Dahlia Garza

Efficacy and Safety of Varenicline for Smoking Cessation in Patients With Cardiovascular Disease A Randomized Trial

Background— Smoking cessation is a key component of secondary cardiovascular disease prevention. Varenicline, a partial &agr;4&bgr;2 nicotinic acetylcholine receptor agonist, is effective for smoking cessation in healthy smokers, but its efficacy and safety in smokers with cardiovascular disease are unknown. Methods and Results— A multicenter, randomized, double-blind, placebo-controlled trial compared the efficacy and safety of varenicline with placebo for smoking cessation in 714 smokers with stable cardiovascular disease. Participants received varenicline (1 mg twice daily) or placebo, along with smoking-cessation counseling, for 12 weeks. Follow-up lasted 52 weeks. The primary end point was carbon monoxide–confirmed continuous abstinence rate for weeks 9 through 12 (last 4 weeks of treatment). The continuous abstinence rate was higher for varenicline than placebo during weeks 9 through 12 (47.0% versus 13.9%; odds ratio, 6.11; 95% confidence interval [CI], 4.18 to 8.93) and weeks 9 through 52 (19.2% versus 7.2%; odds ratio, 3.14; 95% CI, 1.93 to 5.11). The varenicline and placebo groups did not differ significantly in cardiovascular mortality (0.3% versus 0.6%; difference, −0.3%; 95% CI, −1.3 to 0.7), all-cause mortality (0.6% versus 1.4%; difference, −0.8%; 95% CI, −2.3 to 0.6), cardiovascular events (7.1% versus 5.7%; difference, 1.4%; 95% CI, −2.3 to 5.0), or serious adverse events (6.5% and 6.0%; difference, 0.5%; 95% CI, −3.1 to 4.1). As a result of adverse events, 9.6% of varenicline and 4.3% of placebo participants discontinued study drug. Conclusions— Varenicline is effective for smoking cessation in smokers with cardiovascular disease. It was well tolerated and did not increase cardiovascular events or mortality; however, trial size and duration limit definitive conclusions about safety. Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov/ct2/show/NCT00282984. Unique identifier: NCT00282984.

Patiromer in Patients with Kidney Disease and Hyperkalemia Receiving RAAS Inhibitors

BACKGROUND Hyperkalemia increases the risk of death and limits the use of inhibitors of the renin-angiotensin-aldosterone system (RAAS) in high-risk patients. We assessed the safety and efficacy of patiromer, a nonabsorbed potassium binder, in a multicenter, prospective trial. METHODS Patients with chronic kidney disease who were receiving RAAS inhibitors and who had serum potassium levels of 5.1 to less than 6.5 mmol per liter received patiromer (at an initial dose of 4.2 g or 8.4 g twice a day) for 4 weeks (initial treatment phase); the primary efficacy end point was the mean change in the serum potassium level from baseline to week 4. Eligible patients at the end of week 4 (those with a baseline potassium level of 5.5 to <6.5 mmol per liter in whom the level decreased to 3.8 to <5.1 mmol per liter) entered an 8-week randomized withdrawal phase in which they were randomly assigned to continue patiromer or switch to placebo; the primary efficacy end point was the between-group difference in the median change in the serum potassium level over the first 4 weeks of that phase. RESULTS In the initial treatment phase, among 237 patients receiving patiromer who had at least one potassium measurement at a scheduled visit after day 3, the mean (±SE) change in the serum potassium level was -1.01±0.03 mmol per liter (P<0.001). At week 4, 76% (95% confidence interval, 70 to 81) of the patients had reached the target potassium level (3.8 to <5.1 mmol per liter). Subsequently, 107 patients were randomly assigned to patiromer (55 patients) or placebo (52 patients) for the randomized withdrawal phase. The median increase in the potassium level from baseline of that phase was greater with placebo than with patiromer (P<0.001); a recurrence of hyperkalemia (potassium level, ≥5.5 mmol per liter) occurred in 60% of the patients in the placebo group as compared with 15% in the patiromer group through week 8 (P<0.001). Mild-to-moderate constipation was the most common adverse event (in 11% of the patients); hypokalemia occurred in 3%. CONCLUSIONS In patients with chronic kidney disease who were receiving RAAS inhibitors and who had hyperkalemia, patiromer treatment was associated with a decrease in serum potassium levels and, as compared with placebo, a reduction in the recurrence of hyperkalemia. (Funded by Relypsa; OPAL-HK ClinicalTrials.gov number, NCT01810939.).

