The effects of cinacalcet on blood pressure, mortality and cardiovascular endpoints in the EVOLVE trial.

Patients with end-stage renal disease often have derangements in calcium and phosphorus homeostasis and resultant secondary hyperparathyroidism (sHPT), which may contribute to the high prevalence of arterial stiffness and hypertension. We conducted a secondary analysis of the Evaluation of Cinacalcet Hydrochloride Therapy to Lower Cardiovascular Events (EVOLVE) trial, in which patients receiving hemodialysis with sHPT were randomly assigned to receive cinacalcet or placebo. We sought to examine whether the effect of cinacalcet on death and major cardiovascular events was modified by baseline pulse pressure as a marker of arterial stiffness, and whether cinacalcet yielded any effects on blood pressure. As reported previously, an unadjusted intention-to-treat analysis failed to conclude that randomization to cinacalcet reduces the risk of the primary composite end point (all-cause mortality or non-fatal myocardial infarction, heart failure, hospitalization for unstable angina or peripheral vascular event). However, after prespecified adjustment for baseline characteristics, patients randomized to cinacalcet experienced a nominally significant 13% lower adjusted risk (95% confidence limit 4-20%) of the primary composite end point. The effect of cinacalcet was not modified by baseline pulse pressure (Pinteraction=0.44). In adjusted models, at 20 weeks cinacalcet resulted in a 2.2 mm Hg larger average decrease in systolic blood pressure (P=0.002) and a 1.3 mm Hg larger average decrease in diastolic blood pressure (P=0.002) compared with placebo. In summary, in the EVOLVE trial, the effect of cinacalcet on death and major cardiovascular events was independent of baseline pulse pressure.

Cinacalcet HCI (Sensipar/Mimpara) is an effective chronic therapy for hemodialysis patients with secondary hyperparathyroidism.

AIMS: This 1-year double-blind, placebo-controlled, multicenter study evaluated the long-term safety and efficacy of cinacalcet for the treatment of secondary hyperparathyroidism in patients receiving hemodialysis. METHOD: Patients were randomly assigned in a 1:1 ratio to cinacalcet or control treatment groups. The initial dose of cinacalcet (or matching placebo) was 30 mg. Doses were titrated every 3 or 4 weeks based on the intact parathyroid hormone (iPTH) response and safety profile. Sequential doses included 30, 60, 90, 120 and 180 mg/d. Phosphate binders and vitamin D sterols were adjusted per protocol as needed to control levels of calcium and phosphorus. Efficacy and safety were compared between treatment groups among patients who completed the study (52 total weeks of treatment). Reasons for withdrawal are presented for patients who did not complete the study. RESULTS: A total of 210 patients completed 52 weeks of double-blinded treatment with cinacalcet (n = 99) or placebo (n = 111). Over the last 6 months of the study, a greater proportion of patients in the cinacalcet group than the control group achieved an iPTH level < or = 250 pg/ml (61.6 vs. 9.9%, p < 0.001) or a > or = 30% decrease in iPTH from baseline (81.8 vs. 21.6%, p < 0.001). Mean iPTH levels decreased by -47.8% in the cinacalcet group and increased by +12.9% in the control group. Mean percentage changes in other laboratory values in the cinacalcet and control groups included the following: serum calcium -6.5 vs. +0.9% (p < 0.001), serum phosphorus -3.6 vs. -1.1% (p = 0.465), and Ca x P -9.9 vs. -0.3% (p = 0.006). The most commonly reported adverse events related to study drug by the investigators included nausea (13% cinacalcet, 5% control), investigator-reported hypocalcemia (11% cinacalcet, 1% control), vomiting (9% cinacalcet, 2% control), dyspepsia (5% cinacalcet, 4% control), and diarrhea (5% cinacalcet, 2% control). CONCLUSIONS: Treatment with cinacalcet is a safe and effective therapy for long-term control of secondary hyperparathyroidism. 1-year therapy with cinacalcet was associated with sustained, clinically significant reductions in calcium, Ca x P and iPTH which allowed a greater percentage of patients to achieve NKF-KDOQI target goals for PTH and Ca x P.

