RAMIPRIL
Clinical safety rating: avoid
Contraindicated (not allowed)
Ramipril is a prodrug that is hydrolyzed in the liver to its active metabolite ramiprilat, which inhibits angiotensin-converting enzyme (ACE), thereby decreasing angiotensin II production, reducing vasoconstriction, aldosterone secretion, and sodium retention.
| Metabolism | Ramipril is extensively metabolized in the liver (ester hydrolysis) to its active metabolite ramiprilat; further metabolism may involve glucuronidation. |
| Excretion | Primarily renal (60% as unchanged drug and metabolites) and fecal (40% via biliary elimination). |
| Half-life | Terminal half-life of ramiprilat is 13–17 hours (prolonged to 50 hours in renal impairment). Accumulation half-life is 110 hours after multiple doses. |
| Protein binding | Ramipril: ~73% bound to serum proteins; ramiprilat: ~56% bound. |
| Volume of Distribution | Ramipril: ~90 L; ramiprilat: ~500 L (approx 7 L/kg), indicating extensive tissue distribution. |
| Bioavailability | Oral: ~50–60% (ramipril is a prodrug; ramiprilat bioavailability is 28–44%). |
| Onset of Action | Oral: 1–2 hours for peak plasma concentration of ramiprilat; antihypertensive effect begins within 1–2 hours. |
| Duration of Action | 24 hours for blood pressure reduction; hemodynamic effects persist for 24 hours allowing once-daily dosing. |
| Molecular Weight | 416.51 |
Initial: 2.5 mg orally once daily; Maintenance: 2.5-20 mg/day in 1-2 divided doses; Maximum: 20 mg/day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: initial 1.25 mg once daily, max 5 mg/day. GFR 10-30 mL/min: initial 1.25 mg once daily, max 2.5 mg/day. GFR <10 mL/min: not recommended. |
| Liver impairment | Child-Pugh Class A: no adjustment. Child-Pugh Class B: initial 1.25 mg once daily. Child-Pugh Class C: use not recommended due to risk of severe hypotension. |
| Pediatric use | Hypertension: Children ≥6 years: initial 2.5 mg once daily; titrate up to 6.25 mg/m²/day up to 10 mg/day. Not established for other indications. |
| Geriatric use | Initial dose: 1.25 mg once daily; titrate cautiously due to age-related renal impairment and risk of hypotension. |
| 1st trimester | Avoid use; associated with increased risk of congenital malformations, particularly cardiovascular and central nervous system defects, based on human data. |
| 2nd trimester | Contraindicated; risk of fetal renal dysfunction, oligohydramnios, and skull ossification defects. |
| 3rd trimester | Contraindicated; risk of fetal and neonatal hypotension, renal failure, hyperkalemia, and oligohydramnios. |
Clinical note
NSAIDs may diminish the antihypertensive effect Lithium levels may be increased Risk of angioedema can occur at any time discontinue immediately.
| Placental transfer | Ramipril crosses the placenta in humans; detectable in fetal tissues. The active metabolite ramiprilat is also likely transferred. Animal studies demonstrate substantial placental passage. |
| Breastfeeding | Ramipril is excreted into breast milk in low amounts; however, due to the potential for adverse effects on the infant's renin-angiotensin system, especially in preterm infants or those with impaired renal function, caution is advised. Avoid use in breastfeeding mothers if possible; if required, monitor infant for hypotension or renal impairment. |
■ FDA Black Box Warning
USE IN PREGNANCY: Drugs that act directly on the renin-angiotensin system can cause fetal injury and death; discontinue as soon as pregnancy is detected.
| Common Effects | Dry cough Headache Fatigue |
| Serious Effects |
History of angioedema related to previous ACE inhibitor therapyHereditary or idiopathic angioedemaConcomitant use with aliskiren in patients with diabetes mellitus or renal impairment (GFR < 60 mL/min)Pregnancy (especially second and third trimesters)Bilateral renal artery stenosis or stenosis in a solitary kidneySevere hypotension
| Precautions | Angioedema (black patients at higher risk), Hypotension (especially in volume-depleted patients), Renal impairment (monitor serum creatinine), Hyperkalemia (monitor potassium levels), Cough (nonproductive, persistent) |
| Food/Dietary |
Loading safety data…
| Lactation Rating | L3 (Moderately Safe) - limited data suggest low risk but caution recommended. |
| Teratogenic Risk | First trimester: Exposure associated with potential risk of congenital malformations, particularly cardiovascular and central nervous system defects, though absolute risk is low. Second and third trimesters: Contraindicated due to fetal renal dysfunction, oligohydramnios, skull ossification defects, and neonatal hypotension, hyperkalemia, and renal failure. Use is not recommended at any stage of pregnancy. |
| Fetal Monitoring | Maternal: Blood pressure, renal function (serum creatinine, BUN), serum electrolytes (especially potassium), complete blood count, and urinalysis for proteinuria. Fetal: Ultrasound monitoring for oligohydramnios and fetal growth restriction if inadvertent second/third trimester exposure occurs. |
| Fertility Effects | No evidence of adverse effects on fertility in animal studies; human data limited. Theoretical risk of reduced uterine blood flow with chronic use in hypertensive women, but no significant impact on fertility reported. |
| Avoid high-potassium foods (e.g., bananas, oranges, potatoes, tomatoes, spinach) because ramipril increases potassium levels. Use potassium-containing salt substitutes only with medical advice. Alcohol may enhance hypotensive effects. |
| Clinical Pearls | Start at 2.5 mg once daily in patients with heart failure or recent MI; titrate to target dose of 10 mg daily as tolerated. Monitor renal function and electrolytes within 1-2 weeks of initiation or dose increase. Avoid in pregnancy; use two forms of contraception in women of childbearing potential. |
| Patient Advice | Take exactly as prescribed, usually once daily; can be taken with or without food. · Do not use salt substitutes containing potassium without consulting your doctor. · Report any signs of angioedema (swelling of face, lips, tongue, or difficulty breathing) immediately. · Avoid becoming pregnant while on this medication; use effective contraception. · May cause dizziness, especially during the first few days; avoid driving until you know how it affects you. |