Cost-effectiveness analysis of combining traditional Chinese medicine in the treatment of hypertension: compound Apocynum tablets combined with Nifedipine sustained-release tablets vs Nifedipine sustained-release tablets alone.

BACKGROUND: We evaluated the long-term cost-effectiveness of antihypertensive traditional Chinese medicines (TCMs) and to compare the cost-effectiveness of a combined treatment consisting of compound Apocynum tablets and Nifedipine sustained-release tablets with the cost-effectiveness of treatment with Nifedipine sustained-release tablets alone. METHODS: A Markov model was used to simulate the potential incremental cost-effectiveness per quality-adjusted life year (QALY) to be gained from compound Apocynum tablets and Nifedipine sustained-release tablets compared with Nifedipine sustained-release tablets alone. Model parameter estimates were informed by previously published studies. The direct medical costs of outpatients with hypertension were estimated from the health care provider's perspective. A 5% annual discount rate was applied to both costs and QALYs. RESULTS: TCMs combined with Nifedipine sustained-release tablets group generated a total 20-year cost of 11,517.94 RMB (US $1739.87), whereas Nifedipine sustained-release tablets alone group resulted in a 20-year cost of 7253.71 RMB (US $1095.73). TCMs combined with Nifedipine sustained-release tablets group resulted in a generation of 12.69 QALYs, whereas Nifedipine sustained-release tablets alone group resulted in 12.50. The incremental cost-utility ratio was 22,443.32 RMB (US $3390.23) per QALY. Considering the threshold of 1 GDP per capita in China in 2018 (US $9764.95), the combination of compound Apocynum tablets and Nifedipine sustained-release tablets was a cost-effective strategy. One-way and probabilistic sensitivity analysis showed unchanged results over an acceptable range. CONCLUSIONS: Combining Traditional Chinese Medicines with chemical medicines is more cost-effective strategy in the treatment of hypertension.

Cost effectiveness of nifedipine compared with atosiban in the treatment of threatened preterm birth (APOSTEL III trial).

OBJECTIVE: To assess the cost-effectiveness of treatment with nifedipine compared with atosiban in women with threatened preterm birth. DESIGN: An economic analysis alongside a randomised clinical trial (the APOSTEL III study). SETTING: Obstetric departments of 12 tertiary hospitals and seven secondary hospitals in the Netherlands and Belgium. POPULATION: Women with threatened preterm birth between 25 and 34 weeks of gestation, randomised for tocolysis with either nifedipine or atosiban. METHODS: We performed an economic analysis from a societal perspective. We estimated costs from randomisation until discharge. Analyses for singleton and multiple pregnancies were performed separately. The robustness of our findings was evaluated in sensitivity analyses. MAIN OUTCOME MEASURES: Mean costs and differences were calculated per woman treated with nifedipine or atosiban. Health outcomes were expressed as the prevalence of a composite of adverse perinatal outcomes. RESULTS: Mean costs per patients were significantly lower in the nifedipine group [singleton pregnancies: €34,897 versus €43,376, mean difference (MD) -€8479 [95% confidence interval (CI) -€14,327 to -€2016)]; multiple pregnancies: €90,248 versus €102,292, MD -€12,044 (95% CI -€21,607 to € -1671). There was a non-significantly higher death rate in the nifedipine group. The difference in costs was mainly driven by a lower neonatal intensive care unit admission (NICU) rate in the nifedipine group. CONCLUSION: Treatment with nifedipine in women with threatened preterm birth results in lower costs when compared with treatment with atosiban. However, the safety of nifedipine warrants further investigation. TWEETABLE ABSTRACT: In women with threatened preterm birth, tocolysis using nifedipine results in lower costs when compared with atosiban.

Oral nifedipine versus intravenous labetalol for severe hypertension during pregnancy: a systematic review and meta-analysis.