Effect of Patiromer on Serum Potassium Level in Patients With Hyperkalemia and Diabetic Kidney Disease: The AMETHYST-DN Randomized Clinical Trial

IMPORTANCE Hyperkalemia is a potentially life-threatening condition predominantly seen in patients treated with renin-angiotensin-aldosterone system (RAAS) inhibitors with stage 3 or greater chronic kidney disease (CKD) who may also have diabetes, heart failure, or both. OBJECTIVES To select starting doses for a phase 3 study and to evaluate the long-term safety and efficacy of a potassium-binding polymer, patiromer, in outpatients with hyperkalemia. DESIGN, SETTING, AND PARTICIPANTS Phase 2, multicenter, open-label, dose-ranging, randomized clinical trial (AMETHYST-DN), conducted at 48 sites in Europe from June 2011 to June 2013 evaluating patiromer in 306 outpatients with type 2 diabetes (estimated glomerular filtration rate, 15 to <60 mL/min/1.73 m2 and serum potassium level >5.0 mEq/L). All patients received RAAS inhibitors prior to and during study treatment. INTERVENTIONS Patients were stratified by baseline serum potassium level into mild or moderate hyperkalemia groups and received 1 of 3 randomized starting doses of patiromer (4.2 g [n = 74], 8.4 g [n = 74], or 12.6 g [n = 74] twice daily [mild hyperkalemia] or 8.4 g [n = 26], 12.6 g [n = 28], or 16.8 g [n = 30] twice daily [moderate hyperkalemia]). Patiromer was titrated to achieve and maintain serum potassium level 5.0 mEq/L or lower. MAIN OUTCOMES AND MEASURES The primary efficacy end point was mean change in serum potassium level from baseline to week 4 or prior to initiation of dose titration. The primary safety end point was adverse events through 52 weeks. Secondary efficacy end points included mean change in serum potassium level through 52 weeks. RESULTS A total of 306 patients were randomized. The least squares mean reduction from baseline in serum potassium level at week 4 or time of first dose titration in patients with mild hyperkalemia was 0.35 (95% CI, 0.22-0.48) mEq/L for the 4.2 g twice daily starting-dose group, 0.51 (95% CI, 0.38-0.64) mEq/L for the 8.4 g twice daily starting-dose group, and 0.55 (95% CI, 0.42-0.68) mEq/L for the 12.6 g twice daily starting-dose group. In those with moderate hyperkalemia, the reduction was 0.87 (95% CI, 0.60-1.14) mEq/L for the 8.4 g twice daily starting-dose group, 0.97 (95% CI, 0.70-1.23) mEq/L for the 12.6 g twice daily starting-dose group, and 0.92 (95% CI, 0.67-1.17) mEq/L for the 16.8 g twice daily starting-dose group (P < .001 for all changes vs baseline by hyperkalemia starting-dose groups within strata). From week 4 through week 52, statistically significant mean decreases in serum potassium levels were observed at each monthly point in patients with mild and moderate hyperkalemia. Over the 52 weeks, hypomagnesemia (7.2%) was the most common treatment-related adverse event, mild to moderate constipation (6.3%) was the most common gastrointestinal adverse event, and hypokalemia (<3.5 mEq/L) occurred in 5.6% of patients. CONCLUSIONS AND RELEVANCE Among patients with hyperkalemia and diabetic kidney disease, patiromer starting doses of 4.2 to 16.8 g twice daily resulted in statistically significant decreases in serum potassium level after 4 weeks of treatment, lasting through 52 weeks. TRIAL REGISTRATION clinicaltrials.gov Identifier:NCT01371747.

Varenicline for smoking cessation: A placebo-controlled, randomized study

Background and objective:  Varenicline tartrate, a novel, selective, nicotinic acetylcholine receptor partial agonist, has been developed specifically as a smoking cessation drug. This study evaluated the efficacy of a standard regimen of varenicline compared with placebo for smoking cessation in 333 subjects in China, Singapore and Thailand.

Effect of patiromer on reducing serum potassium and preventing recurrent hyperkalaemia in patients with heart failure and chronic kidney disease on RAAS inhibitors

We evaluated the effects of patiromer, a potassium (K+)‐binding polymer, in a pre‐specified analysis of hyperkalaemic patients with heart failure (HF) in the OPAL‐HK trial.

