1. Clinical Overview
A fixed-dose combination (FDC) of an ACE inhibitor (Ramipril) and an HMG-CoA reductase inhibitor (Atorvastatin). It is primarily indicated for the management of hypertension and dyslipidemia in patients with concomitant cardiovascular risk, particularly for secondary prevention in post-myocardial infarction and post-stroke patients. This combination addresses two major modifiable risk factors for atherosclerotic cardiovascular disease (ASCVD).
| Onset | Duration | Bioavailability |
|---|---|---|
| Ramipril: Antihypertensive effect begins within 1-2 hours, with peak effect at 3-6 hours. Atorvastatin: LDL-C reduction begins within 2 weeks, maximal effect at 4 weeks. | Ramipril: Sustained 24-hour antihypertensive effect with once-daily dosing. Atorvastatin: Requires daily dosing; effect persists for the dosing interval. | Ramipril: Approximately 28-50% (Ramipril) and 45% (active metabolite Ramiprilat). Atorvastatin: ~14% (parent drug) due to extensive first-pass metabolism. |
2. Mechanism of Action
Ramipril inhibits Angiotensin Converting Enzyme (ACE), reducing the conversion of Angiotensin I to the potent vasoconstrictor Angiotensin II, leading to vasodilation, reduced aldosterone secretion (decreasing sodium/water retention), and increased bradykinin levels. Atorvastatin competitively inhibits HMG-CoA reductase, the rate-limiting enzyme in the mevalonate pathway of cholesterol synthesis in the liver, leading to upregulation of LDL receptors and increased clearance of LDL-cholesterol from the bloodstream.
3. Indications & Uses
- Hypertension with concomitant dyslipidemia
- Secondary prevention of cardiovascular events (e.g., post-MI, post-stroke) in patients with hypertension and dyslipidemia
- Management of stable coronary artery disease with hypertension and dyslipidemia
4. Dosage & Administration
Adult Dosage: One tablet (Ramipril 20mg + Atorvastatin 5mg) once daily. Initiation: Preferably start with individual components at lower doses (e.g., Ramipril 2.5mg, Atorvastatin 10mg) and titrate before switching to FDC. The 20mg/5mg strength is a maintenance dose.
Administration: Can be taken with or without food. Preferably taken at the same time each day, in the evening or at bedtime for Atorvastatin (though 24-hour efficacy allows morning dosing). Swallow whole with a glass of water. Do not crush or chew.
5. Side Effects
Common side effects may include:
- Headache
- Dizziness
- Fatigue
- Cough (dry, persistent, due to Ramipril)
- Nausea, constipation, dyspepsia
- Myalgia (muscle pain) - usually mild
- Increased liver enzymes (AST/ALT)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Diuretics (especially loop/thiazide) | Potentiates hypotensive effect; risk of first-dose hypotension. | Major |
| Potassium-sparing diuretics (Spironolactone, Amiloride), Potassium supplements | Increased risk of hyperkalemia. | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | May reduce antihypertensive effect of Ramipril and increase risk of renal impairment. | Major |
| Aliskiren | Increased risk of renal impairment, hyperkalemia, and hypotension. Contraindicated in diabetes/renal impairment. | Major |
| Lithium | Ramipril may increase Lithium levels and toxicity. | Major |
| Potent CYP3A4 inhibitors (Itraconazole, Clarithromycin, HIV protease inhibitors, Cyclosporine, Gemfibrozil) | Markedly increase Atorvastatin levels, significantly raising risk of myopathy/rhabdomyolysis. | Major |
| Warfarin | Atorvastatin may potentiate anticoagulant effect; monitor INR closely. | Moderate |
| Oral Contraceptives | Atorvastatin may increase levels of norethindrone and ethinyl estradiol. | Moderate |
| Digoxin | Ramipril may slightly increase Digoxin levels. | Moderate |
| Colchicine | Increased risk of myopathy, especially in renal impairment. | Major |
7. Patient Counselling
- Do take the medicine at the same time every day as prescribed.
- Do inform all your doctors and dentists you are taking this medicine.
- Do get regular blood tests (lipid profile, kidney function, liver enzymes) as advised.
- Do report any unexplained muscle pain, tenderness, or weakness, especially with fever or dark urine.
- Don't stop taking the medicine without consulting your doctor, even if you feel well.
- Don't take any new medicine, including over-the-counter drugs or herbal supplements, without checking with your doctor/pharmacist.
- Don't consume large amounts of grapefruit juice.
8. Toxicology & Storage
Overdose: Ramipril: Profound hypotension, circulatory shock, bradycardia, electrolyte disturbances (hyperkalemia), renal failure. Atorvastatin: Elevated liver enzymes, possible severe myopathy/rhabdomyolysis.
Storage: Store below 30°C. Protect from light and moisture. Keep in the original blister pack or container. Keep out of reach and sight of children. Do not use after the expiry date printed on the pack.