Effect of felodipine on indomethacin-induced gastric ulcers in rats

Felodipine is a calcium channel blocker with antioxidant and anti-inflammatory properties. Researchers have stated that oxidative stress and inflammation also play a role in the pathophysiology of gastric ulcers caused by nonsteroidal anti-inflammatory drugs. The aim of this study was to investigate the antiulcer effect of felodipine on indomethacin-induced gastric ulcers in Wistar rats and compare it with that of famotidine. The antiulcer activities of felodipine (5 mg/kg) and famotidine were investigated biochemically and macroscopically in animals treated with felodipine (5 mg/kg) and famotidine in combination with indomethacin. The results were compared with those of the healthy control group and the group administered indomethacin alone. It was observed that felodipine suppressed the indomethacin-induced malondialdehyde increase (P<0.001); reduced the decrease in total glutathione amount (P<0.001), reduced the decrease superoxide dismutase (P<0.001), and catalase activities (P<0.001); and significantly inhibited ulcers (P<0.001) at the tested dose compared with indomethacin alone. Felodipine at a dose of 5 mg/kg reduced the indomethacin-induced decrease in cyclooxygenase-1 activity (P<0.001) but did not cause a significant reduction in the decrease in cyclooxygenase-2 activity. The antiulcer efficacy of felodipine was demonstrated in this experimental model. These data suggest that felodipine may be useful in the treatment of nonsteroidal anti-inflammatory drug-induced gastric injury.

L-Type Ca2+ Channel Inhibition Rescues the LPS-Induced Neuroinflammatory Response and Impairments in Spatial Memory and Dendritic Spine Formation

Ca2+ signaling is implicated in the transition between microglial surveillance and activation. Several L-type Ca2+ channel blockers (CCBs) have been shown to ameliorate neuroinflammation by modulating microglial activity. In this study, we examined the effects of the L-type CCB felodipine on LPS-mediated proinflammatory responses. We found that felodipine treatment significantly diminished LPS-evoked proinflammatory cytokine levels in BV2 microglial cells in an L-type Ca2+ channel-dependent manner. In addition, felodipine leads to the inhibition of TLR4/AKT/STAT3 signaling in BV2 microglial cells. We further examined the effects of felodipine on LPS-stimulated neuroinflammation in vivo and found that daily administration (3 or 7 days, i.p.) significantly reduced LPS-mediated gliosis and COX-2 and IL-1β levels in C57BL/6 (wild-type) mice. Moreover, felodipine administration significantly reduced chronic neuroinflammation-induced spatial memory impairment, dendritic spine number, and microgliosis in C57BL/6 mice. Taken together, our results suggest that the L-type CCB felodipine could be repurposed for the treatment of neuroinflammation/cognitive function-associated diseases.

Severity of coeliac disease and clinical management study when using a CYP3A4 metabolised medication: a phase I pharmacokinetic study

OBJECTIVE

Severity of coeliac disease depends in part on the extent of small intestinal mucosa injury. Patients with the most abnormal pathology have loss of duodenal villi CYP3A4, a drug-metabolising enzyme that inactivates many drugs. These patients are hypothesised to have greater systemic concentrations of felodipine, a drug which normally has low oral bioavailability secondary to intestinal CYP3A4-mediated metabolism. It serves as a representative for a class containing many medications.

DESIGN

A phase I, open-label, single-dose, pharmacokinetic study.

SETTING

London, Ontario, Canada.

PARTICIPANTS

Patients with coeliac disease (n=47) with positive serology and healthy individuals (n=68).

MAIN OUTCOME MEASURES

Patients with coeliac disease-upper gastrointestinal endoscopy and oral felodipine pharmacokinetics study within a 3-week period. Healthy individuals-oral felodipine pharmacokinetics study with water and grapefruit juice.

RESULTS

Coeliac stratification categories: Group A (n=15, normal), B+C (n=16, intraepithelial lymphocytosis with/without mild villous blunting) and D (n=16, moderate/severe villous blunting). Groups A, B+C and D had linear trends of increasing felodipine AUC_0-8; mean±SEM, 14.4±2.1, 17.6±2.8, 25.7±5.0; p<0.05) and Cmax (3.5±0.5, 4.0±0.6, 6.4±1.1; p<0.02), respectively. Healthy subjects receiving water had lower felodipine AUC_0-8 (11.9±0.9 vs 26.9±0.9, p=0.0001) and Cmax (2.9±0.2 vs 7.7±0.2, p=0.0001) relative to those receiving grapefruit juice.

CONCLUSIONS

Increased felodipine concentrations in patients with coeliac disease were most probably secondary to decreased small intestinal CYP3A4 expression. Patients with severe coeliac disease and healthy individuals with grapefruit juice had equivalently enhanced effect. Thus, patients with severe coeliac disease would probably experience similarly altered drug response, including overdose toxicity, from many important medications known to be metabolised by CYP3A4. Patients with coeliac disease with severe disease should be considered for other clinical drug management, particularly when there is the potential for serious drug toxicity.

Calcium Antagonists Use and Its Association with Lower Urinary Tract Symptoms: A Cross-Sectional Study

Background

Lower urinary tract symptoms (LUTS) have been reported amongst the side effects of calcium antagonists (CA). CAs act on the bladder by affecting the ability of the detrusor muscle to create enough contractile force to overcome obstruction to normal voiding. We aimed to determine the relationship between CA use and LUTS in general medical inpatients.

Methods and Findings

In this cross-sectional study we recruited 278 medical inpatients (including 85 CA users) aged ≥40 (72.1±13.7) years. LUTS was assessed using the International Prostate Symptoms Score (IPSS) questionnaire. A Logistic regression model using a ‘backwards-elimination’ strategy was used to identify variables associated with LUTS and for calculating the adjusted odds ratios and the 95% confidence intervals (CI). After adjusting for other risk factors and drugs, patients on amlodipine/nifedipine and diltiazem/verapamil (compared to non-users) were more likely to suffer from severe LUTS [Males: 12.45(CI: 1.57–98.63) and Females: 7.75(CI: 0.94–63.94)] and moderate-to-severe LUTS [Males: 17.43(CI: 2·26–134.39) and Females: 47.8(CI: 6.22–367.37)]. Patients on felodipine/lercanidipine were less likely to suffer from either severe or moderate-to-severe LUTS. Further, 19 (22.4%) CA-users were on treatment for LUTS compared to 18 (9.3%) of the non-users group, p = 0.003. Both male and female CA-users were three times more likely to be on alpha-blockers than non-users, p<0.001. CA-users were more likely to have undergone urinary tract-related surgery (Males: two times, p = 0.07 and females: nine times, p = 0.029). The study was limited by the fact that a causal relationship could not be established between CA use and LUTS.

Conclusions

Our results demonstrate an association between CA use and an increasing severity of LUTS. They also demonstrate that CA-users are more likely to have medical or surgical treatment for LUTS. However, these CA’s effects on LUTS vary, and the use of highly vascular selective agents does not appear to pose significant risk.

[Comparative eficacy of antihypertensive therapy in patients with arterial hypertension and various sensitivity to salt]

In 102 patients with high risk (52 patients with history of myocardial infarction, 50 patients with history of cerebral stroke within previous 6-48 months) arterial hypertension (AH) we studied clinical efficacy on angiotensin converting enzyme inhibitor (ACEI) lisinopril, calcium antagonist felodipine, and nonselective - -blocker carvedilol in dependence on salt sensitivity of AH. Efficacy of treatment was assessed with the help of office pressure measurement and 24 hour arterial pressure monitoring before and after 12 weeks of therapy. Patients who showed 10 or more mm Hg lowering of AP at transition from high salt (15 g/day) to low salt ( 3 g/day) diet were considered salt sensitive. On the basis of obtained results optimal for the treatment of AH in salt resistant patients are ACEI while in the treatment of salt sensitive patients it is expedient to administer calcium antagonists. The use of -adrenoblockers is equally effective in AH with various salt sensitivity.

