plendil
| Product dosage: 5mg | |||
|---|---|---|---|
| Package (num) | Per pill | Price | Buy |
| 60 | $0.95 | $57.19 (0%) | 🛒 Add to cart |
| 90 | $0.88 | $85.79 $79.27 (8%) | 🛒 Add to cart |
| 120 | $0.84 | $114.39 $100.34 (12%) | 🛒 Add to cart |
| 180 | $0.80 | $171.58 $143.49 (16%) | 🛒 Add to cart |
| 270 | $0.77 | $257.37 $206.70 (20%) | 🛒 Add to cart |
| 360 | $0.74
Best per pill | $343.16 $267.91 (22%) | 🛒 Add to cart |
Synonyms | |||
Plendil, known generically as felodipine, is a calcium channel blocker medication belonging to the dihydropyridine class, primarily prescribed for the management of hypertension and certain forms of chronic stable angina. It functions by selectively inhibiting the influx of calcium ions into vascular smooth muscle and cardiac muscle, leading to peripheral vasodilation and reduced systemic vascular resistance. Available in extended-release tablet formulations, Plendil provides 24-hour blood pressure control with once-daily dosing, making it a cornerstone in cardiovascular risk reduction strategies. Its significance lies in its ability to lower blood pressure effectively while maintaining a generally favorable side effect profile compared to older antihypertensive agents.
Key Components and Bioavailability of Plendil
Plendil’s active pharmaceutical ingredient is felodipine, formulated in an extended-release matrix system designed to maintain consistent plasma concentrations over 24 hours. The tablet composition includes hypromellose, polyethylene oxide, sodium lauryl sulfate, and other excipients that control the rate of drug release through a combination of diffusion and erosion mechanisms.
The bioavailability of felodipine is approximately 15-20% following oral administration due to significant first-pass metabolism in the gut wall and liver, primarily mediated by cytochrome P450 3A4 (CYP3A4). This extensive metabolism necessitates the extended-release formulation to minimize peak-trough fluctuations and provide smooth antihypertensive effect. Food intake, particularly high-fat meals, can increase felodipine bioavailability by up to two-fold, though clinical significance varies between patients - something we often discuss during medication counseling.
The extended-release properties are crucial not only for maintaining therapeutic blood levels but also for reducing the incidence of side effects commonly associated with immediate-release calcium channel blockers, such as reflex tachycardia and peripheral edema. The specific formulation ensures that peak plasma concentrations occur approximately 2.5-5 hours post-dose, with a terminal elimination half-life of about 11-16 hours.
Mechanism of Action of Plendil: Scientific Substantiation
Plendil exerts its therapeutic effects through selective inhibition of voltage-gated L-type calcium channels in vascular smooth muscle. By blocking the transmembrane influx of calcium ions, felodipine prevents calcium-dependent contraction of vascular smooth muscle, resulting in arterial vasodilation. This mechanism is particularly pronounced in peripheral arterioles, leading to reduced systemic vascular resistance - the primary driver of its antihypertensive effect.
Unlike non-dihydropyridine calcium channel blockers (verapamil, diltiazem), felodipine has minimal direct effects on cardiac conduction and contractility at therapeutic doses, making it particularly suitable for patients with concomitant conduction abnormalities or heart failure with reduced ejection fraction. The vascular selectivity ratio of felodipine is approximately 100:1 for vascular versus cardiac tissue.
The vasodilation occurs predominantly in coronary, cerebral, and renal arteries, which explains its utility in angina management and potential organ-protective effects. From a clinical perspective, I’ve observed that the reduction in afterload can improve myocardial oxygen demand-supply balance in angina patients, while the renal vasodilation may contribute to preserved renal blood flow in hypertensive patients with chronic kidney disease.
Indications for Use: What is Plendil Effective For?
Plendil for Hypertension
Plendil is FDA-approved for the treatment of hypertension, either as monotherapy or in combination with other antihypertensive agents. Clinical trials have demonstrated consistent blood pressure reduction across various patient populations, including elderly patients and those with isolated systolic hypertension. The antihypertensive effect typically begins within 2-5 hours of the first dose, with maximal reduction occurring after 2-4 weeks of continuous therapy.