Association of pulse wave velocity with vascular and valvular calcification in hemodialysis patients.

The recent Kidney Disease: Improving Quality Outcomes (KDIGO) recommendations called for an investigation of the relationship between various radiological methods to assess cardiovascular calcification and measures of arterial stiffness. Accordingly, in 131 adult maintenance hemodialysis patients, we investigated the association of aortic pulse wave velocity (PWV) with calcification of cardiac valves on echocardiography, coronary artery, and thoracic aorta calcium on computed tomography and a calcification score of the abdominal aorta obtained on a plain abdominal X-ray. All tests were performed within a week. Mean PWV increased as the severity of coronary artery, thoracic, and abdominal aorta calcium scores increased (each P<0.05). No trend was present for number of valves with calcification. After multivariable adjustment, abdominal aorta X-ray calcium scores remained associated with PWV (P=0.004), whereas the association of PWV with thoracic aorta and coronary artery calcium scores became marginal (P=0.308 and P=0.083, respectively). No association was found between number of calcified valves and PWV. This study demonstrates a strong association between abdominal aorta calcification on plain X-ray and PWV and a borderline association with thoracic aorta and coronary artery calcification. Sudden death and congestive heart failure, two frequent causes of death in hemodialysis, are likely caused by increased arterial stiffness that can be closely predicted by the presence of aortic calcification on plain X-rays.

Mortality effect of coronary calcification and phosphate binder choice in incident hemodialysis patients.

The risk of death in hemodialysis patients treated with calcium-containing phosphate binders or sevelamer is not known. We assessed all-cause mortality in 127 patients new to hemodialysis assigned to calcium-containing binders or sevelamer after a median follow-up of 44 months from randomization. This was a predetermined secondary end point of a randomized clinical trial designed to assess progression of coronary artery calcium (CAC) scores in the two treatment arms. Thirty-four deaths occurred during the follow-up period: 23 in subjects randomized to calcium-containing phosphate binders and 11 in subjects randomized to sevelamer. Baseline CAC score was a significant predictor of mortality after adjustment for age, race, gender, and diabetes with increased mortality proportional to baseline score (P=0.002). Mortality was borderline significantly lower in subjects randomized to sevelamer (5.3/100 patient years, confidence interval (CI) (2.2-8.5) compared to those randomized to calcium-containing binders (10.6/100 patient years, CI 6.3-14.9) (P=0.05). The greater risk of death for patients treated with calcium-containing phosphate binders persisted after full multivariable adjustment (P=0.016, hazard ratio 3.1, CI 1.23-7.61). In subjects new to hemodialysis baseline CAC score was a significant predictor of all-cause mortality. Treatment with sevelamer was associated with a significant survival benefit as compared to the use of calcium-containing phosphate binders.

Correlation of simple imaging tests and coronary artery calcium measured by computed tomography in hemodialysis patients.

Vascular calcification is associated with an adverse prognosis in end-stage renal disease. It can be accurately quantitated with computed tomography but simple in-office techniques may provide equally useful information. Accordingly we compared the results obtained with simple non-invasive techniques with those obtained using electron beam tomography (EBT) for coronary artery calcium scoring (CACS) in 140 prevalent hemodialysis patients. All patients underwent EBT imaging, a lateral X-ray of the lumbar abdominal aorta, an echocardiogram, and measurement of pulse pressure (PP). Calcification of the abdominal aorta was semiquantitatively estimated with a score (Xr-score) of 0-24 divided into tertiles, echocardiograms were graded as 0-2 for absence or presence of calcification of the mitral and aortic valve and PP was divided in quartiles. The CACS was elevated (mean 910+/-1657, median 220). The sensitivity and specificity for CACS > or = 100 was 53 and 70%, for calcification of either valve and 67 and 91%, respectively, for Xr-score > or = 7. The area under the curve for CACS > or = 100 associated with valve calcification and Xr-score was 0.62 and 0.78, respectively. The likelihood ratio (95% confidence interval) of CACS > or = 100 was 1.79 (1.09, 2.96) for calcification of either valve and 7.50 (2.89, 19.5) for participants with an Xr-score > or = 7. In contrast, no association was present between PP and CACS. In conclusion, simple measures of cardiovascular calcification showed a very good correlation with more sophisticated measurements obtained with EBT. These methodologies may prove very useful for in-office imaging to guide further therapeutic choices in hemodialysis patients.

