Model-Informed Development of Sotalol Loading and Dose Escalation Employing an Intravenous Infusion.

BACKGROUND: Sotalol is often employed to prevent recurrence of symptomatic atrial flutter/atrial fibrillation. Because sotalol can prolong the QT interval excessively causing ventricular arrhythmias, a 3-day in-hospital loading or dose escalation period is mandated with oral administration in the product label for patient safety. In patients with normal renal function, 3 days (five oral doses) are required to obtain steady state maximum sotalol concentration, which results in maximum QT prolongation. The aim of this study is to develop an intravenous to oral loading regime for sotalol therapy that reduces the 3-day in-hospital initiation or dose escalation with oral administration to 1 day without compromising patient safety. METHODS: Using model-informed drug development techniques, simulations were developed for initiation and dose escalation of sotalol therapy by employing an intravenous loading dose followed by oral sotalol administrations. RESULTS: In patients with normal renal function, an initial 1-h loading dose of intravenous sotalol followed by two oral doses in 24 h has been developed permitting attainment of three maximum serum concentrations reflecting maximum QT prolongation in a 1-day observation period. Dosing regimens for patients with impaired renal function are also developed. CONCLUSIONS: In patients with normal renal function, using an intravenous loading dose followed by oral administrations permits safe initiation or dose escalation of sotalol in 1 day instead of the 3-day dosing regimen with oral administration.

Inhibition of Human Ether-A-Go-Go-Related Gene (hERG) Potassium Current by the Novel Sotalol Analogue, Soestalol.

The clinical utility of intravenous sotalol is limited due to an extended half-life combined with the potential to generate life-threatening arrhythmias. The authors developed a novel sotalol analogue, soestalol, with an ester linkage introduced to the molecule to shorten half-life. Their hypothesis was that soestalol, but not the acid metabolite, would inhibit the hERG potassium current. Whole-cell, voltage-clamp experiments were performed on cells expressing hERG. Soestalol inhibited outward IhERG tail current density in a manner similar to conventional sotalol. Additionally, soestalol right shifted the voltage dependence of activation. These results warrant further assessment of soestalol as a short-acting, Class III antiarrhythmic drug.

Intravenous Sotalol for the Treatment of Ventricular Dysrhythmias in an Infant on Extracorporeal Membrane Oxygenation.

Sotalol is a class III anti-arrhythmic agent with beta receptor blocking properties. Intravenous (IV) sotalol may be useful to treat refractory atrial and ventricular arrhythmias. A report on the efficacy and safety of IV sotalol in an infant on extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT), who developed refractory ventricular arrhythmias following surgery for congenital heart disease. A 10-day old infant with severe pulmonary valve stenosis underwent surgical pulmonary valvectomy and enlargement of the main pulmonary artery. Post-operatively, the patient developed hemodynamically significant accelerated idioventricular rhythm which was not responsive to a combination of amiodarone, lidocaine, and procainamide leading to 2 cardiac arrest events and placement on ECMO. The amiodarone infusion was uptitrated to 20 mcg/kg/min, but episodes of the hemodynamically compromising arrhythmia continued. Amiodarone was discontinued and IV sotalol was initiated at 42 mg/m2/day, divided to 3 doses, and administered every 8 h, which completely suppressed the arrhythmia. The initial sotalol dose was calculated based on a daily dose of 90 mg/m2 and reduced by an age-related factor as recommended by the FDA approved prescribing information. Subsequently, acute kidney injury requiring CRRT developed. The patient remained on IV sotalol for 3 weeks and then transitioned to oral sotalol. The oral dose was increased to 44 mg/m2/day (3.5 mg every 8 h) to account for the difference in bioavailability between the IV and oral formulations. Serial sotalol levels during IV and PO therapy remained therapeutic on ECMO and CRRT. The patient maintained normal sinus rhythm on sotalol without adverse events. IV sotalol in the setting of ECMO and CRRT was safe and effective in controlling refractory hemodynamically compromising accelerated idioventricular rhythm unresponsive to amiodarone.

Efficacy of Intravenous and Oral Sotalol in Pharmacologic Conversion of Atrial Fibrillation: A Systematic Review and Meta-Analysis.