[Efficacy, safety and tolerance of Felodipine controlled release tablets and Felodipine controlled release tablets associated combination therapy in the treatment of mild to moderate essential hypertension in China]

OBJECTIVE

To evaluate the efficacy, safety and tolerance of Felodipine controlled release tablets and Felodipine controlled release tablets associated combination each with Metoprolol, Lisinopril or Hydrochlorothiazide in the 12 weeks treatment of mild to moderate essential hypertension in China.

METHODS

Multicenter, random samples, and open study have been processed.

RESULTS

(1)After 12 weeks associated combination treatment of anti-hypertension, the percentages of the persons who had attained the target were 80.2% of ITT group in Felodipine controlled release tablets associated combination with Hydrochlorothiazide, 74.1% of ITT group in with Metoprolol,and 80.5% of ITT group in with Lisinopril, respectively. (2)Mean reductions of systolic/diastolic blood pressure from baseline were 16.8/10.6 mm Hg in combination with Hydrochlorothiazide, 16.6/10.7 mm Hg in combination with Metoprolol,and 18.0/12.8 mm Hg in combination with Lisinopril each. There was no significant difference among these three groups (P>0.05). With the Felodipine controlled release tablets treatment alone, the mean reductions from baseline was 24.8/17.5 mm Hg. But in combination with Lisinopril, the blood pressure could lower more quickly, and then could reach the target more rapidly. (3)In the ITT group, the drug compliance with Felodipine controlled release tablets was 97.7%, with those in combination with Hydrochlorothiazide 89.8%, with those in combination with Metoprolol 100.0%, and with those in combination with Lisinopril 96.4%. The main adverse event related to Felodipine was headache, and to Lisinopril was cough.

CONCLUSION

Antihypertensive drug Felodipine controlled release tablets are good and effective. And Felodipine controlled release tablet associated combination each with Metoprolol, Lisinopril or Hydrochlorothiazide can make most patients reach the treatment target, with safety, good tolerance, and high compliance.

Different roles of pummelo furanocoumarin and cytochrome P450 3A5*3 polymorphism in the fate and action of felodipine

OBJECTIVE

Herein we aim to test if pummelo furanocoumarins can inhibit cytochrome P450 (CYP) 3A both in vitro and in vivo, and to explore the influence of CYP3A5*3 (GenBank AC005020: A22893-->G) polymorphism in the pharmacokinetics and pharmacological response to felodipine.

METHOD

Fruit juices of pummelo grapefruit (Citrus paradisi Macf., G), 'Guanximiyou' (C. grandis Osbeck vs. Guanxi, P) and 'Changshanhuyou' (C. changshanhuyou Y.B. Chang, H) were selected by screening Citrus fruit juices for their furanocoumarin contents and their inhibition of testosterone 6beta-hydroxylation in human liver microsomes. Twelve healthy male Chinese were administered 250 mL G, P, H or water (W) alternatively with 26-mumol (10-mg) plain tablet felodipine, and were observed for 12 h.

RESULTS

G had more furanocoumarins and at higher levels than P while H had none, and their potencies for in vitro CYP3A inhibition were in the order as G > P > H. The geometric mean and 90% confidence intervals of pharmacokinetic parameters for human oral felodipine with G, P, H and W were respectively as follows: peak plasma concentration (nmol.L(-1)), 37 (32-44), 25 (21-29), 19 (16-22) and 18 (15-21); area under the plasma concentration-time curve (nmol.h.L(-1)), 118 (103-136), 84 (73-97), 64 (56-74) and 59 (51-68). Subjects showed higher heart rates with G than with H or W. CYP3A5*3 polymorphism showed no significant effect on felodipine pharmacokinetics and related hemodynamic changes.

CONCLUSIONS

This work supports the hypothesis that CYP3A inhibition by furanocoumarins caused pummelo fruit juice-drug interaction; while the role of CYP3A5 in the population pharmacokinetics of felodipine and blood pressure response appear to be limited.

Felodipine-influenced gingival enlargement in an uncontrolled type 2 diabetic patient

BACKGROUND

The potential of calcium channel blockers (CCBs) to induce gingival enlargement (GE) as well as the influence of diabetes mellitus on periodontal tissues has been well documented. This case report documents a conservative clinical approach to the management of felodipine-influenced gingival enlargement and displays a clinical and histologic case of felodipine-influenced GE in an undiagnosed type 2 diabetic patient.

METHODS

At the initial examination, a medical consultation was requested and two incisional biopsies were taken for pathological evaluation. The patient was diagnosed with uncontrolled type 2 diabetes. Felodipine was withdrawn and the diabetes was controlled before dental treatment was initiated. The patient then underwent selective extractions and full-mouth scaling and root planing as well as oral hygiene instructions. No surgical therapy was indicated.

RESULTS

The histological results demonstrated the presence of elongated rete pegs; fibrous hyperplasia; a low-grade chronic inflammatory infiltrate, predominantly consisting of lymphocytes; and collagen bundle groups randomly distributed. These features were similar to those present in other drug-influenced GE. Clinical results have demonstrated almost complete resolution of GE after the withdrawal of felodipine and the control of diabetes. Further improvements were seen after scaling and root planing and oral hygiene instructions. No recurrences were noted 12 months after initial therapy.

CONCLUSIONS

This report demonstrated that the control of systemic factors seemed to have the most influence on success for this particular case. Since the control of diabetes was managed at the same time as the felodipine withdrawal, it remains difficult to speculate how these two factors impacted both the severity of the GE and the therapeutic results. More importantly, the conservative treatment rendered demonstrated the stability of periodontal status during maintenance phase and the avoidance of surgical interventions.

Drug-associated gingival enlargement: case report and review of aetiology, management and evidence-based outcomes of treatment

"Gingival enlargement" is the term now used to describe medication-related gingival overgrowth or gingival hyperplasia (AAP, 2004), a condition commonly induced by three main classes of drugs: anticonvulsants, antihypertensive calcium antagonists and the immunosuppressant cyclosporin. It is important that the health practitioner is aware of the potential aetiologic agents and characteristic features in order to be able to accurately diagnose and successfully manage patients who present with a condition such as outlined in the following case presentation.

Evaluation of a therapeutic conversion from amlodipine to felodipine

STUDY OBJECTIVES

To determine patient satisfaction with and tolerability of a conversion from a long-acting calcium channel blocker, amlodipine, to felodipine. Secondary objectives were to compare the effect of the change on blood pressure and heart rate and the economic impact of the change.

DESIGN

Retrospective study.

SETTING

Veterans Affairs health care system.

PATIENTS

Two hundred eighty-three men who were taking amlodipine to manage hypertension.

INTERVENTION

Patients who were converted to felodipine were mailed a survey quantifying subjective symptoms; the survey also included questions specific to the change program. Transitory blood pressure and heart rate measurements retrieved by electronic chart review were evaluated during therapy with both amlodipine and felodipine.

MEASUREMENTS AND MAIN RESULTS

Ninety-five percent of patients were satisfied with the conversion process and tolerated the switch from amlodipine to felodipine. Mean systolic and diastolic blood pressures were reduced by 4.4 and 2.6 mm Hg, respectively (p=0.166 and 0.187, respectively). Heart rate was reduced significantly by 4.2 beats/minute (p=0.008). The conversion realized a net annual drug cost savings of approximately dollars 16,000.