Rofecoxib: no effect on Alzheimer's disease in a 1-year, randomized, blinded, controlled study.

BACKGROUND: Inflammatory mechanisms have been implicated in the pathogenesis of Alzheimer's disease (AD) and may be mediated via the cyclo-oxygenase-2 enzyme. This study sought to evaluate the effect of rofecoxib, a nonsteroidal anti-inflammatory drug that selectively inhibits cyclo-oxygenase-2, in slowing the progression of dementia in patients with established AD. METHODS: A double-blinded, multicenter trial was conducted in which 692 patients with mild or moderate AD aged 50 years or older were randomly assigned to receive 25 mg rofecoxib or placebo daily for 12 months. The key efficacy measures were mean change from baseline at month 12 on the cognitive subscale of the AD Assessment Scale (ADAS-cog) and score on the Clinician's Interview Based Impression of Change with caregiver input (CIBIC+). RESULTS: Four hundred eighty-one patients (70%) completed assessments and remained on treatment at 12 months. No significant differences between treatments were found on the mean change from baseline error score for the ADAS-cog (rofecoxib = 4.84; placebo = 5.44; difference = -0.60) or mean score on the CIBIC+ (rofecoxib = 4.90; placebo = 4.87; difference = 0.03) over 12 months. This result persisted after adjusting for severity of dementia at baseline, presence of the APOE-epsilon4 allele, and donepezil use. Secondary analyses did not reveal any significant differences on any other measures. CONCLUSION: The failure of selective cyclo-oxygenase-2 inhibition to slow the progression of AD may indicate either that the disease process is too advanced to modify in patients with established dementia or that cyclo-oxygenase-2 does not play a significant role in the pathogenesis of the disorder.

Control of serum phosphorus: implications for coronary artery calcification and calcific uremic arteriolopathy (calciphylaxis).

There is mounting evidence that elevated serum phosphorus is an important cardiovascular risk factor in patients with end stage renal disease. Recent work has shown that vascular smooth muscle cells have the ability to undergo osteoblastic differentiation and produce an environment conducive to mineralization. Serum phosphorus is an important stimulator of this process and the adverse cardiovascular effects of hyperphosphatemia are most likely mediated via its ability to enhance the development of vascular calcification. Arterial calcification, whether it is intimal or medial in location, is a strong independent risk factor for cardiovascular morbidity and mortality. Both coronary artery calcification and calciphylaxis are prototypical examples of arterial calcification that have been associated with poor phosphate control. Furthermore, several investigators have recently suggested that the prescription of large doses of calcium to achieve phosphate control may augment, rather than diminish, the risk of vascular calcification. This is more likely to be true in the presence of low turnover bone disease, a diagnosis difficult to make with routine laboratory testing. A brief review of the molecular biology of vascular calcification supports the concept that warfarin administration may exacerbate the calcific process, particularly in the setting of hyperphosphatemia, as has been reported in patients with calciphylaxis. Recognizing the consequences of poor phosphate control, it is time to adopt strict target levels that aim to normalize serum phosphorus levels. The available evidence supports that this control should not be achieved through the use of supraphysiologic doses of supplemental calcium.

Prevalence and clinical consequences of elevated Ca x P product in hemodialysis patients.

