Reduction of cardiac workload (preload and afterload)
• Increase in bradykinin levels, contributing to additional vasodilatory effects

Dosage

The dosage of ramipril depends on the indication, body weight, and renal function of the patient. Typical dosage ranges include:

• Hypertension: 2.5 mg to 10 mg once daily
• Heart failure after myocardial infarction: Starting at 1.25 mg, gradually increased to 10 mg daily
• Renal protection in diabetes: 1.25 mg to 5 mg once daily

Ramipril is generally taken once daily and can be taken with or without food. Dose adjustment is required in patients with impaired renal function.

Side Effects

Like all medications, ramipril can cause side effects. The most common include:

• Dry irritating cough: Affects up to 10% of patients and is caused by increased bradykinin levels
• Dizziness and headache: Especially at the start of therapy due to blood pressure reduction
• Elevated potassium levels (hyperkalaemia): Particularly in patients with kidney disease
• Renal impairment: Especially in patients with pre-existing kidney conditions or volume depletion
• Angioedema: A rare but potentially life-threatening swelling of the face, lips, tongue, or throat

Contraindications

Ramipril must not be used in the following situations:

• Hypersensitivity to ACE inhibitors
• History of angioedema related to previous ACE inhibitor therapy or hereditary angioedema
• Pregnancy (especially from the second trimester onwards) and breastfeeding
• Bilateral renal artery stenosis or stenosis of the artery to a single functioning kidney
• Concomitant use of aliskiren in patients with diabetes or renal impairment

Drug Interactions

Ramipril may interact with various medications and substances:

• Potassium-sparing diuretics and potassium supplements: Increased risk of hyperkalaemia
• Non-steroidal anti-inflammatory drugs (NSAIDs): Reduced antihypertensive effect and increased risk of renal impairment
• Lithium: Possible increase in lithium blood levels
• Antihypertensives and diuretics: Additive blood pressure-lowering effects

References

1. European Medicines Agency (EMA): Ramipril - Summary of Product Characteristics. EMA, 2023. Available at: www.ema.europa.eu
2. Williams B. et al. - 2018 ESC/ESH Guidelines for the management of arterial hypertension. European Heart Journal, 2018; 39(33): 3021-3104.
3. Yusuf S. et al. - Effects of an angiotensin-converting-enzyme inhibitor, ramipril, on cardiovascular events in high-risk patients. The HOPE Study Investigators. New England Journal of Medicine, 2000; 342(3): 145-153.