BACKGROUND: Oral nifedipine is recommended along with labetalol and hydralazine for treatment of severe hypertension during pregnancy by most authorities. Although nifedipine is cheap and easily administered, the usage pattern among health care providers suggests a strong preference for labetalol despite lack of evidence for the same. OBJECTIVES: To determine the efficacy and safety of oral nifedipine for treatment of severe hypertension of pregnancy compared with intravenous labetalol. SEARCH STRATEGY: We systematically searched for articles comparing oral nifedipine with intravenous labetalol for the treatment of severe hypertension during pregnancy in any language, over Medline, Cochrane Central Register of Clinical Trials and Google Scholar from inception till February 2014. SELECTION CRITERIA: We included all RCTs that compared intravenous labetalol with oral nifedipine for treatment of severe hypertension during pregnancy, addressing relevant efficacy and safety outcomes. DATA COLLECTION AND ANALYSIS: Eligible studies were reviewed, and data were extracted onto a standard form. We used Cochrane review manager software for quantitative analysis. Data were analysed using a fixed effect model. MAIN RESULTS: The pooled analysis of seven trials (four from developing countries) consisting of 363 woman-infant pairs showed that oral nifedipine was associated with less risk of persistent hypertension (RR 0.42, 95% CI 0.18-0.96) and reported maternal side effects (RR 0.57, 95% CI 0.35-0.94). However, on sensitivity analysis the outcome 'persistent hypertension' was no longer significant. Other outcomes did not reach statistical significance. CONCLUSION: Oral nifedipine is as efficacious and safe as intravenous labetalol and may have an edge in low resource settings. TWEETABLE ABSTRACT: Although studies to date are few in number and small, nifedipine shows promise for severe hypertension in pregnancy.

Use of drug therapy in the management of symptomatic ureteric stones in hospitalised adults: a multicentre, placebo-controlled, randomised controlled trial and cost-effectiveness analysis of a calcium channel blocker (nifedipine) and an alpha-blocker (tamsulosin) (the SUSPEND trial).

BACKGROUND: Ureteric colic, the term used to describe the pain felt when a stone passes down the ureter from the kidney to the bladder, is a frequent reason for people to seek emergency health care. Treatment with the muscle-relaxant drugs tamsulosin hydrochloride (Petyme, TEVA UK Ltd) and nifedipine (Coracten(®), UCB Pharma Ltd) as medical expulsive therapy (MET) is increasingly being used to improve the likelihood of spontaneous stone passage and lessen the need for interventional procedures. However, there remains considerable uncertainty around the effectiveness of these drugs for routine use. OBJECTIVES: To determine whether or not treatment with either tamsulosin 400 µg or nifedipine 30 mg for up to 4 weeks increases the rate of spontaneous stone passage for people with ureteric colic compared with placebo, and whether or not it is cost-effective for the UK NHS. DESIGN: A pragmatic, randomised controlled trial comparing two active drugs, tamsulosin and nifedipine, against placebo. Participants, clinicians and trial staff were blinded to treatment allocation. A cost-utility analysis was performed using data gathered during trial participation. SETTING: Urology departments in 24 UK NHS hospitals. PARTICIPANTS: Adults aged between 18 and 65 years admitted as an emergency with a single ureteric stone measuring ≤ 10 mm, localised by computerised tomography, who were able to take trial medications and complete trial procedures. INTERVENTIONS: Eligible participants were randomised 1 : 1 : 1 to take tamsulosin 400 µg, nifedipine 30 mg or placebo once daily for up to 4 weeks to make the following comparisons: tamsulosin or nifedipine (MET) versus placebo and tamsulosin versus nifedipine. MAIN OUTCOME MEASURES: The primary effectiveness outcome was the proportion of participants who spontaneously passed their stone. This was defined as the lack of need for active intervention for ureteric stones at up to 4 weeks after randomisation. This was determined from 4- and 12-week case-report forms completed by research staff, and from the 4-week participant self-reported questionnaire. The primary economic outcome was the incremental cost per quality-adjusted life-year (QALY) gained over 12 weeks. We estimated costs from NHS sources and calculated QALYs from participant completion of the European Quality of Life-5 Dimensions health status questionnaire 3-level response (EQ-5D-3L™) at baseline, 4 weeks and 12 weeks. RESULTS: Primary outcome analysis included 97% of the 1167 participants randomised (378/391 tamsulosin, 379/387 nifedipine and 379/399 placebo participants). The proportion of participants who spontaneously passed their stone did not differ between MET and placebo [odds ratio (OR) 1.04, 95% confidence interval (CI) 0.77 to 1.43; absolute difference 0.8%, 95% CI -4.1% to 5.7%] or between tamsulosin and nifedipine [OR 1.06, 95% CI 0.74 to 1.53; absolute difference 1%, 95% CI -4.6% to 6.6%]. There was no evidence of a difference in QALYs gained or in cost between the trial groups, which means that the use of MET would be very unlikely to be considered cost-effective. These findings were unchanged by extensive sensitivity analyses around predictors of stone passage, including sex, stone size and stone location. CONCLUSIONS: Tamsulosin and nifedipine did not increase the likelihood of stone passage over 4 weeks for people with ureteric colic, and use of these drugs is very unlikely to be cost-effective for the NHS. Further work is required to investigate the phenomenon of large, high-quality trials showing smaller effect size than meta-analysis of several small, lower-quality studies. TRIAL REGISTRATION: Current Controlled Trials ISRCTN69423238. European Clinical Trials Database (EudraCT) number 2010-019469-26. FUNDING: This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 63. See the NIHR Journals Library website for further project information.