Control of serum phosphorus (P) levels is a central goal of managing patients with chronic renal failure (CRF). Hyperphosphatemia develops invariably with kidney failure, and inadequate control of serum P leads to an elevated calcium-phosphorus (Ca x P) product. Further contributing to an elevated Ca x P product is the fact that hemodialysis patients are generally in a net positive calcium balance-dietary intake of calcium, ingestion of calcium-based phosphate binders, calcium absorption from dialysate, and abnormalities in bone buffering and turnover all contribute to the calcium burden in hemodialysis patients. In addition, treatment with calcitriol to manage secondary hyperparathyroidism increases intestinal absorption of both calcium and P. These abnormalities in divalent ion metabolism can result in a number of harmful conditions in CRF patients, including vascular calcification, cardiovascular disease, calciphylaxis, and death. We are now beginning to realize that our current therapeutic approaches to CRF management may not only be ineffective in controlling P and Ca x P product, but may actually contribute to serious calcific and cardiovascular hazards in these patients. Elevated P and Ca x P product are both significant predictors of cardiovascular mortality in hemodialysis patients. These effects are observed at P and Ca x P product levels that were considered safe until recently. Based on current national studies, we now recommend that serum P levels and Ca x P product of patients with CRF be maintained between 3.0-5.0 mg/dl and less than 55 mg2/dl2, respectively. Achieving these more rigorous treatment goals will require a shift in our therapeutic management strategies to incorporate aggressive use of calcium-free phosphate binders and, when necessary, use of less calcemic vitamin D analogs.

Re-evaluation of risks associated with hyperphosphatemia and hyperparathyroidism in dialysis patients: recommendations for a change in management.

Hyperphosphatemia is a predictable consequence of chronic renal failure and is present in most patients on dialysis. Traditionally, the risk associated with elevated serum phosphorus has focused on its impact on renal osteodystrophy. A growing body of evidence, however, suggests that abnormalities in serum phosphorus, calcium-phosphorus product (CaxP), and parathyroid hormone (PTH) levels are resulting in vascular and visceral calcification, thereby contributing to the substantially increased risk of cardiovascular death in this population. In this analysis, we review in detail the literature that describes these associations. We show that the current treatment paradigm for serum phosphorus and secondary hyperparathyroidism is ineffective for a large segment of dialysis patients. Currently, 60% of hemodialysis patients have phosphorus greater than 5.5 mg/dL, and 40% have CaxP greater than 60 mg(2)/dL(2). It is our belief that prevention of uremic calcification, cardiac death, and vascular disease should assume primary importance when evaluating the risks associated with elevated levels of phosphorus, CaxP, and PTH. We recommend that target levels should become 9.2 to 9.6 mg/dL for calcium, 2.5 to 5.5 mg/dL for phosphorus, less than 55 mg(2)/dL(2) for CaxP product, and 100 to 200 pg/mL for intact PTH.

Validation of a migraine work and productivity loss questionnaire for use in migraine studies.

Migraine symptoms and therapy side effects cause significant functional disability that can result in work and productivity losses. Effective, well-tolerated migraine therapy with rapid onset of relief could decrease work and productivity losses. The Migraine Work and Productivity Loss Questionnaire (MWPLQ) evaluates the impact of migraine and migraine therapy on paid work. Data from a randomized, open-label extension study were collected over 3 months. Migraineurs were randomized to either rizatriptan (5HT1B/1D receptor agonist) or their usual migraine therapy. Data were analyzed from 164 patients who experienced at least one work-related migraine. Internal consistency (Cronbach's alpha) for the work difficulty domains ranged from 0.80 to 0.95. Work loss and work difficulty were moderately correlated (r = 0.39-0.58) with migraine severity and functional ability. Differences were found favoring rizatriptan for absenteeism (1.3 vs 2.4 h), effectiveness at work (62% vs 49%), and difficulty with work-related tasks (p < 0.01). The MWPLQ demonstrated favorable measurement characteristics in this study and could be an important research tool for future evaluations of migraine-related work disability.

Efficacy and safety of rizatriptan wafer for the acute treatment of migraine. Rizatriptan Wafer Protocol 049 Study Group.