Patiromer induces rapid and sustained potassium lowering in patients with chronic kidney disease and hyperkalemia

Patients with chronic kidney disease (CKD) have a high risk of hyperkalemia, which increases mortality and can lead to renin–angiotensin–aldosterone system inhibitor (RAASi) dose reduction or discontinuation. Patiromer, a nonabsorbed potassium binder, has been shown to normalize serum potassium in patients with CKD and hyperkalemia on RAASi. Here, patiromers onset of action was determined in patients with CKD and hyperkalemia taking at least one RAASi. After a 3-day potassium- and sodium-restricted diet in an inpatient research unit, those with sustained hyperkalemia (serum potassium 5.5 – under 6.5 mEq/l) received patiromer 8.4 g/dose with morning and evening meals for a total of four doses. Serum potassium was assessed at baseline (0 h), 4 h postdose, then every 2–4 h to 48 h, at 58 h, and during outpatient follow-up. Mean baseline serum potassium was 5.93 mEq/l and was significantly reduced by 7 h after the first dose and at all subsequent times through 48 h. Significantly, mean serum potassium under 5.5 mEq/l was achieved within 20 h. At 48 h (14 h after last dose), there was a significant mean reduction of 0.75 mEq/l. Serum potassium did not increase before the next dose or for 24 h after the last dose. Patiromer was well tolerated, without serious adverse events and no withdrawals. The most common gastrointestinal adverse event was mild constipation in two patients. No hypokalemia (serum potassium under 3.5 mEq/l) was observed. Thus, patiromer induced an early and sustained reduction in serum potassium and was well tolerated in patients with CKD and sustained hyperkalemia on RAASis.

Prognosis of a Normal Positron Emission Tomography 82Rb Myocardial Perfusion Imaging Study in Women with No History of Coronary Disease

Objectives: Myocardial perfusion imaging (MPI) with positron emission tomography (PET) has advantages over single-photon emission computerized tomography, particularly for women. This investigation was undertaken to define the prognosis of a normal stress PET MPI study in women. Methods:The cohort comprised 457 women evaluated for suspected coronary artery disease (CAD) who had normal pharmacologic stress 82Rb PET MPI. No patient had clinically evident CAD. Kaplan-Meier estimates were used to determine death and initial nonfatal cardiac event rates over 7 years. Log rank tests were used to assess the relationship between baseline cardiac risk and events during follow-up, and to contrast survival in the cohort with age- and gender-matched US census comparators. Results: During follow-up, there were 11 deaths (all nonischemic), 3 nonfatal myocardial infarctions, 3 percutaneous coronary interventions and 1 coronary artery bypass operation. Average risks of death and initial nonfatal cardiac events were 0.72 and 0.47% per year, respectively. Cardiac events were associated with a history of diabetes (p < 0.0003) and a family history of CAD (p < 0.05). Conclusion: A normal cardiac PET study is associated with a very low rate of future cardiac events. Women with diabetes and a strong family history of CAD are more likely to sustain events and require close surveillance for the development of coronary disease.

Effectiveness of patiromer in the treatment of hyperkalemia in chronic kidney disease patients with hypertension on diuretics.

Objective: Recurrent hyperkalemia frequently limits use of renin–angiotensin–aldosterone system inhibitors (RAASi) in chronic kidney disease (CKD) patients with hypertension, diabetes, and/or heart failure. Patiromer is a sodium-free, nonabsorbed potassium (K+)-binding polymer approved by the US Food and Drug Administration for the treatment of hyperkalemia. This post-hoc analysis of OPAL-HK examined the effectiveness and safety of patiromer in reducing serum K+ in hyperkalemic CKD patients on RAASi, with hypertension, receiving diuretic therapy versus those not on diuretics. Methods: Depending on the degree of hyperkalemia at baseline, CKD patients with serum K+ from 5.1 to less than 6.5 mmol/l on RAASi (n = 243) were assigned to a patiromer of total dose 8.4 or 16.8 g, divided twice daily. Changes in serum K+, and tolerability and safety were assessed over 4 weeks in patients on and not on diuretics. Results: At baseline, 132 patients used diuretics and 111 were not on diuretics, mean age was 64.3 and 64.0 years, respectively, and 63 and 51% were men. Similar reductions in serum K+ were seen over 4 weeks in both subgroups. At week 4, serum K+ fell by −0.95 ± 0.04 mmol/l with any diuretic and −1.04 ± 0.05 mmol/l with no diuretic. Patiromer was well tolerated, with mild-to-moderate constipation reported as the most common adverse event (7.6 and 14.4% of patients on any diuretic or no diuretic, respectively). Hypokalemia (s-K+ <3.5 mEq/l) was reported in 2.3% of patients on any diuretic and in 3.7% not on diuretics. Conclusion: The serum K+-lowering efficacy and safety profile of patiromer in hyperkalemia patients with CKD was not compromised by diuretic therapy.

