Clinical evaluation of felodipine in patients with refractory hypertension

Felodipine. A review of the pharmacology and therapeutic use of the extended release formulation in older patients

Felodipine is a dihydropyridine calcium antagonist which may be administered once daily in an extended release (ER) formulation. As monotherapy in older patients with mild to moderate essential hypertension, felodipine ER once daily provides effective control of blood pressure (BP). The drug has also been effective, either as monotherapy or in combination with other antihypertensive medications, in comparisons with other antihypertensive agents, and does not adversely affect lipid profiles or, in patients with diabetes mellitus, glycaemic control. Results in patients with angina pectoris and congestive heart failure indicate a potential role for felodipine ER in these indications and data also suggest the drug reduces left ventricular hypertrophy. In addition, felodipine ER appears suitable for use in patients with concomitant respiratory disease, renal or hepatic dysfunction, cerebrovascular or peripheral ischaemic disease, or gout, making it particularly useful in the elderly who often have more than one significant clinical condition. Felodipine ER has generally been well tolerated by older patients in clinical trials, although further confirmation in the long term is desirable. Thus, felodipine ER effectively lowers BP in older patients with essential hypertension with the added convenience of once daily administration. It may be used as monotherapy or in combination with other antihypertensive agents and is a practical advance in the treatment of hypertension in the elderly.

Felodipine. A review of the pharmacology and therapeutic use of the extended release formulation in cardiovascular disorders

Felodipine is a vascular-selective, dihydropyridine calcium antagonist previously investigated as a conventional tablet formulation administered twice daily. More recently considerable experience has been gained with an extended release (ER) formulation which has the convenience of once daily administration. Felodipine ER has been well studied in patients with essential hypertension. As monotherapy in mild to moderate essential hypertension, felodipine ER is at least as effective in reducing blood pressure as other calcium antagonists, beta-blockers, diuretics and ACE inhibitors, with some results favouring felodipine ER at a statistically significant level at the dosages used. It is also effective combined with controlled release metoprolol or enalapril in patients with mild to moderate essential hypertension. In patients with more severe forms of essential hypertension uncontrolled by beta-blocker and/or diuretic therapy, felodipine ER was effective as an 'add-on' therapy in placebo-controlled trials, and, at the dosages used, more effective than either sustained release nifedipine or nitrendipine. Felodipine produces effective control of blood pressure without negative effects on cardiac performance. In addition to its antihypertensive action, results suggest that felodipine therapy is associated with significant regression of left ventricular hypertrophy. Furthermore, it appears suitable for use in patients with concomitant diabetes, renal dysfunction or asthma, and is also being investigated for use in patients with congestive heart failure or angina pectoris. Felodipine ER is an effective drug for the treatment of all grades of essential hypertension, and can be used both as monotherapy and in combination with other antihypertensive agents. Further clinical experience should fully establish the long term tolerability of felodipine ER and consequently its place in therapy relative to other accepted antihypertensive drugs. However, with the convenience of once daily administration, felodipine ER is a worthwhile innovation in the treatment of hypertension.

A trial of the calcium antagonist felodipine in hypertensive type 2 diabetic patients

Although calcium antagonists may impair insulin release in vitro, clinical studies have produced conflicting results. Felodipine is a highly selective dihydropyridine calcium antagonist effective in the treatment of hypertension. The efficacy of felodipine was assessed in a double-blind randomized placebo cross-over study of 21 Type 2 diabetic patients with primary hypertension, 13 men and 8 women, with an age of 61 (range 46-73) years. Thirteen were controlled on oral hypoglycaemic therapy and 8 on diet alone. Mean (SD) blood pressure (mmHg) was 176(20)/102(8) after a 2-4 week placebo run-in period, 169(21)/101(8) during the subsequent placebo period compared with 151(15)/88(9) after 4 weeks felodipine therapy (p less than 0.001). Nineteen patients required 5 mg twice daily and 2 patients 10 mg twice daily to achieve a target diastolic pressure of 95 mmHg. Side-effects seen with felodipine included ankle oedema, facial flushing, headache, and dizziness. During oral glucose tolerance tests performed after the felodipine and placebo phases, mean (SD) fasting blood glucose was 9.5(3.1) and 9.0(3.0) mmol l-1, respectively (NS), and the 90 min (peak) blood glucose was 19.1(4.8) and 18.1(4.8) mmol l-1, respectively (NS). Glycosylated haemoglobin and fructosamine concentrations likewise showed no significant changes.

Pharmacokinetics of felodipine in patients with impaired renal function

1. The pharmacokinetics of felodipine and its effects on blood pressure and heart rate were studied in eight male patients aged between 28 and 57 years with a glomerular filtration rate, GFR, between 8 and 68 ml min-1, following single i.v. and oral administration. 2. Clearance, Cmax, AUC, Vss and V, of felodipine were unaffected by the renal disease. The metabolite excretion (14C-labelled) was slower than in healthy subjects. Initial renal clearance of these metabolites correlated with individual GFR values. The total amount of the dose excreted in the urine was also decreased.