Rizatriptan is a potent, highly selective 5HT1B/1D agonist with rapid onset of action for acute treatment of migraine. Rizatriptan wafer is a novel, freeze-dried dosage formulation of rizatriptan which rapidly disintegrates on the tongue, is swallowed with saliva, and may be taken without liquids. The efficacy and tolerability of rizatriptan wafer were examined in a placebo-controlled, double-blind, outpatient study in 555 migraineurs. The primary efficacy endpoint was pain relief at 2 h. From 30 min onwards, significantly more patients experienced pain relief and became pain-free after rizatriptan 10-mg wafer compared to placebo. At 2 h, the percentage of patients with pain relief was significantly higher after rizatriptan 10-mg wafer (74%), 5-mg wafer (59%) compared with placebo (28%). Rizatriptan 10-mg wafer was superior to rizatriptan 5-mg wafer on pain relief at 1.5 and 2 h (p < 0.05). Significantly more patients were pain-free at 2 h after rizatriptan 10-mg wafer (42%), 5-mg wafer (35%) compared with placebo (10%). Both doses of rizatriptan wafer were well tolerated. Rizatriptan wafer is a convenient, highly effective new formulation for acute treatment of migraine.

Association of serum phosphorus and calcium x phosphate product with mortality risk in chronic hemodialysis patients: a national study.

Elevated serum phosphorus is a predictable accompaniment of end-stage renal disease (ESRD) in the absence of dietary phosphate restriction or supplemental phosphate binders. The consequences of hyperphosphatemia include the development and progression of secondary hyperparathyroidism and a predisposition to metastatic calcification when the product of serum calcium and phosphorus (Ca x PO4) is elevated. Both of these conditions may contribute to the substantial morbidity and mortality seen in patients with ESRD. We have analyzed the distribution of serum phosphorus in two large national, random, cross-sectional samples of hemodialysis patients who have been receiving dialysis for at least 1 year. Data were obtained from two special studies of the United States Renal Data System, the Case Mix Adequacy Study (1990) and the Dialysis Morbidity and Mortality Study Wave 1 (1993). The relative risk of death by serum phosphorus quintiles is described after adjusting for age at onset of ESRD, race, sex, smoking status, and the presence of diabetes, the acquired immunodeficiency syndrome, and/or neoplasm. Logistic regression analysis is then used to describe the demographic, comorbid, and laboratory parameters associated with high serum phosphorus. Serum phosphorus was similar in these two study populations and averaged 6.2 mg/dL. Ten percent of patients had levels greater than 9 mg/dL and at least 30% of each group had serum phosphorus levels greater than 7 mg/dL. The adjusted relative risk of death by serum phosphorus level was not uniform across all quintiles, being constant below a level of 6.5 mg/dL and increasing significantly above this level. The relative risk of death for those with a serum phosphorus greater than 6.5 mg/dL was 1.27 relative to those with a serum phosphorus of 2.4 to 6.5 mg/dL. This increased risk was not diminished by statistical adjustment for coexisting medical conditions, delivered dose of dialysis, nutritional parameters, or markers of noncompliance. Evaluation of predictors of serum phosphorus greater than 6.5 mg/dL revealed in multivariate analysis that younger age at onset of ESRD, female sex, white race, diabetes, active smoking, and higher serum creatinine levels were all significant predictors. Analysis of serum calcium revealed no correlation with relative risk of death. The Ca x PO4 product, however, showed a mortality risk trend similar to that seen with serum phosphorus alone. Those in the highest quintile of the Ca x PO4 product (>72 mg2/dL2) had a relative mortality risk of 1.34 relative to those with products of 42 to 52 mg2/dL2. The relative mortality risk by log parathyroid hormone (PTH) level was elevated for patients with higher levels, but the mortality risk associated with hyperphosphatemia was independent of PTH. For hemodialysis patients who have been receiving dialysis for at least 1 year, we conclude that a large percentage have a serum phosphorus level above 6.5 mg/dL and that this places them at increased risk of death. This increased risk is independent of PTH. The mechanism(s) responsible for death is unknown, but may be related to an abnormally high Ca x PO4 product. Although mechanisms are not clearly established, this study supports the need for vigorous control of hyperphosphatemia to improve patient survival.