CONCLUSION

Our patient population was satisfied with the conversion from amlodipine to felodipine, and the new drug was found to be effective, well tolerated, and associated with a modest cost reduction.

Safety and Efficacy of Therapeutically Equivalent Doses of Sustained-Release Formulations of Isradipine and Felodipine

This open-label, drug substitution study was conducted to determine if subjects receiving sustained-release isradipine (SR-I) can be safely switched to sustained-release felodipine (SR-F) and to assess whether SR-I provides better 24-hour blood pressure (BP) control than SR-F. Forty-one men receiving either SR-F 5 mg or SR-F 10 mg once daily for at least 6 months were switched to an equivalent dose of SR-I; BP was measured 2, 4, and 6 weeks after substitution. Significant reductions in systolic BP were seen in the SR-I 10 mg group after 4 weeks and they remained significantly lower through 6 weeks (p< or =0.05). Diastolic BP was reduced, but not significantly. After 6 weeks, SR-F therapy was reinstated, and BP returned toward baseline values. No serious adverse events were reported. SR-I can be safely substituted for SR-F and may provide better 24-hour control of BP than SR-F.

Pharmacodynamic Interactions of Levosimendan and Felodipine in Patients with Coronary Heart Disease

OBJECTIVE

The aim was to study the pharmacodynamic interactions and safety of the co-administration of the calcium sensitizer levosimendan and the calcium antagonist felodipine in patients with coronary heart disease (CHD) and with normal ejection fraction (EF).

METHODS

The study was a randomized, double blind, placebo-controlled, crossover study in 24 male patients with Canadian Cardiovascular Society (CCS) class II CHD, consisting of four treatment periods, each period lasting for 7-10 days. In the first period the patients received either oral levosimendan (LS) (0.5 mg) or placebo (PL) four times daily and were then crossed over to the other therapy for the second and third period. After the third period the patients were changed back to the therapy administered in the first period. Open label felodipine (FD), 5 mg once daily, was co-administered on the third and fourth treatment period. Differences between the four treatments (LS, PL, FD and LS + FD) in systolic time intervals, exercise capacity, heart rate, blood pressure and 24-hour continuous electrocardiography (Holter) were assessed.

RESULTS

The differences between treatments regarding heart rate corrected electromechanical systole (QS2i), pre-ejection period (PEP) and heart rate corrected left ventricular ejection time (LVETi) were significant (p < 0.001, p < 0.001 and p = 0.004, respectively). Levosimendan shortened QS2i by 10 ms (95% CI [-15, -4]), PEP by 6 ms (95% CI [-10, -3]) and LVETi by 7 ms (95% CI [-13, -2]) compared with placebo, indicating a moderate positive inotropic effect. The results were similar, when levosimendan was administered concomitantly with felodipine. Levosimendan did not significantly change systolic blood pressure and no potentiation of response was seen with concomitant administration with felodipine. The increase in heart rate after levosimendan and its combination with felodipine was equal (6-7 bpm). There was no difference in mean cumulative exercise time between the treatments. The combination of levosimendan and felodipine was well tolerated.

CONCLUSION

No clinically significant pharmacodynamic interactions between levosimendan and felodipine were seen. Levosimendan did not aggravate myocardial ischemia. Levosimendan can safely be administered to patients with CHD together with a dihydropyridine calcium antagonist.

Comparative effect of lercanidipine, felodipine, and nifedipine GITS on blood pressure and heart rate in patients with mild to moderate arterial hypertension: the Lercanidipine in Adults (LEAD) Study

This multicenter, double-blind, parallel-group study compared the effects of three dihydropyridine calcium channel blockers (lercanidipine, felodipine, and nifedipine gastrointestinal therapeutic system) on blood pressure and heart rate in 250 patients with mild to moderate hypertension (diastolic blood pressure > or =95 and 109 mm Hg). Patients were randomized to 4 weeks of treatment with once-daily doses of lercanidipine 10 mg, felodipine 10 mg, or nifedipine gastrointestinal therapeutic system 30 mg. After 4 weeks of treatment, the dose was doubled in nonresponding patients. At 8 weeks, no significant differences in blood pressure were observed among the three groups. Increases in heart rate in all three groups induced by stressful conditions before and after treatment were not exacerbated during active treatment. The incidence of adverse drug reactions was lower in the lercanidipine and nifedipine groups than in the felodipine group (p<0.05); in particular, the incidence of edema for lercanidipine was 5.5% vs. 13% for felodipine and 6.6% for nifedipine.

[The effect of analysed hypotensive drugs on certain metabolic parameters]

The aim of this study was to assess the influence of 3 hypotensive drugs on the metabolic disorders: dyslipidemia, insulin resistance, hyperuricemia. There were 39 patients aged 20-55, with mild-to-moderate essential hypertension. The patients with other serious diseases or treated earlier with cholesterol or uric acid lowering drugs were excluded. Patients were divided into 3 groups, each was treated during 8 weeks with one drug: gr 1--trandolapril (T), gr 2--felodipine ER (F), gr 3--rilmenidine (R). Glucose and insulin in oral glucose tolerance test, I/G proportion, serum lipids and uric acid were tested before and after therapy. The therapy did not influence lipid parameters: LDL, HDL, triglyceride. In the T group there could be observed a significant reduction of total cholesterol value. Examined drugs did not induce changes in serum carbohydrate. The significant reduction of serum uric acid could be observed only after F therapy. Analysed drugs are very useful in therapy of hypertension with metabolic disorders.

The effect of nonsteroidal anti-inflammatory drugs on blood pressure in patients treated with different antihypertensive drugs

Hypertension and arthritis are both common diseases in the older age group and require pharmacologic treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs) alter renal function if given in high enough doses, reducing renal blood flow and the glomerular filtration rate and causing sodium retention. In salt sensitive subjects, this retention of sodium will cause blood pressure to rise. Salt sensitivity is more common in elderly patients, in diabetics, and in people with renal failure. When most antihypertensive drugs are used, people become salt sensitive, as shown by the additive effect of salt restriction or diuretics on blood pressure response. The responses to dihydropyridine and possibly other calcium channel blocking drugs are not affected to any major extent by sodium intake or by diuretics. Studies are described which indicate that indomethacin elevates blood pressure in elderly people treated with enalapril, but not in people whose blood pressure is controlled with amlodipine or felodipine. It is unclear whether the various NSAIDs have different effects on blood pressure. It is proposed that if the same analgesic effect is achieved with the same amount of cyclooxygenase inhibition, the response will be similar. Aspirin, used in a prophylactic dose, does not inhibit to this extent and does not elevate blood pressure. If elderly people require NSAIDs, it would appear that dihydropyridine calcium channel blocking drugs are more effective at lowering and maintaining blood pressure control and should be one of the drugs used. If patients are on other antihypertensive agents, it is important to monitor blood pressure when a NSAID is added to therapy.

Smooth blood pressure control obtained with extended-release felodipine in elderly patients with hypertension: evaluation by 24-hour ambulatory blood pressure monitoring

OBJECTIVE

To assess, by smoothness index (SI), distribution of the antihypertensive effect of extended-release (ER) felodipine over 24 hours in elderly patients with hypertension.

METHODS

After a 4-week washout phase, 35 elderly patients (mean age 69 +/- 4 years) with mild-to-moderate hypertension received 2 weeks' treatment with ER felodipine 5mg once daily. The dosage of ER felodipine was doubled to 10 mg/day and given for a further 2 weeks in non-responders (sitting clinic blood pressure > 140/90mm Hg). The study had an open-label design with no placebo control. After each period, clinic and ambulatory blood pressures were measured. Trough-to-peak (T/P) ratio was computed by dividing the blood pressure (BP) change at trough (22 to 24 hours after drug intake) by the change at peak (2 adjacent hours with a maximal BP reduction between the second and eighth hour after drug intake). SI was calculated as the ratio between the average of the 24, hourly, treatment-induced BP changes and its standard deviation.