Plendil for Chronic Stable Angina
For patients with chronic stable angina, Plendil reduces angina frequency and improves exercise tolerance. The mechanism involves both reduced myocardial oxygen demand (through decreased afterload) and improved coronary blood flow (through coronary vasodilation). In practice, I’ve found it particularly useful for patients who cannot tolerate beta-blockers or have concomitant hypertension.
Off-label Applications
While not FDA-approved for these indications, some evidence supports Plendil’s use in Raynaud’s phenomenon and certain forms of pulmonary hypertension. However, these applications require careful individual risk-benefit assessment and close monitoring.
Instructions for Use: Dosage and Course of Administration
The recommended starting dose for hypertension is 2.5-5 mg once daily, with dosage adjustments based on therapeutic response and tolerability. The usual maintenance dose ranges from 5-10 mg daily, though some patients may require up to 20 mg daily. For angina, starting doses are typically 5 mg once daily.
| Indication | Starting Dose | Maintenance Dose | Administration |
|---|---|---|---|
| Hypertension | 2.5-5 mg | 5-10 mg | Once daily, without regard to meals |
| Angina | 5 mg | 5-10 mg | Once daily, consistent timing |
Dosage adjustments are necessary in elderly patients and those with hepatic impairment due to reduced felodipine clearance. Tablets should be swallowed whole and not crushed or chewed, as this would compromise the extended-release properties and potentially lead to excessive peak concentrations.
Therapeutic response for blood pressure control is typically evaluated after 2 weeks, with further adjustments made at 2-4 week intervals. For angina, assessment of exercise tolerance and symptom frequency should occur within the first month of therapy.
Contraindications and Drug Interactions with Plendil
Plendil is contraindicated in patients with known hypersensitivity to felodipine or other dihydropyridines, and those with severe hypotension (systolic BP <90 mmHg). Relative contraindications include acute myocardial infarction, particularly with ongoing ischemia, and unstable angina.
Significant drug interactions occur primarily through CYP3A4 inhibition. Concurrent use with strong CYP3A4 inhibitors can dramatically increase felodipine exposure:
- Macrolide antibiotics (clarithromycin, erythromycin): 2-4 fold increase in AUC
- Antifungals (ketoconazole, itraconazole): Up to 8-fold increase
- Protease inhibitors and some SSRIs: Moderate interaction
Grapefruit juice should be avoided entirely, as it can increase felodipine bioavailability up to threefold through irreversible inhibition of intestinal CYP3A4.
Other important interactions include potentiation of hypotensive effects with other antihypertensives, and potential additive bradycardia when combined with beta-blockers (though less common than with non-dihydropyridine calcium channel blockers).
Clinical Studies and Evidence Base for Plendil
The efficacy and safety of Plendil have been established in numerous randomized controlled trials. The HOT (Hypertension Optimal Treatment) study, while not exclusively evaluating felodipine, provided important evidence supporting aggressive blood pressure control and included many patients on felodipine-based regimens.
The FEVER study demonstrated that felodipine-based therapy reduced cardiovascular events by 27% compared to placebo in hypertensive patients already receiving background therapy. Specifically, stroke risk was reduced by 28%, coronary events by 34%, and all cardiovascular events by 28%.
For angina management, multiple exercise tolerance studies have shown significant improvement in time to onset of angina and ST-segment depression. A meta-analysis of 15 randomized trials found that felodipine increased exercise duration by approximately 60-90 seconds compared to placebo.
Long-term safety data from extension studies indicate maintained efficacy over 2-3 years of continuous treatment, with no evidence of tachyphylaxis. The incidence of peripheral edema, the most common side effect, appears dose-dependent and typically manageable with dose adjustment or combination therapy.
Comparing Plendil with Similar Products and Choosing Quality Medication
When comparing Plendil to other calcium channel blockers, several distinctions emerge. Unlike amlodipine, which has a much longer half-life (30-50 hours), felodipine’s intermediate half-life makes the extended-release formulation particularly important for maintaining 24-hour coverage. In clinical practice, I’ve found some patients who experience edema with amlodipine may tolerate felodipine better, possibly due to differences in vascular selectivity.