Evaluation of the Potential for Drug Interactions With Patiromer in Healthy Volunteers

Introduction: Patiromer is a potassium-binding polymer that is not systemically absorbed; however, it may bind coadministered oral drugs in the gastrointestinal tract, potentially reducing their absorption. Methods: Twelve randomized, open-label, 3-period, 3-sequence crossover studies were conducted in healthy volunteers to evaluate the effect of patiromer (perpetrator drug) on absorption and single-dose pharmacokinetics (PK) of drugs (victims) that might be commonly used with patiromer. Subjects received victim drug alone, victim drug administered together with patiromer 25.2 g (highest approved dose), and victim drug administered 3 hours before patiromer 25.2 g. The primary PK endpoints were area under the curve (AUC), extrapolated to infinity (AUC0-∞), and maximum concentration (C max). Results were reported as 90% confidence intervals (CIs) about the geometric mean AUC0-∞ and C max ratios with prespecified equivalence limits of 80% to 125%. Results: Overall, 370 subjects were enrolled, with 365 receiving ≥1 dose of patiromer; 351 subjects completed the studies and all required treatments. When coadministered with patiromer, the 90% CIs for AUC0-∞ remained within 80% to 125% for 9 drugs (amlodipine, cinacalcet, clopidogrel, furosemide, lithium, metoprolol, trimethoprim, verapamil, and warfarin). The AUC0-∞ point estimate ratios for levothyroxine and metformin with patiromer coadministration were ≥80%, with the lower bounds of the 90% CIs at 76.8% and 72.8%, respectively. For ciprofloxacin, the point estimate for AUC0-∞ was 71.5% (90% CI: 65.3-78.4). For 8 of 12 drugs, point estimates for C max were ≥80% with patiromer coadministration; for ciprofloxacin, clopidogrel, metformin, and metoprolol, the point estimates were <80%. When patiromer was administered 3 hours after each victim drug, the 90% CIs for AUC0-∞ and C max for each drug were within the prespecified 80% to 125% limits. Conclusion: For 9 of the 12 drugs coadministered with patiromer, there were no clinically significant drug–drug interactions. For 3 drugs (ciprofloxacin, levothyroxine, and metformin), a 3-hour separation between patiromer and their administration resulted in no clinically significant drug–drug interactions.

Evaluation of an individualized dose titration regimen of patiromer to prevent hyperkalaemia in patients with heart failure and chronic kidney disease

AIMS Hyperkalaemia risk precludes optimal renin-angiotensin-aldosterone system inhibitor use in patients with heart failure (HF), particularly those with chronic kidney disease (CKD). Patiromer is a sodium-free, non-absorbed potassium (K)-binding polymer approved for the treatment of hyperkalaemia. In PEARL-HF, patiromer 25.2 g (fixed dose) prevented hyperkalaemia in HF patients with or without CKD initiating spironolactone. The current study evaluated the effectiveness of a lower starting dose of patiromer (16.4 g/day) followed by individualized titration in preventing hyperkalaemia and hypokalaemia when initiating spironolactone. METHODS AND RESULTS This open-label 8-week study enrolled 63 patients with CKD, serum K4.3-5.1 mEq/L, and chronic HF, who, based on investigator opinion, should receive spironolactone. Eligible patients started spironolactone 25 mg/day and patiromer 16.8 g/day (divided into two doses), with patiromer titrated to maintain serum K4.0-5.1 mEq/L. Mean (standard deviation) serum Kwas 4.78 (0.51) mEq/L at baseline; weekly values were 4.48-4.70 mEq/L during treatment. Serum Kof 3.5-5.5 mEq/L at the end of study treatment (primary endpoint) was achieved by 57 (90.5%) patients; 53 (84.1%) had serum K4.0-5.1 mEq/L. One patient (1.6%) developed hypokalaemia, and two patients (3.2%) developed hypomagnesaemia. Spironolactone was increased to 50 mg/day in all patients; 43 (68%) patients required one or more patiromer dose titration. Adverse events (AEs) occurred in 36 (57.1%) patients, with a low rate of discontinuations [four (6.3%) patients]. The most common AE was mild to moderate abdominal discomfort [four (6.3%) patients]. CONCLUSIONS In this open-label study, patiromer 16.8 g/day followed by individualized titration maintained serum Kwithin the target range in the majority of patients with HF and CKD, all of whom were uptitrated to spironolactone 50 mg/day, patiromer was well tolerated, with a low incidence of hyperkalaemia, hypokalaemia, and hypomagnesaemia.