RESULTS

After the initial 2-week treatment period, clinic and 24-hour ambulatory BP values were higher in non-responders (145 +/- 11/87 +/- 8 and 135 +/- 17/80 +/- 6mm Hg, respectively) than in responders (133 +/- 6/81 +/- 3 and 130 +/- 9/77 +/- 7mm Hg). In non-responders, clinic and 24-hour BP values were lowered after a further 2 weeks of treatment with ER felodipine 10 mg/day (128 +/- 11/78 +/- 6 and 128 +/- 12/75 +/- 5mm Hg). SI was high in responders (0.8 +/- 0.8/0.7 +/- 0.7 for systolic/diastolic BP) and low in non-responders (0.5 +/- 0.6/0.3 +/- 0.6) during the first 2-week treatment period. It increased in non-responders after an additional 2 weeks of treatment with ER felodipine 10 mg/day (1.0 +/- 0.8/0.7 +/- 0.6). Median T/P ratios were 0.73 and 0.61 (systolic BP and diastolic BP) in responders and 0.41 and 0.61 in non-responders after 2 weeks of treatment. At variance with SI, T/P ratios did not increase in non-responders after doubling the dosage of ER felodipine (0.34 and 0.18). ER felodipine did not increase 24-hour heart rate. A total of nine adverse events were recorded in six patients (17%), but no patients withdrew from the study.

CONCLUSION

ER felodipine 5 to 10 mg/day smoothly and safely reduces 24-hour ambulatory BP in elderly patients with hypertension.

Efficacy and safety of barnidipine compared with felodipine in the treatment of hypertension in Chinese patients

The efficacy and safety profiles of barnidipine in the treatment of hypertension were evaluated in an open parallel-group study. Fifty-nine Chinese patients with mild-to-moderate essential hypertension were randomized to receive either barnidipine or felodipine (5 mg once daily, titrated to 10 mg or 15 mg once daily, as indicated) for 12 weeks. Both drugs reduced blood pressures significantly with > or = 68% of cases obtaining marked or moderate blood pressure reduction. Mean reductions in systolic and diastolic blood pressure for barnidipine treatment were 23.7 +/- 13.5 mmHg and 12.7 +/- 7.9 mmHg, and for felodipine, 24.3 +/- 18.4 mmHg and 14.5 +/- 10.0 mmHg, respectively. There was no significant difference between these two drugs in anti-hypertensive effect, heart rate, laboratory measurements or incidence of adverse events. The only difference was that more patients taking felodipine experienced palpitations. We conclude that barnidipine has similar efficacy and a similar safety profile to felodipine in the treatment of mild-to-moderate essential hypertension in Chinese patients.

One-year study of felodipine or placebo for stage 1 isolated systolic hypertension

Asubstantial number of older hypertensive patients have stage 1 isolated systolic hypertension (systolic blood pressure between 140 and 159 mm Hg and diastolic blood pressure <90 mm Hg), but there are currently no data showing that drug treatment is effective, safe, and/or beneficial. To compare the effects of active treatment compared with placebo on blood pressure, left ventricular hypertrophy, and quality of life among older stage 1 isolated systolic hypertensive patients, a randomized, double-blind, parallel-group, multicenter clinical trial comparing felodipine (2.5, 5, or 10 mg once daily) and matching placebo was performed in 171 patients (49% male, average age 66+/-7 years, with 49% white and 30% Hispanic) with a baseline blood pressure of 149+/-7/83+/-6 mm Hg. During 52 weeks of treatment, patients randomized to active treatment achieved significantly lower blood pressures (137.0+/-11.7/80.2+/-7.6 mm Hg for extended-release felodipine versus 147.5+/-16.0/83.5+/-9.7 mm Hg for placebo, P<0.01 for each), a reduced incidence of left ventricular hypertrophy (7% for extended release felodipine versus 24% for placebo, P<0.04), and improved quality of life (change in Psychological General Well-Being index, 3.0+/-6.8 for extended-release felodipine versus -0.8+/-10.3 for placebo, P<0.01) versus baseline. There were no clinically significant differences between treatments in tolerability or adverse effects. Stage 1 isolated systolic hypertension can be effectively and safely treated pharmacologically. Treatment reduced progression to the higher stages of hypertension, reduced the incidence of left ventricular hypertrophy, and improved an overall measure of the quality of life. Larger and longer studies will be needed to document any long-term reduction in cardiovascular event rates associated with treating stage 1 systolic hypertension.

A randomised trial to compare the efficacy and safety of Felodipine (Plendil) and Nifedipine (Adalat) retard in patients with mild-to-moderate hypertension

The efficacy and tolerability of Felodipine extended-release was compared with Nifedipine retard in the management of patients with mild-to-moderate hypertension. A total of one hundred and thirty three patients were screened out of which one hundred and twenty-one patients were enrolled in a 9-week multicentre open, randomised rising-dose trial to receive either Felodipine 5-10 mg once daily or Nifedipine 10-20 mg twice daily. Blood pressure was measured at the end of the dosing interval that is 24 hours and 12 hours after Felodipine and Nifedipine respectively. Both drugs, Felodipine and Nifedipine were found to lower blood pressure significantly compared with baseline. After three weeks of treatment, seated blood pressure was reduced by 20/14 mmHg (systolic/diastolic) and by 24/16 mmHg after 6 weeks in the felodipine group. Corresponding values in the Nifedipine group were 16/09 mmHg and 24/13mmHg. Pulse rate was not significantly affected by either drugs. The percentage of patients who had satisfactory control after 3 weeks treatment was 57.6% for Felodipine and 33.3% for Nifedipine (significant). After dose titration (where necessary), at the end of the study the response rates were 76.3% (n=45) and 79.6% (n=43) for Felodipine and Nifedipine respectively (non significant). Both drugs were metabolically inert and did not derange the haematologic and biochemical profile of patients. They produced no significant weight changes. The pattern of side effects were similar in both groups but tended to be more severe with Nifedipine necessitating withdrawal of two patients in this group. In conclusion, Felodipine ER 5mg - 10mg once daily, and Nifedipine Retard, 20mg twice daily were equally effective medications for mild-to-moderate hypertension but Felodipine was better tolerated.

Efficacy and safety of a therapeutic interchange from high-dose calcium channel blockers to a fixed-dose combination of amlodipine/benazepril in patients with moderate-to-severe hypertension

BACKGROUND

Recent hypertension trials have demonstrated the importance of achieving goal blood pressures to reduce the risk of target organ damage. In patients with moderate to severe hypertension, the use of high-dose monotherapy and/or combinations of drugs are necessary to achieve these goals. Fixed-dose combination products may be useful in these patients by reducing the number of daily doses required to control blood pressure.

OBJECTIVE

The objective of the present study was to evaluate the efficacy and safety of a therapeutic interchange between high-dose calcium channel blocker therapy and a fixed-dose combination of amlodipine/ benazepril (Lotrel; Novartis Pharmaceuticals, USA) in patients with moderate to severe hypertension.

METHODS

A total of 75 patients were switched from amlodipine (n = 25), felodipine (n = 25), and nifedipine-GITS (n = 25) to amlodipine/benazepril. Twenty-eight of the 75 patients (37%) were taking either a beta-blocker or a diuretic in addition to the high-dose calcium channel blocker prior to the switch. Blood pressure control, side effects and the cost of the therapeutic interchange were evaluated in the year following the therapeutic interchange.