Compared to non-dihydropyridine agents, Plendil lacks significant effects on AV nodal conduction, making it preferable for patients with conduction abnormalities or those requiring heart rate control. The side effect profile also differs - felodipine causes more vasodilation-related effects (headache, flushing, edema) but less constipation and bradycardia than verapamil.
Generic felodipine formulations must demonstrate bioequivalence to the reference product, though some patients report variability between manufacturers. When switching between brands, additional monitoring may be warranted during the transition period.
Frequently Asked Questions about Plendil
What is the recommended course of Plendil to achieve results?
Therapeutic blood pressure reduction typically begins within the first few doses, but maximal effect requires 2-4 weeks of continuous therapy. For chronic conditions like hypertension, Plendil is intended for long-term management rather than a finite “course” of treatment.
Can Plendil be combined with beta-blockers?
Yes, Plendil can be safely combined with beta-blockers in most patients, and this combination is often used for enhanced blood pressure control or angina management. However, close monitoring is advised during initiation due to potential additive hypotensive effects.
Is Plendil safe during pregnancy?
Plendil is classified as Pregnancy Category C, meaning risk cannot be ruled out. Use during pregnancy requires careful consideration of potential benefits versus risks, and it’s generally reserved for situations where safer alternatives are unavailable or ineffective.
How should missed doses be handled?
If a dose is missed, it should be taken as soon as remembered unless it’s almost time for the next dose. Doubling up on doses is not recommended due to the risk of excessive hypotension.
Does Plendil cause weight gain?
Unlike some other antihypertensive classes, Plendil is not typically associated with significant weight gain. Peripheral edema may be mistaken for weight gain but represents fluid redistribution rather than true weight increase.
Conclusion: Validity of Plendil Use in Clinical Practice
Plendil remains a valuable therapeutic option in the antihypertensive and antianginal armamentarium, with robust evidence supporting its efficacy and safety profile. The extended-release formulation provides smooth 24-hour blood pressure control, while its vascular selectivity offers advantages in specific patient populations. While newer agents have emerged, Plendil’s established track record, predictable pharmacokinetics, and generally favorable tolerability maintain its relevance in contemporary cardiovascular practice.
I remember when we first started using felodipine extensively in our cardiology practice back in the early 2000s - we were transitioning from older agents and there was some skepticism among the senior consultants about whether these newer dihydropyridines offered any real advantage. Dr. Williamson, our section head at the time, was particularly resistant, having built his career on verapamil and diltiazem. He’d grumble about “flashy new drugs” during our morning case discussions.
But then we had Mrs. Gable, a 72-year-old with hypertension and chronic kidney disease who couldn’t tolerate her beta-blocker due to profound fatigue. Her blood pressure was consistently in the 170s/90s despite maximal doses of her ACE inhibitor. We started her on felodipine 5 mg, and I’ll never forget checking her BP two weeks later - 132/78, and she reported feeling “like myself again.” No significant edema, just mild flushing that resolved within the first week. Dr. Williamson reviewed her chart, muttered something about “beginner’s luck,” but I noticed he started prescribing it more frequently after that.
What surprised me most was discovering that some patients who developed ankle swelling with amlodipine did better with felodipine - counter to what the pharmacology textbooks suggested. We had Mr. Davison, a 58-year-old contractor who needed to be on his feet all day. Amlodipine made his ankles swell so much he couldn’t wear his work boots. Switched to felodipine, same blood pressure control, minimal edema. We never quite figured out why - maybe individual variation in tissue distribution or differences in calcium channel subunit expression.
The learning curve wasn’t without stumbles though. Early on, we had a patient who developed significant hypotension after starting felodipine - turned out he was drinking two glasses of grapefruit juice daily with breakfast. His felodipine levels were likely through the roof. We adjusted the dose and switched him to orange juice, problem solved. Taught us all to be more thorough in our medication counseling.
Now, fifteen years later, I still have patients like Mrs. Gable who’ve been on felodipine all this time with excellent control and no significant side effects. She tells me every visit, “This little pill keeps me going.” That kind of longitudinal success is what ultimately convinced even Dr. Williamson, who eventually admitted over coffee one day that “maybe these new drugs aren’t so bad after all.” Sometimes the evidence in the charts speaks louder than the theoretical concerns.