Crossover comparison of rizatriptan 5 mg and 10 mg versus sumatriptan 25 mg and 50 mg in migraine. Rizatriptan Protocol 046 Study Group.

Rizatriptan is a selective 5-HT1B/1D receptor agonist with rapid oral absorption and early onset of action in the acute treatment of migraine. This double-blind, placebo-controlled, crossover study compared rizatriptan 5 mg versus sumatriptan 25 mg, and rizatriptan 10 mg versus sumatriptan 50 mg. A total of 1329 patients were allocated to one of five groups for treatment of two attacks: rizatriptan 5 mg/sumatriptan 25 mg; sumatriptan 25 mg/rizatriptan 5 mg; rizatriptan 10 mg/sumatriptan 50 mg; sumatriptan 50 mg/rizatriptan 10 mg; placebo/placebo. For each attack, patients rated headache severity, presence of associated symptoms, and functional disability prior to dosing and at intervals through 4 hours thereafter. Patients also rated their satisfaction with medication. Rizatriptan 5 mg and 10 mg provided faster relief of headache pain and greater relief of migraine symptoms than the 25-mg and 50-mg doses of sumatriptan, respectively. The response to rizatriptan was better than sumatriptan on additional measures including functional disability and satisfaction with medication. All active treatments were highly effective compared to placebo and acted as early as 30 minutes after dosing. All active treatments were well-tolerated and showed comparable safety profiles.

Oral rizatriptan versus oral sumatriptan: a direct comparative study in the acute treatment of migraine. Rizatriptan 030 Study Group.

Rizatriptan is a potent, oral, 5-HT1B/1D agonist with more rapid absorption and higher bioavailability than oral sumatriptan. It was postulated that this would result in more rapid onset of effect. This randomized, double-blind, triple-dummy, parallel-groups study compared rizatriptan 5 mg, rizatriptan 10 mg, sumatriptan 100 mg, and placebo in 1268 outpatients treating a single migraine attack. Headache relief rates after rizatriptan 10 mg were consistently higher than sumatriptan at all time points up to 2 hours, with significance at 1 hour (37% versus 28%, P = 0.010). All active agents were significantly superior to placebo with regard to headache relief and pain freedom at 2 hours (P < or = 0.001). The primary efficacy endpoint of time to pain relief through 2 hours demonstrated that, after adjustment for age imbalance, rizatriptan 10 mg had earlier onset than sumatriptan 100 mg (P = 0.032; hazard ratio 1.21). Rizatriptan 10 mg was also superior to sumatriptan on pain-free response (P = 0.032), reduction in functional disability (P = 0.015), and relief of nausea at 2 hours (P = 0.010). Significantly fewer drug-related clinical adverse events were reported after rizatriptan 10 mg (33%, P = 0.014) compared with sumatriptan 100 mg (41%). We conclude that rizatriptan 10 mg has a rapid onset of action and relieves headache and associated symptoms more effectively than sumatriptan 100 mg.

Efficacy and safety of rizatriptan versus standard care during long-term treatment for migraine. Rizatriptan Multicenter Study Groups.

Rizatriptan is a novel, selective 5-HT1B/1D receptor agonist with a rapid onset of action after oral dosing for the acute treatment of migraine. We conducted a long-term (up to 1 year), multicenter, randomized study in 1831 patients treating more than 46,000 attacks to compare the efficacy and tolerability of rizatriptan 5 mg and 10 mg to standard care medications routinely used for the acute treatment of migraine attacks. Both doses of rizatriptan were highly effective, without evidence of tachyphylaxis. Rizatriptan 10 mg was consistently superior (P < 0.05), both to the 5-mg dose and to standard care, in providing relief in 90% of attacks, with 50% pain-free by 2 hours after dosing. The most common dose-related adverse events were nausea, somnolence, and asthenia/fatigue. Based on this large, multicenter, long-term trial, rizatriptan is an important new oral agent for the acute treatment of migraine.