RESULTS

Sixty-six of the 75 (88%) patients were successfully switched with maintenance of blood pressure control and without the development of new dose-limiting side effects. Reasons for treatment failure after the therapeutic interchange included loss of blood pressure control in five patients and the development of new dose-limiting side effects in four patients. These side effects included cough in three patients and rash in one patient. After accounting for differences in drug acquisition cost and costs related to the switch (clinic and emergency room and laboratory tests), a cost savings of $16030 for all 75 patients was realised in the first year. The per patient-per year cost savings was $214.

CONCLUSIONS

Our data indicate that a therapeutic interchange from selected high-dose calcium channel blockers to a fixed-dose combination of amlodipine/ benazepril can be successfully accomplished in the majority of patients.

[Effectiveness of felodipine in hypertensive patients with mild cerebral cognition disorders in a randomized double-blind study]

BACKGROUND AND OBJECTIVE

Cognitive impairment occurs more frequently in hypertensives than in normotensive individuals. Early signs of cognitive impairment are predictors of dementia in late life. Felodipine is capable of almost normalizing plasma viscosity, which is elevated in most of hypertensive patients, thus improving microcirculation. The aim of this study was to evaluate whether this hemorheologic property of felodipine in addition to its blood pressure lowering effect can improve cognitive performance in hypertensive patients.

PATIENTS AND METHODS

Randomized, double-blind comparison between felodipine 10 mg and hydrochlorothiazide 50 mg amiloride 5 mg (HCT/amiloride) in patients 50-70 years of age with impaired cognitive function (c.l. test 1-2 points) and with resting blood pressure values of diastolic > 95 and < or = 115 mmHg and/or systolic > 160 and < or = 210 mmHg. Blood pressure measurements and evaluation of total short term storage capacity were done at the beginning and after 12 weeks of treatment.

RESULTS

31 patients (14 felodipine and 17 HCT/amiloride) were included in the per protocol analysis. Blood pressure values at the beginning and after 12 weeks of treatment were (mmHg): for felodipine systolic 168 +/- 4 and 150 +/- 6 (p < 0.01), diastolic 108 +/- 3 and 88 +/- 4 (p < 0.001). For amiloride/HCT systolic 173 +/- 8 and 150 +/- 10 (p < 0.01), diastolic 105 +/- 5 and 88 +/- 5 (p < 0.001). Short term storage capacity improved by 15 +/- 6 bits during felodipine treatment (p < 0.001) and by 9 +/- 9 bits during amiloride/HCT treatment (p < 0.05). Thus cognitive improvement was superior by 67% in the felodipine group compared to amiloride/HCT (p < 0.05).

CONCLUSION

In this study a pronounced improvement of mental performance occurred in patients treated with felodipine. Since the cognitive gain was significantly superior to amiloride/HCT treatment there must be an additional blood pressure-independent effect of felodipine, such as enhancing microcirculation. Whether these properties possibly counteract the development of dementia in hypertensives has to be evaluated in long term studies in more patients.

Stroke precipitated by moderate blood pressure reduction

Rapid lowering of blood pressure can precipitate or worsen ischemic strokes. This usually has been observed in the setting of profoundly lowered pressure and hypotension. We report on six patients in whom ischemic neurologic injury ensued or worsened after moderate reduction of blood pressure by pharmacological treatment. The 6 patients suffered new or worsened ischemic neurologic deficits after receiving oral or intravenous antihypertensive medications, mostly after relatively small doses. Mean arterial blood pressure in these patients was decreased by 25 +/- 7.7%, or 37 +/- 16 mm Hg (mean +/- SD) without resultant hypotension. These cases emphasize the potential hazards of moderate blood pressure reduction by antihypertensive medications in the setting of an acute ischemic stroke or transient ischemic attack (TIA), as well as rapidly treated hypertension even in those who have not yet manifested ischemic symptoms.

The pharmacodynamic and pharmacokinetic profiles of controlled-release formulations of felodipine and metoprolol in free and fixed combinations in elderly hypertensive patients

AIMS

The aims of this study were to study the efficacy and tolerability of felodipine extended release (ER) 5 mg and metoprolol controlled release (CR/ZOC) 50 mg given as a fixed combination (Logimax) or as a free combination in elderly (age greater than 60 years) hypertensive patients, using ambulatory blood pressure (BP) monitoring. A secondary aim was to relate the efficacy of the free and fixed combinations with pharmacokinetic profiles.

METHODS

This was a double-blind, placebo-controlled randomised three-way crossover multi-centre study. BP was measured for 26 h using ambulatory blood pressure monitoring (ABPM), which was performed on the last day of the three treatment phases.

RESULTS

Mean sitting BPs, measured during the trough period with ABPM, were significantly lower with both the free and fixed combinations of metoprolol and felodipine than placebo (141/83 mmHg free, 140/83 mmHg fixed, 156/93 mmHg placebo). The mean BPs measured over 24 h using ABPM were 143/82 mmHg, 140/82 mmHg and 158/93 mmHg for the free, fixed and placebo treatment arms, respectively. The trough-to-peak ratios (T:P) were 75% and 79% for the systolic BP and 70% and 70% for the diastolic BP for the free and fixed combinations, respectively. Pharmacokinetic evaluation revealed identical plasma concentration-time curves for felodipine given as the free or fixed combination. Comparison of the plasma concentration-time curves for metoprolol revealed a delay in the release rate from the fixed combination formulation. No significant differences in BP control between the active treatments were noted during this period. Of 26 patients entered into the study, 3 withdrew during active phase for non-drug-related reasons. No patient withdrew from active treatment due to treatment-related adverse events. The frequency of adverse event reporting for the fixed combination of felodipine and metoprolol was similar to that for placebo (60% and 58%, respectively).

CONCLUSION

The results suggest that once-daily dosing with either the free or fixed combination of felodipine 5 mg and metoprolol 50 mg produces a significant sustained reduction in systolic and diastolic BP with similar plasma concentration profiles over a 24-h period.

Felodipine does not increase the reflux episodes in patients with gastroesophageal reflux disease

BACKGROUND/AIMS

Calcium channel blocking agents have been reported to increase the risk of gastroesophageal reflux. However, whether felodipine, a newer calcium channel blocker, increases reflux episodes and decreases esophageal acid clearance in patients with gastroesophageal reflux disease has never been studied. Therefore, the aim of this study was to evaluate whether felodipine increases the incidence of gastroesophageal reflux in patients with gastroesophageal reflux disorder.

METHODOLOGY

Nine patients with gastroesophageal reflux disease, 6 men and 3 women, with a mean age of 62.6 +/- 14.4 years (range: 37-80 years) were studied. They received ambulatory esophageal pH monitoring for 45.7-48 hours (mean: 47.1 +/- 0.8 hours). Various pH parameters were evaluated during a similar interval of monitoring time before and after receiving 5 mg of felodipine.

RESULTS

No significant difference was noted in any pH parameter by the Wilcoxon signed Ranks test, including reflux episodes (P = 0.552), reflux episodes longer than 5 min (P = 0.683), esophageal acid clearance (P = 0.663) and fraction time of pH < 4 (P = 0.752) before and after the use of felodipine.

CONCLUSIONS

Felodipine does not increase reflux episodes or impair esophageal acid clearance in patients with gastroesophageal reflux disease.