Use of drug therapy in the management of symptomatic ureteric stones in hospitalized adults (SUSPEND), a multicentre, placebo-controlled, randomized trial of a calcium-channel blocker (nifedipine) and an α-blocker (tamsulosin): study protocol for a randomized controlled trial.

BACKGROUND: Urinary stone disease is common, with an estimated prevalence among the general population of 2% to 3%. Ureteric stones can cause severe pain and have a significant impact on quality of life, accounting for over 15,000 hospital admissions in England annually. Uncomplicated cases of smaller stones in the lower ureter are traditionally treated expectantly. Those who fail standard care or develop complications undergo active treatment, such as extracorporeal shock wave lithotripsy or ureteroscopy with stone retrieval. Such interventions are expensive, require urological expertise and carry a risk of complications.Growing understanding of ureteric function and pathophysiology has led to the hypothesis that drugs causing relaxation of ureteric smooth muscle, such as the selective α-blocker tamsulosin and the calcium-channel blocker nifedipine, can enhance the spontaneous passage of ureteric stones. The use of drugs in augmenting stone passage, reducing the morbidity and costs associated with ureteric stone disease, is promising. However, the majority of clinical trials conducted to date have been small, poor to moderate quality and lacking in comprehensive economic evaluation.This trial aims to determine the clinical and cost-effectiveness of tamsulosin and nifedipine in the management of symptomatic urinary stones. METHODS/DESIGN: The SUSPEND (Spontaneous Urinary Stone Passage ENabled by Drugs) trial is a multicentre, double-blind, randomized controlled trial evaluating two medical expulsive therapy strategies (nifedipine or tamsulosin) versus placebo.Patients aged 18 to 65 with a ureteric stone confirmed by non-contrast computed tomography of the kidney, ureter and bladder will be randomized to receive nifedipine, tamsulosin or placebo (400 participants per arm) for a maximum of 28 days. The primary clinical outcome is spontaneous passage of ureteric stones at 4 weeks (defined as no further intervention required to facilitate stone passage). The primary economic outcome is a reduction in the incremental cost per quality-adjusted life years, determined at 12 weeks. The analysis will be based on all participants as randomized (intention to treat). The trial has 90% power with a type I error rate of 5% to detect a 10% increase in primary outcome between the tamsulosin and nifedipine treatment groups. TRIAL REGISTRATION: ISRCTN69423238; EudraCT number: 2010-019469-26.

An examination of the clinical benefits and cost-effectiveness of tocolytic replacement following recurrent preterm labor.