Improvement in migraine-specific quality of life in a clinical trial of rizatriptan.

A validated migraine-specific questionnaire (24-h Migraine Quality of Life Questionnaire: 24-h MQoLQ) was used to assess the impact of migraine and migraine therapy on health-related quality of life during an acute migraine attack. Male and female migraineurs aged 18-55 years were randomized to placebo (n=41), rizatriptan 2.5 mg (n=47), 5 mg (n=74), or 10 mg (n=85) in a triple-blind, placebo-controlled clinical trial. Rizatriptan 5 mg and 10 mg were significantly more efficacious than placebo on pain relief and functional disability. After accounting for multiple comparisons to placebo, rizatriptan 10 mg showed significantly better responses compared to placebo on three of five domains of 24-h MQoLQ (social functioning, migraine symptoms, and feelings/concerns). The O'Brien's Rank Sum Test statistic showed a statistically significant overall difference on the 24-h MQoLQ between the 10 mg rizatriptan and placebo groups (p=0.005) and for the overall dose trend (p< or =0.001).

A multiple-dose safety trial of eptastigmine in Alzheimer's disease, with pharmacodynamic observations of red blood cell cholinesterase.

A placebo-controlled multiple dose study was conducted to evaluate the safety, tolerability, and pharmacodynamics of multiple dose levels of eptastigmine in 25 patients with probable Alzheimer's disease (AD). Twenty patients (12 M, 8 F; mean age 74, range 57-84) were randomized to receive 12mg (N = 3), 20mg (N = 6), 28mg (N = 6) or placebo (N = 5) tid on a double-blind basis for 14 days, followed by seven days of single blind placebo, in successively rising dose groups. All patients completed the study without intolerable or severe adverse events. All doses significantly (p < 0.001) reduced peak and trough RBC cholinesterase (AChE) activity as compared to baseline. Percent inhibition for Day 14 peak and trough RBC AChE peak and trough values, respectively, appeared proportional to dose: 18% and 21% (12mg); 36% and 35% (20mg); 40% and 44% (28mg). In order to determine the maximum tolerated dose of eptastigmine, an additional single-blind study was performed in five patients (2 M, 3 F; mean age 78, range 72-80) utilizing a rising dose schedule of eptastigmine (N = 4) or placebo (N = 1), starting with the previously tolerated 28mg tid dose and increasing by 4mg tid up to a potential maximum of 56mg tid. Dose-limiting adverse events occurred requiring discontinuation of medication in one patient at 48mg tid and two patients at 52mg tid; RBC AChE inhibition was proportional to dose, with peak values up to 70% inhibition at 48mg tid. The maximum tolerated dose of 48mg tid was identified as a basis for potential Phase II multicenter efficacy trials.

Controlled release levodopa/carbidopa 25/100 (Sinemet CR 25/100): pharmacokinetics and clinical efficacy in untreated parkinsonian patients.

The pharmacokinetics of the clinically determined optimal dose of controlled release levodopa/carbidopa 25/100 (Sinemet CR 25/100) after 12 weeks of therapy was studied in nine parkinsonian patients without prior exposure to levodopa. The pharmacokinetics of single oral doses of controlled release levodopa/carbidopa 25/100 and 50/200 were also compared. As predicted from the plasma half-life (1.7 +/- 0.3 h) and confirmed by morning trough levels, levodopa did not accumulate when controlled released levodopa/carbidopa 25/100 was administered twice daily. The absorption and bioavailability of CR 25/100 are minimally greater than CR 50/200. Controlled released levodopa/carbidopa 25/100 levodopa plasma levels peak slightly faster than controlled release levodopa/carbidopa 50/200.