Incidence of gingival hyperplasia caused by calcium antagonists in continuous ambulatory peritoneal dialysis patients

Calcium antagonists are widely used for the treatment of cardiovascular diseases in patients receiving dialysis therapy. The incidence of gingival hyperplasia has been reported as 10%-20% in patients treated with calcium antagonists in the general population. However, precise reports examining the incidence or pathogenesis of gingival hyperplasia in continuous ambulatory peritoneal dialysis (CAPD) patients are lacking. We recruited 54 CAPD patients. Three patients treated with long-acting nifedipine and one patient treated with felodipine were reported by a periodontist to have gingival hyperplasia. No patients were taking amlodipine and other calcium antagonists. After discontinuation of calcium antagonists, gingival hyperplasia disappeared within 1 month. Based on these results, we suggest that it is important to examine whether the gingiva is overgrown in CAPD patients taking calcium antagonists.

[A critical analysis of the Hypertension Optimal Treatment (HOT) Study (appeared in Lancet 1998; 351: 1755-1762)]

In the HOT-study 18,790 patients in 26 countries (age 50-80 years, mean age 61.5 years) with hypertension (diastolic blood pressure between 100 and 115 mm Hg--mean value 105 mm Hg) were randomised into 3 groups with different target blood pressures (90 mm Hg, 85 mm Hg, 80 mm Hg). The basic treatment was with Felodipin (5 mg q. d.): if the target pressure was not achieved, further steps were initiated: either ACE-inhibitors or -blockers were added, in a third step the Felodipindose was increased to 100 mg and in a further step the doses of ACE-inhibitors or -blockers were doubled. If target pressure was still not achieved, a diuretic was added. Furthermore half of the patients in all groups received either placebo or 75 mg acetyl-salicylic acid. To prevent cardiovascular events the best benefit was shown, when a diastolic pressure of 82.6 mm Hg was reached. Acetyl-salicylic acid showed a further benefit in preventing myocardial infarction, but not in preventing strokes.

Vasodilatation with felodipine in chronic asymptomatic aortic regurgitation

BACKGROUND

Afterload reduction decreases volume overload on the left ventricle and may thereby delay the need for valve replacement in chronic asymptomatic aortic regurgitation. The aims of this randomized double-blind, placebo-controlled trial were to examine short- and long-term hemodynamic effects of felodipine in chronic asymptomatic aortic regurgitation.

METHODS

Sixteen patients were randomly assigned to an intravenous infusion of either felodipine 0. 3 mg or placebo followed by 3 months' treatment with felodipine 10 mg or placebo orally once daily. Magnetic resonance imaging was performed at baseline, immediately after intravenous treatment, and after 3 months of oral treatment.

RESULTS

Intravenous felodipine caused a statistically significant reduction in the systemic vascular resistance from (mean +/- SD) 1160 +/- 400 to 970 +/- 320 dynes. s. cm(-5) (P <.05), in the regurgitant volume index from 1.5 +/- 0.8 to 1.3 +/- 0.8 L. min(-1). m(-2) (P <.05), and in the regurgitant fraction from 0.31 +/- 0.15 to 0.26 +/- 0.14 (P <.05). The forward cardiac output index increased significantly from 3.2 +/- 0.9 to 3.5 +/- 0.7 L. min(-1). m(-2) (P <.05). Three months of oral treatment with felodipine caused a corresponding but more pronounced decrease in systemic vascular resistance of 880 +/- 330 dynes. s. cm(-5) (P <.05), regurgitant volume index of 1.2 +/- 0.7 L. min(-1). m(-2) (P <.05), and regurgitant fraction 0.25 +/- 0.11 (P <.05), whereas the forward cardiac output index increased to 3.6 +/- 0.7 L. min(-1). m(-2) (P <.05). No significant changes were found in the placebo group. Left ventricular volumes and ejection fraction remained unaffected by treatment, but compared with the placebo group left ventricular myocardial mass decreased significantly from 137 +/- 24 to 132 +/- 21 g. m(-2) (P <.01).

CONCLUSION

In chronic asymptomatic aortic regurgitation, felodipine causes beneficial hemodynamic effects that may postpone the need for valve replacement.

Felodipine/metoprolol: a review of the fixed dose controlled release formulation in the management of essential hypertension

The main objective of fixed dose combination therapy for hypertension is to improve blood pressure (BP) control with lower, better tolerated dosages of 2 antihypertensives rather than higher dosages of a single agent. Felodipine and metoprolol lower BP via different, but complementary, mechanisms and controlled release formulations of these 2 drugs are available as a fixed dose combination, felodipine/metoprolol. In clinical trials in patients with hypertension, felodipine/metoprolol was significantly more effective than placebo and the respective monotherapies administered at the same dosages. Mean BP was reduced to < 155/90 mm Hg in patients treated with combination therapy and controlled in approximately 70% of patients. In one study that titrated dosages to effect, fewer felodipine/metoprolol than felodipine or metoprolol monotherapy recipients required dosage increases to achieve BP control (45 vs 60 and 67%, respectively). Data from double blind comparative studies show that the antihypertensive efficacy of felodipine/metoprolol 5 to 10/50 to 100 mg/day is significantly greater than that of enalapril monotherapy or captopril plus hydrochlorothiazide and equivalent to nifedipine/atenolol and amlodipine. In comparisons with enalapril, fewer felodipine/metoprolol than enalapril recipients required dosage titration to achieve BP control. Compared with amlodipine, felodipine/metoprolol significantly reduced mean 24-hour average BP (8.9/5.5 vs 14.4/9.5 mm Hg after 6 weeks; p < 0.001). Both treatments preserved diurnal rhythm. Long term follow-up studies show that the antihypertensive effect of felodipine/metoprolol occurs mostly during the first month of treatment with small additional decreases in BP being observed in the second and third months, and a relatively constant effect thereafter. According to a validated questionnaire, quality of life was relatively similar during 12 weeks treatment with felodipine/metoprolol, enalapril or placebo. In a retrospective pharmacoeconomic analysis conducted in Sweden, felodipine/metoprolol was more cost effective than enalapril as initial treatment for hypertension. Peripheral oedema, headache and flushing were the most commonly reported adverse events with felodipine/metoprolol and felodipine monotherapy, whereas dizziness, fatigue, headache and respiratory infection were more frequent with metoprolol monotherapy. Dose-dependent adverse events such as oedema may occur less often in patients taking lower dosages in combination than in those taking higher dosages of felodipine monotherapy. Thus, patients with hypertension treated with felodipine/metoprolol experience greater control of BP, with less need for dosage titration, than those treated with felodipine, metoprolol or enalapril monotherapy. Importantly this greater efficacy does not appear to be associated with a higher incidence of adverse events relative to monotherapy. Additionally, in short term studies felodipine/metoprolol had a similar (minimal) effect on QOL to enalapril monotherapy but was more cost effective.

Cross-over comparison of nifedipine Oros and felodipine extended release with blind 24 h ambulatory blood pressure assessments

1. The aim of the present study was to compare the efficacy of nifedipine Oros and felodipine extended release (ER) in controlling 24 h ambulatory blood pressures (ABP) in hypertensive patients. 2. The study was a randomized cross-over design with a 2 week open placebo run-in phase and two observer-blind treatment periods. 3. Subjects were males and females, aged between 18 and 65 years, suffering from mild to moderate essential hypertension with a sitting mean diastolic blood pressure (DBP) within the range of 95-114 mmHg. Twenty-three subjects were randomized to treatment; 15 patients completed the study. 4. Treatment intervention was 2 weeks of placebo followed by either 30 mg nifedipine OROS once daily or 5 mg felodipine ER once daily for 6 weeks, which was titrated up to 60 mg nifedipine OROS daily or 10 mg felodipine ER daily after 2 weeks of treatment on the lower doses if the DBP was > 90 mmHg. The main outcome measure was 24 h ABP after 6 weeks of active treatment, evaluated by an independent observer blinded as to treatment allocation. 5. Compared with placebo, mean (+/- SD) 24 h DBP was reduced by 6.2 +/- 6.8 and 5.2 +/- 5.1 mmHg after nifedipine and felodipine, respectively. The 24 h mean systolic blood pressure (SBP) fell by 11.8 +/- 10.9 and 10.1 +/- 8.2 mmHg for nifedipine and felodipine, respectively, compared with placebo. There were no significant differences between the two active treatments in the reduction of DBP or SBP during the 24 h period, daytime or night-time. 6. Similar antihypertensive effects are achieved with nifedipine Oros and felodipine ER when doses are individually titrated, with no significant differences between the two treatments.