We examined pregnancy outcomes in women receiving nifedipine tocolysis having recurrent preterm labor (RPTL). Singleton gestations enrolled for outpatient nursing surveillance and prescribed nifedipine tocolysis were identified (N = 4748). Women hospitalized for RPTL at <35 weeks then resuming outpatient surveillance were included (N = 1366). Pregnancy outcomes of women resuming nifedipine (N = 830) were compared with those having an alteration in treatment to continuous subcutaneous terbutaline (N = 536). Overall, 56.7% (2692/4748) experienced RPTL. Half (50.7%) were stabilized and resumed outpatient surveillance with nifedipine or continuous subcutaneous terbutaline. Infants from women resuming nifedipine versus those with alteration of treatment to terbutaline were more likely to deliver at <35 weeks (28.0% versus 13.8%), weigh <2500 g (32.9% versus 20.3%), and require a stay in the neonatal intensive care unit (34.0% versus 23.1%), all P < 0.001. Alteration of tocolytic treatment following RPTL resulted in a decreased incidence of preterm birth and low birth weight, resulting in less admission to the neonatal intensive care unit and fewer nursery days.

Cost-effectiveness analysis: controlled-release nifedipine and valsartan combination therapy in patients with essential hypertension: the adalat CR and valsartan cost-effectiveness combination (ADVANCE-Combi) study.

As recommended by the guidelines such as JSH 2004, combination therapy with multiple agents is now being applied to many patients with hypertension. However, a pharmacoeconomic analysis of each therapy has not been fully undertaken in Japan, despite increasing societal interest. In this study, the cost-effectiveness of two calcium channel blockers, each coadministered with an angiotensin receptor blockade, was compared using data from the ADVANCE-Combi study. The ADVANCE-Combi study was a 16-week double-blind, randomized clinical trial to compare the efficacy and safety of two combination therapies (controlled-release nifedipine [nifedipine CR] plus valsartan vs. amlodipine plus valsartan) on blood pressure (BP) control in patients with moderate to severe essential hypertension. The incremental cost effectiveness of each cohort was compared from the perspective of insurers. The average total cost per patient was Japanese yen (JPY) 31,615 for the nifedipine CR treatment group and JPY 35,399 for the amlodipine treatment group (p < 0.001). The achievement rate of the target BP (SBP/DBP < 130/85 mmHg for patients aged under 60 years; SBP/DBP < 140/90 mmHg for those aged 60 years and over) was significantly higher in the nifedipine CR treatment group (61.2%) than in the amlodipine treatment group (34.6%) (p < 0.001), with no difference in the incidence of drug-related adverse events. Accordingly, the base case economic analysis demonstrated that the nifedipine CR treatment group was dominant (more efficacious and less costly) to the amlodipine treatment group. This result was supported by univariate and probabilistic sensitivity analyses. These results indicate that nifedipine CR-based combination therapy is superior to amlodipine-based combination therapy for the management of essential hypertension in the Japanese population.

Evaluation of zero-order controlled release preparations of nifedipine tablet on dissolution test, together with cost benefit point of view.

Many generic drugs have been released to decrease medical expenses, but some problems have been reported with regard to bioavailability and safety. In this study, we compared three once-a-day controlled-release preparations of nifedipine by the dissolution test (one branded and two generic preparations). Although the two generic drugs were equivalent to the branded drug according to the criteria listed in the Japanese "Guideline for Bioequivalence Studies of Generic Products", there was still a possibility of problems arising. For example, side effects could be caused by a rapid increase in the blood level of nifedipine with one generic drug, while bioavailability might be inadequate with the other due to its small area under the concentration vs. time curve. When each drug was prescribed at a dosage of 20 mg once daily for two weeks, the difference in the copayment for the patient was only 10 yen. Accordingly, it is important for doctors and pharmacists to carefully consider whether such a slight difference in price is really a benefit for the patient.

A cost decision analysis of 4 tocolytic drugs.