Comparison of clinical efficacy and adverse effects between extended-release felodipine and slow-release diltiazem in patients with isolated systolic hypertension

BACKGROUND

Isolated systolic hypertension (ISH) is a risk factor for cardiovascular disease. Extended-release felodipine (felodipine ER) has been shown to be effective in the treatment of ISH in Caucasians. However, its pharmacological properties are different from another calcium blocker, diltiazem. Also, the effectiveness, tolerability, and adverse reactions of these two antihypertensive agents for ISH have not been thoroughly assessed in Chinese.

METHODS

Sitting blood pressures (BP), heart rate, body weight, adverse reactions, and serum biochemistry were assessed in 70 patients with isolated systolic hypertension (34 treated with felodipine ER and 36 slow-release diltiazem [diltiazem SR] for 10 weeks). Each patient was given 5 mg of felodipine ER or 90 mg of diltiazem SR once daily and was doubled to twice daily if necessary.

RESULTS

Five patients on felodipine ER and four on diltiazem SR withdrew because of intolerable side effects. By ten weeks, 67.6% of the patients responded to a daily dose of 5-10 mg of felodipine ER and 58.3% to a daily dose of 90-180 mg of diltiazem SR. At the end of treatment, felodipine ER lowered the mean BP from 187/83 mmHg at baseline to 149/74 mmHg, whereas diltiazem SR decreased the BP from 185/84 mmHg to 158/78 mmHg (not significant between the two groups). The heart rate did not change significantly in either group. Overall, these two groups of patients had the same rate of adverse reactions (50.0% vs. 50.0%) with similar profiles of the adverse effects.

CONCLUSION

Equivalent doses of felodipine ER and diltiazem SR are effective first-line monotherapeutic agents for the treatment of ISH.

Improved efficacy with maintained tolerability in the treatment of primary hypertension. Comparison between the felodipine-metoprolol combination tablet and monotherapy with enalapril. Swedish Multicentre Group

In this multicentre, double-blind, parallel-group study, 120 out-patients with mild to moderate primary hypertension were randomised, after a 4-week single-blind placebo run-in period, to a combination tablet of felodipine-metoprolol 5/50 mg (Logimax, Mobloc, Astra) once daily or enalapril 10 mg once daily. If blood pressure (BP) remained suboptimally controlled after 4 weeks (supine diastolic BP >90 mm Hg 24-h post dose), the dose was doubled for a further 4 weeks. After 8 weeks felodipine-metoprolol reduced supine BP significantly more than enalapril (19.7/12.0 mmHg and 11.1/7.2 mm Hg, respectively). The mean differences in change in BP between treatments were 8.6/4.8 mm Hg in favour of felodipine-metoprolol (P = 0.001/P <0.001). A statistically significant difference to the advantage of felodipine-metoprolol was also seen in standing BP. Even though the dose was increased in a larger proportion of patients in the enalapril group (61%) than in the felodipine-metoprolol group (40%), fewer enalapril-treated patients achieved adequate BP control (41% vs 63% on felodipine-metoprolol, P <0.05). Both treatments were well tolerated. Three patients treated with felodipine-metoprolol and four with enalapril discontinued treatment due to adverse events. A similar number of patients reported adverse events in each treatment group. In conclusion, a combination tablet of felodipine-metoprolol 5/50-10/100 mg once daily reduced BP more effectively than enalapril 10-20 mg once daily 24 h post dose. The result was expected, but a more important observation was that both treatments were tolerated to a similar degree. Obviously, a considerable BP reduction may be well tolerated, as was the main purpose to demonstrate in this study.

Combination therapy with felodipine and metoprolol compared with captopril and hydrochlorothiazide. German MC Study Group

This study compared the antihypertensive efficacy and tolerability of a combination tablet containing the vascular-selective calcium antagonist felodipine and the beta1-selective adrenergic antagonist metoprolol, with a combination tablet of captopril-hydrochlorothiazide in a randomized, double-blind trial involving 109 patients with mild to moderate hypertension. After 2 weeks on placebo, patients with a supine diastolic blood pressure of 95-115 mm Hg were randomized to felodipine-metoprolol, 5/50 mg o.d. (Logimax) or captopril-hydrochlorothiazide, 25/25 mg o.d. (Capozide). After a further 4 weeks, there was a mandatory dose increase to felodipine-metoprolol 10/100 mg o.d., and captopril-hydrochlorothiazide, 50/25 mg o.d., and treatment then continued for a another 4 weeks. At the end of the study, felodipine-metoprolol reduced supine blood pressure significantly more than captopril-hydrochlorothiazide. The mean differences in change in supine systolic and diastolic blood pressure between treatments after 8 weeks were 5.2 and 3.4 mm Hg, respectively, in favour of felodipine-metoprolol (p<0.05). Standing blood pressure also showed trends in favour of felodipine-metoprolol. The proportion of responders was similar in both groups. Both treatments were well tolerated. Two patients treated with felodipine-metoprolol and 5 with captopril-hydrochlorothiazide discontinued treatment due to adverse events. Felodipine-metoprolol combination reduced supine blood pressure significantly more than captopril-hydrochlorothiazide with maintained tolerability.

Amlodipine, felodipine, and isradipine in the treatment of Chinese patients with mild-to-moderate hypertension

Optimal treatment of hypertension requires the use of effective antihypertensive drugs. Calcium channel blockers are widely used in the treatment of hypertension and appear to be particularly efficacious in ethnic Chinese patients. The aim of this open-label study was to prospectively investigate the efficacy and tolerability of three dihydropyridine calcium channel blockers in sequence, using the same protocol for each. After 2 weeks of placebo treatment, 73 males and 45 females (mean age, 45 +/- 10 years; mean weight, 67 +/- 10 kg) with essential hypertension (diastolic blood pressure, 95 to 115 mm Hg) were treated with amlodipine (n = 41), felodipine (n = 38), or isradipine (n = 39) for 8 weeks, with dose titration after 4 weeks. Mean seated systolic and diastolic blood pressure decreased by 23/17, 30/17, and 20/15 mm Hg after 8 weeks of treatment with amlodipine, felodipine, and isradipine, respectively. These reductions were all statistically significant. Blood pressure was controlled (defined as diastolic pressure < 90 mm Hg at the final visit or a decrease from baseline of > or = 10 mm Hg) in 85%, 74%, and 74% of patients receiving amlodipine, felodipine, and isradipine, respectively. There were no significant changes in heart rate, plasma lipid levels, or serum biochemistry markers with any of the three treatments. No serious adverse events occurred, but mild adverse effects, including headaches, flushing, tachycardia, dizziness, and edema, were reported; 1 (2%), 6 (16%), and 5 (13%) patients receiving amlodipine, felodipine, and isradipine, respectively, withdrew from the study (P < 0.05). The results of this study indicate that all three drugs are highly effective in lowering blood pressure and are well tolerated in Chinese patients with mild-to-moderate hypertension.