OBJECTIVE: The purpose of this study was to determine the optimal tocolytic agent, based on a cost decision analysis. STUDY DESIGN: A PubMed search of commonly used tocolytics was performed to determine the probability of adverse events. Cost for an agent was determined by acquisition cost and the probability and cost of adverse events. A decision tree was constructed to determine which tocolytic had the lowest total costs, with subsequent sensitivity analysis. RESULTS: A total of 19 clinical trials combined for a cohort of 1073 patients (indomethacin, 176 patients; magnesium sulfate, 451 patients; nifedipine, 176 patients; and terbutaline, 270 patients). The probability of adverse events was 57.9% for terbutaline, 22.0% for magnesium sulfate, 27.2% for nifedipine, and 11.4% for indomethacin. Nifedipine ($16.75) and indomethacin ($15.40) were the least expensive treatment options, compared with magnesium sulfate ($197.90) and terbutaline ($399.02) because of the cost of monitoring and treating adverse events. CONCLUSION: If one elects a tocolytic, both nifedipine and indomethacin should be the agents of choice, based on a cost decision analysis.

Resource utilization implications of treatment were able to be assessed from appropriately reported clinical trial data.

BACKGROUND AND OBJECTIVE: Published clinical trial data rarely allow assessment of the health care resource utilization implications of treatment. We give an example of how these can be assessed given appropriate tabulation of data. METHODS: Data from a trial comparing long-acting nifedipine gastrointestinal therapeutic system to placebo in 7,665 patients with stable angina pectoris was analyzed. RESULTS: Relative to placebo, nifedipine significantly increased mean cardiovascular (CV) event-free survival by 41 days but had no effect on mean survival. Per 100 years of follow-up, 78.1 patient-years of double-blind nifedipine administration reduced use of another calcium antagonist, an angiotensin converting enzyme inhibitor, an angiotensin receptor blocker, a diuretic and a cardiac glycoside by 1.54, 3.73, 2.63, 2.23, and 0.64 years, respectively, whereas 0.21 less hospitalization for overt heart failure, 0.47 less hospitalization for any stroke or transient ischemic attack, 0.8 less coronary angiogram, 0.38 less coronary bypass procedure, and 0.13 additional orthopedic procedure was required. Combining resource utilization with cost data for one particular hospital showed that one additional year of CV event-free survival costs an average additional euro 3,036 in the setting considered. CONCLUSION: Appropriately tabulated clinical trial data allows clinicians to judge the resource utilization implications and economic effect of treatment decisions.

Controlled release nifedipine and valsartan combination therapy in patients with essential hypertension: the adalat CR and valsartan cost-effectiveness combination (ADVANCE-combi) study.

This study was designed to compare the clinical efficacy of two calcium channel blocker-based combination therapies with an angiotensin receptor blocker in Japanese patients with essential hypertension. A 16-week, double-blind, parallel-arm, randomized clinical trial was performed to compare the efficacy and safety of the combination therapy of controlled release nifedipine (nifedipine CR) plus valsartan vs. that of amlodipine plus valsartan. The primary endpoint was the target blood pressure achievement rate. Eligible patients were randomly allocated to nifedipine CR-based or amlodipine-based treatment groups. Patients were examined every 4 weeks to determine whether the blood pressure had reached the target level. When the target level was not achieved, the drug regimen was changed; when the target blood pressure was achieved, the same study medication was continued. A total of 505 patients were enrolled in the study (nifedipine CR group: 245 cases; amlodipine group: 260 cases). After 16 weeks of treatment, blood pressure was significantly reduced in both groups, but to a larger extent in the nifedipine CR group than in the amlodipine group (p < 0.01). The target blood pressure achievement rate was also significantly higher in the nifedipine CR group (p < 0.001). There was no significant difference in the incidence of drug-related adverse events between the groups. These results indicate that the nifedipine CR-based combination therapy was superior to the amlodipine-based therapy for decreasing blood pressure and achieving the target blood pressure in patients with essential hypertension.

Cost-effectiveness analysis of hypertension treatment: controlled release nifedipine and candesartan low-dose combination therapy in patients with essential hypertension--the Nifedipine and Candesartan Combination (NICE-Combi) Study.

Societal interest in pharmaco-economic analysis is increasing in Japan. In this study, the cost-effectiveness of low-dose combination therapy with controlled release nifedipine plus candesartan and up-titrated monotherapy with candesartan was estimated, based on the results of the NICE-Combi study. The NICE-Combi study was a double-blind, parallel arm, randomized clinical trial to compare the efficacy of low-dose combination therapy of controlled release nifedipine (20 mg/day) plus candesartan (8 mg/day) vs. up-titrated monotherapy of candesartan (12 mg/day) on blood pressure control in Japanese patients with mild to severe essential hypertension who were not sufficiently controlled by the conventional dose of candesartan (8 mg/ day). The incremental cost effectiveness of each cohort during the 8-week randomization period was compared, from the perspective of a third-party payer (i.e., insurers). The average total cost per patient was 29,943 Japanese yen for the combination therapy group and 33,182 Japanese yen for the candesartan monotherapy group, while the rate of achievement of the target blood pressure was significantly higher in the combination therapy group than in the up-titrated monotherapy group. In the combination therapy group, higher efficacy and lower incremental treatment cost ("Dominance") were observed when compared to the monotherapy group. The sensitivity analyses also supported the results. In conclusion, these results suggest that combination therapy with controlled release nifedipine and low-dose candesartan (8 mg) is "dominant" to up-titrated candesartan monotherapy for the management of essential hypertension. This conclusion was robust to sensitivity analysis.

Pharmacist-managed hypertension therapy conversion.

The cost of treating hypertension represents a substantial percentage of total pharmacy expenditures at medical centers and by managed care organizations in the United States. The present study evaluated improvements in blood pressure control and cost savings achieved by switching 543 hypertensive patients from nifedipine gastrointestinal therapeutic system (GITS) to amlodipine and concurrently instituting an educational program directed at prescribers, nursing and pharmacy staff, and patients and family members. Before the switch, 543 patients were being treated with nifedipine GITS: 259 with 30 mg/d, 209 with 60 mg/d, and 75 with 90 mg/d. The total annual cost of primary antihypertensive therapy for this patient population was $184,698. All patients were switched from nifedipine GITS to 5 mg of amlodipine. The pharmacist saw patients at the time of the switch and at 2, 4, and 6 to 8 weeks after the change in antihypertensive therapy. Patients who did not achieve systolic blood pressure < or = 140 mm Hg or diastolic blood pressure < or = 90 mm Hg by 6 to 8 weeks after the switch were titrated to 10 mg/d amlodipine. After the conversion, 417 patients were receiving amlodipine 5 mg/d and 126 patients were ultimately titrated to 10 mg/d. Measurements made during the first 6 to 8 weeks of treatment indicated that amlodipine therapy significantly reduced blood pressure. Overall, amlodipine produced further mean reductions in blood pressure, from 140/82 to 130/76 mm Hg (p < 0.00005). The mean reduction from the time of the switch to 6 to 8 weeks was from 138/81 to 129/74 mm Hg for the patients who received 5 mg/d amlodipine (p < 0.00001) and from 147/85 to 133/79 mm Hg for the patients ultimately titrated to 10 mg/d amlodipine (p < 0.05). The total annual cost for primary antihypertensive therapy after the conversion was $136,854. We observed that conversion from nifedipine GITS to amlodipine enhanced blood pressure control and saved $47,844 in the annual cost of primary antihypertensive medication. For the 543 patients undergoing the switch, annual cost savings was $47,844. When the cost of additional antihypertensive agents discontinued after the switch to amlodipine was added to the analysis, the net annual cost savings increased to $49,578, a 27% reduction in yearly drug costs.

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.

Evaluation of amlodipine dosing for conversion of nifedipine extended-release to amlodipine in the treatment of hypertension.