Influence of calcium antagonist drugs in myasthenia gravis in the elderly

A number of drugs have been reported to cause neuromuscular blockade and/or to increase weakness in myasthenia gravis. We report on two patients, treated with felodipine and nifedipine for arterial hypertension, who presented with an exacerbation of their myasthenia gravis and a myasthenic syndrome or exacerbation of myasthenia gravis, respectively. The mechanism of action of calcium antagonist drugs at the neuromuscular junction is not yet well established, but it could be located at both presynaptic and postsynaptic levels.

Improved tolerability of felodipine compared with amlodipine in elderly hypertensives: a randomised, double-blind study in 535 patients, focusing on vasodilatory adverse events. The International Study Group

The primary aim of this double-blind, parallel group trial was to compare incidence of newly occurring vasodilatory adverse events in elderly patients treated with recommended once-daily doses of felodipine extended release (ER) or amlodipine. A total of 535 patients over 65 years old with a sitting diastolic blood pressure of 90-115 mmHg and/or systolic blood pressure 160-220 mmHg, were recruited at 46 centres worldwide. Patients were randomised to felodipine ER 2.5 mg or amlodipine 5 mg. If blood pressure was > 160/90 mmHg after three or six weeks, felodipine ER was increased to 5 and 10 mg and amlodipine to 10 mg. After nine weeks, average doses of felodipine ER and amlodipine were 5.5 mg and 7.3 mg, respectively. Newly occurring vasodilatory adverse events were reported by 32% of felodipine ER patients and 43% of amlodipine patients (p = 0.007). Both treatments effectively reduced blood pressure 24 hours post-dose. Using a low starting dose and individual titration, felodipine ER achieves good control of blood pressure with few vasodilatory side-effects.

Felodipine-induced gingival hyperplasia

Felodipine is a calcium channel blocking agent used in the management of hypertension and angina. We report a case of gingival hyperplasia in a patient with chronic use of this drug. Gingival changes occurred soon after initiation of felodipine and improved upon its discontinuation. The clinical characteristics, inciting agents, proposed pathogenetic mechanisms, as well as prevention and treatment of drug-induced gingival hyperplasia are briefly reviewed.

A comparison of the antihypertensive efficacy and safety of felodipine IV and nifedipine IV in patients with hypertensive crisis or emergency not responding to oral nifedipine

OBJECTIVE

A clinical definition of a hypertensive emergency is excessively high blood pressure in the presence of symptoms indicating end organ damage. Equally high blood pressure without symptoms is called a hypertensive crisis. Patients with hypertensive crisis or emergency need prompt, effective, and specific therapy and a controlled reduction of blood pressure.

METHODS

We performed a randomized, double-blind multi-centre study, to compare the safety, efficacy and tolerability of an intravenous (i.v.) infusion of two dihydropyridine calcium channel blockers (either nifedipine or felodipine) in 122 patients, of whom 63 were diagnosed as hypertensive emergencies and 59 as hypertensive crisis, who had not reacted adequately (diastolic blood pressure <115 mmHg) to 5 mg of nifedipine PO.

RESULTS

Both drugs lowered blood pressure adequately in more than 90% of the patients and were well tolerated. Only one patient had to be withdrawn, because of an excessive decrease in blood pressure.

CONCLUSION

Patients with excessively high blood pressure who do not react to oral nifedipine can be treated equally effectively with felodipine and nifedipine IV. Felodipine is easier to handle because of its lack of light sensitivity.

Long-term efficacy, tolerability, and safety of the combination of enalapril and felodipine ER in the treatment of hypertension. Enalapril-Felodipine ER Factorial Study Group

A recent 8-week, double-masked, placebo-controlled, 3 x 4 factorial-design study demonstrated that enalapril-felodipine extended-release (ER) combinations had statistically significant additive effects for reducing both sitting systolic blood pressure (SiSBP) and sitting diastolic blood pressure (SiDBP) and were generally well tolerated in hypertensive patients with SiDBPs ranging from 95 to 115 mm Hg. The present open-label study was undertaken to assess the long-term efficacy, tolerability, and safety of such combinations. Patients from the factorial study were eligible for the 1-year, open-label extension. Initially, all patients received enalapril 5 mg-felodipine ER 2.5 mg once daily; if SiDBP was not controlled (< 90 mm Hg) after 4 weeks of treatment, the dose was titrated upward at 2- to 4-week intervals to a maximum of enalapril 10 mg-felodipine ER 10 mg. Hydrochlorothiazide (HCTZ) 12.5 mg was added to the regimen of patients whose hypertension was not controlled at the highest enalapril-felodipine ER dose. A total of 507 patients were enrolled, of whom 502 were assessable. At their last study visit, 391 (78%) of the assessable patients were receiving only an enalapril-felodipine ER combination. The enalapril-felodipine ER combinations resulted in mean trough SiDBPs of 85 to 89 mm Hg (decreases of 13 to 16 mm Hg from baseline) and SiSBPs of 137 to 140 mm Hg (decreases of 13 to 21 mm Hg). Overall, 407 (81%) of the 502 assessable patients achieved an SiDBP < 90 mm Hg or a reduction from baseline > or = 10 mm Hg (responders); such a response was recorded in 331 patients (66%) taking a combination of enalapril-felodipine ER alone and 76 patients (15%) taking the combination with the addition of HCTZ 12.5 mg. Blood pressure reductions were maintained throughout the treatment period. Drug-related adverse events were relatively infrequent, often transient, usually mild, and apparently not dose related. The most frequently reported drug-related adverse events were edema/swelling, asthenia/fatigue, dizziness, cough, and headache. These results suggest that combination therapy with enalapril-felodipine ER is effective for long-term blood pressure reduction, has an excellent safety profile, and is generally well tolerated. Addition of low-dose HCTZ to the enalapril-felodipine ER combination appears to provide further blood pressure control without increasing drug-related adverse events.

The interaction effect of grapefruit juice is maximal after the first glass

OBJECTIVE

To compare the acute effect of grapefruit juice intake on the pharmacokinetics and haemodynamic effects of felodipine ER tablets with the interaction after 14 days intake of drug with juice.

METHODS

Twelve healthy male volunteers were included in this cross-over trial and randomly allocated to a daily intake of a 10-mg felodipine extended release tablet with water or grapefruit juice for 14 days. The two study periods were separated by at least 14 days. The pharmacokinetics of felodipine and dehydrofelodipine, as well as the haemodynamic effects of the drug, were studied during day 1 and 14 in each period.

RESULTS

Similarly to previous single-dose studies, the treatment during the first day with grapefruit juice increased the AUC (+73%) and Cmax (+138%) of felodipine when compared with the control treatment. On day 14 a similar effect of grapefruit juice was observed, with an increased AUC24 (+57%) and Cmax (+114%) of felodipine compared with the control experiment. A significant accumulation of felodipine occurred during both the control (+37%) and grapefruit juice (+25%) period. The extent of accumulation was not significantly different in the two treatment periods. The pharmacokinetics of the metabolite dehydrofelodipine were affected to a similar extent by the juice on day 1 and day 14. The first dose of felodipine together with grapefruit juice was associated with a significant additional increase in heart rate when compared with the control therapy, whereas there was no additional effect on blood pressure when therapy included grapefruit juice. On day 14 the intake of drug with juice resulted in an additional increase in heart rate and reduction in diastolic blood pressure in comparison with the control experiment. Furthermore, the vascularly related adverse events were more frequent in the period including grapefruit juice.

CONCLUSION

The interaction between grapefruit juice and felodipine appears to be already fully developed after the first glass of grapefruit juice, as the change in pharmacokinetics in comparison with the control experiment is similar on day 1 and on day 14. Concomitant intake of 10 mg felodipine ER and the juice is associated with increased haemodynamic effects in healthy subjects both after a single dose and following 14 days of concomitant intake.