OBJECTIVE: To evaluate the appropriate dosing of amlodipine when converting patients from nifedipine extended-release (nifedipine ER) to amlodipine in the treatment of hypertension. METHODS: Patients of the Outpatient Clinic of Cheyenne Veterans Affairs Medical Center, Wyoming, receiving nifedipine ER for the management of hypertension (systolic BP or SBP > 140 mm Hg and diastolic BP or DBP > 90 mm Hg), participated in this study. Nifedipine ER was changed to amlodipine on entry into this study. An inclusion criterion was the BP had to be under control (SBP < 140 mm Hg and DBP < 90 mm Hg) before the switch. The BP in each study patient was monitored once weekly (once every 2 wk in some patients) for a total of six clinic visits or until BP was under control. Dosing titration of amlodipine was required in 16 of 27 patients after the switch. To assess the adequacy of the conversion, the statistical significance of the difference of the mean BP values before and at the end of the monitoring period was estimated by using the t-test for paired data. RESULTS: Twenty-seven male patients completed this study. BP in all study patients was adequately controlled after nifedipine ER was switched to amlodipine. The SBP and DBP values before and after the switch were similar (SBP: 124 +/- 12 vs. 126 +/- 9 mm Hg, CI of the mean difference -6.10 to 1.80; DBP: 76 +/- 8 vs. 76 +/- 7 mm Hg, CI of the mean difference -2.45 to 3.63). Initial amlodipine dose of 5 or 10 mg once daily was used in our study. No serious adverse effects were observed in any of the study patients after the drug switch. CONCLUSIONS: This study indicates the amlodipine dosage of 5 or 10 mg once daily can be used when nifedipine ER is converted to amlodipine in the treatment of hypertension. Dosage titration of amlodipine may be required to obtain adequate control of BP.

Clinical pharmacokinetics of nifedipine. Implications for the care of the elderly.

Nifedipine, the prototype for the dihydropyridine class of calcium antagonists, has been available for 20 years and its efficacy as a vasodilator and an antihypertensive agent is well recognised. The development of the so-called nifedipine gastrointestinal therapeutic system (GITS), which allows once-daily administration, has modified and improved the overall therapeutic profile of nifedipine to such a significant extent that it might almost be considered a new drug entity. The nifedipine GITS is associated with distinct improvements in terms of patient compliance and convenience, and a reduced incidence of adverse effects. With regard to the care of the elderly, this 'new' drug offers the prospect of a well tolerated and effective treatment without major cost implications.

Nifedipine gastrointestinal therapeutic system versus nifedipine coat-core: comparison of efficacy via 24-hour ambulatory blood pressure monitoring.

OBJECTIVE: To assess the comparable efficacy and adverse effect profile of two extended-release preparations of nifedipine--gastrointestinal therapeutic system (GITS) and coat-core (CC)--in patients with mild-to-moderate hypertension. DESIGN: Single institution, single-blind, prospective study. SETTING: Dwight David Eisenhower Army Medical Center, Fort Gordon, GA. PATIENTS: Ninety-one patients who were taking nifedipine GITS as a sole antihypertensive agent were randomized to receive either GITS or CC. After 3 weeks, 24-hour ambulatory blood pressure monitoring was conducted and an adverse effect questionnaire was administered. The patients were then crossed over to the other treatment arm and monitoring was repeated after 3 weeks. MEASUREMENTS: Mean blood pressure, heart rates, and the percentage of readings exceeding 140 mm Hg systolic and 90 mm Hg diastolic were compared for the 24-hour period. Additionally, mean blood pressures at 4-hour intervals after drug administration and heart rate during the first 8 hours of the dosage interval were compared. RESULTS: Ninety-one patients enrolled, 79 completed the study, and 62 patients were included in the efficacy analysis. A statistically significant difference (p = 0.020) was shown only in the last 4-hour systolic blood pressure. However, this difference was small (122 +/- 15 mm Hg with GITS vs. 126 +/- 14 mm Hg with CC). There was no difference in the percentage of readings exceeding 140 mm Hg systolic or 90 mm Hg diastolic. Neither dosage nor treatment order had an effect on the results. Adverse effects were reported with a greater frequency during CC therapy (40 with CC vs. 22 with GITS; p = 0.006), but were generally transient. Discontinuation of the drug was necessary in 3 patients during the CC cycle. CONCLUSIONS: GITS and CC demonstrated clinically equivalent antihypertensive efficacy in the study population. The CC produce may have a higher rate of adverse effects, but drug discontinuation was uncommon.

A randomised crossover comparison of reserpine and sustained-release nifedipine in hypertension.

OBJECTIVE: To compare the effectiveness of the combination of hydrochlorothiazide (HCT) plus sustained-release nifedipine with the combination of HCT plus reserpine in lowering high blood pressure (BP) unresponsive to HCT monotherapy. DESIGN: An open, randomised crossover drug trial. SETTING: Outpatients' clinic in Parirenyatwa Hospital, Harare, a tertiary referral centre. SUBJECTS: 32 Black patients of both sexes with newly diagnosed or previously treated hypertension aged between 21 and 65 years who had a BP > 140/95 after receiving HCT 25 mg daily for four weeks were studied. INTERVENTION: Patients were kept on HCT 25 mg daily and were randomised to receive either reserpine 0.25 mg daily or nifedipine (Adalat Retard) 20 mg bd for four weeks. This was followed by a two week washout period during which patients received HCT 25 mg daily only. After the washout period patients were crossed over to the alternative treatment for four weeks. Patients were kept on HCT 25 mg daily throughout the trial. MAIN OUTCOME MEASURES: The main outcome measure was the fall in BP which was taken as the difference between the BP at baseline and the BP at the end of each treatment period. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements were taken. RESULTS: Both second line drugs were effective in lowering SBP and DBP and there was no significant difference between them. Nifedipine reduced SBP by 18.9 mmHg (95% CI 12.1 to 25.7) and DBP by 9.6 mmHg (95% CI 7.2 to 12.0). Reserpine reduced SBP by 15.9 mmHg (95% CI 8.4 to 23.4) and DBP by 11.1 mmHg (95% CI 7.5 to 14.6). However, only two patients attained the target DBP of < or = 90 mmHg after each active treatment period. CONCLUSION AND RECOMMENDATIONS: Since both agents were equally effective in reducing both SBP and DBP and reserpine is much cheaper than nifedipine, it is recommended that for a developing country like Zimbabwe, the combination of HCT and reserpine at the above doses should be used as the first step to treat mild to moderate hypertension without evidence of end organ damage. However, further trials should compare BP lowering effects as well as end organ protection offered by the trial drugs.

The costs and effects of switching calcium channel blockers: evidence from Medicaid claims data.

This study used Medicaid claims data from Pennsylvania to examine the costs and effects of changing calcium channel blocker therapies. Specifically, we compared Procardia XL with Adalat CC. They are the only once-daily-dosed, extended-release forms of nifedipine available. These drugs were interesting to compare for several reasons. First, because the frequency of treatment regimens has been shown to be the most important determinant of long-term compliance with calcium channel blocker medications, it was desirable to compare drugs having identical dosing regimens. Second, switching from one to the other should be quite feasible in most patients. Third, Adalat CC is priced (ie, average wholesale price) less than Procardia XL. The results indicate that prescription prices were lower when patients were switched from Procardia XL to Adalat CC, with no apparent effects on blood pressure control, the incidence of adverse drug reactions, or nonprescription health care costs. The potential savings to Medicaid from switching patients from Procardia XL to Adalat CC appears to be large, more than $2.5 million annually for Procardia XL-treated Medicaid patients in the state of Pennsylvania. Our study also demonstrates that large retrospective databases can be used to evaluate economic and clinical outcomes for specific therapy alternatives. Such evaluations are increasingly relevant to third-party payers, health maintenance organizations, and other parties involved in managed care.