OBJECTIVES: The role of sotalol is well established for the maintenance of sinus rhythm after successful conversion of atrial fibrillation (AF). However, its role in pharmacologic conversion of AF is poorly defined. The purpose of this study is to compare the efficacy of sotalol to that of other antiarrhythmic agents for AF conversion. METHODS: Standard methods of meta-analysis were employed. Full-text publications of clinical trials in English that compared the efficacy of sotalol to that of other antiarrhythmics or placebo/no treatment were eligible for inclusion. RESULTS: A systematic review revealed 10 eligible publications. Sotalol was superior to placebo and/or no antiarrhythmic therapy in AF conversion, with a relative success of 24 (95% CI 4.7-119, p < 0.001). Sotalol was not significantly different from class IA antiarrhythmic drugs. Similarly, sotalol was not different from class IC antiarrhythmic drugs or amiodarone in terms of conversion efficacy. In one study, sotalol was less effective than high-dose ibutilide (2 mg), with a relative success of 0.248 (95% CI 0.128-0.481, p < 0.001). Ibutilide caused more proarrhythmia. CONCLUSIONS: Sotalol is as effective as class IA and class IC antiarrhythmic agents, and it is also as effective as amiodarone for pharmacologic conversion of AF. Only ibutilide at a high dose showed a greater conversion rate of AF.

Evaluation of the Effects of Different Energy Drinks and Coffee on Endothelial Function.

Endothelial function plays an important role in circulatory physiology. There has been differing reports on the effect of energy drink on endothelial function. We set out to evaluate the effect of 3 energy drinks and coffee on endothelial function. Endothelial function was evaluated in healthy volunteers using a device that uses digital peripheral arterial tonometry measuring endothelial function as the reactive hyperemia index (RHI). Six volunteers (25 ± 7 years) received energy drink in a random order at least 2 days apart. Drinks studied were 250 ml "Red Bull" containing 80 mg caffeine, 57 ml "5-hour Energy" containing 230 mg caffeine, and a can of 355 ml "NOS" energy drink containing 120 mg caffeine. Sixteen volunteers (25 ± 5 years) received a cup of 473 ml coffee containing 240 mg caffeine. Studies were performed before drink (baseline) at 1.5 and 4 hours after drink. Two of the energy drinks (Red Bull and 5-hour Energy) significantly improved endothelial function at 4 hours after drink, whereas 1 energy drink (NOS) and coffee did not change endothelial function significantly. RHI increased by 82 ± 129% (p = 0.028) and 63 ± 37% (p = 0.027) after 5-hour Energy and Red Bull, respectively. The RHI changed after NOS by 2 ± 30% (p = 1.000) and by 7 ± 30% (p = 1.000) after coffee. In conclusion, some energy drinks appear to significantly improve endothelial function. Caffeine does not appear to be the component responsible for these differences.

Retrospective Evaluation on the Analgesic Activities of 2 Compounded Topical Creams and Voltaren Gel in Chronic Noncancer Pain.

Pharmacologic treatment of chronic pain is challenging. Oral therapy may require multiple medications; each has side effects, dose limitations, and limited efficacy. Compounded topical formulations have evolved as potential treatment options. The objective of this study was to evaluate the efficacy of 2 compounded topical creams, "Cream I" and "Cream II," in patients with chronic extremity, joint, musculoskeletal, neuropathic, or other chronic topical pain conditions and compare their efficacy with Voltaren gel. The primary efficacy outcome was the change in visual numeric pain intensity score from pretreatment to posttreatment. The Cream I contained Flurbiprofen (20%), Tramadol (5%), Clonidine (0.2%), Cyclobenzaprine (4%), and Bupivacaine (3%). The Cream II contained Flurbiprofen (20%), Baclofen (2%), Clonidine (0.2%), Gabapentin (10%), and Lidocaine (5%). The Voltaren gel contained 1% diclofenac sodium. A total of 2177 patients were evaluated, 826 males and 1351 females. During their medical treatment, 1141 patients received Cream I, 527 patients received Cream II, and 509 patients received Voltaren gel. After treatment, the pain intensity score decreased by 3.11 ± 1.65 (37%) with Cream I (from 8.44 ± 1.19 to 5.33 ± 2.0, P < 0.001), by 2.93 ± 1.58 (35%) with Cream II (from 8.42 ± 1.27 to 5.50 ± 1.96, P < 0.001), and by 1.49 ± 0.73 (19%) with Voltaren gel (from 7.93 ± 0.81 to 6.44 ± 1.14, P < 0.001). Cream I and Cream II did not differ significantly in efficacy, and both were significantly more effective than Voltaren gel (P < 0.001). It is concluded that Voltaren gel had less efficacy than the compounded creams, which were effective and provided pain relief in the majority of the patients studied.

A Rapid Method to Evaluate Cardiac Repolarization Changes: The Effect of Two Coffee Strengths on the QT Interval.

OBJECTIVES: To assess the effect of coffee on ventricular repolarization as measured by an electrocardiogram. METHODS: Fifty-four healthy volunteers (34 males and 20 females, age 23 ± 5 years) received 1 cup of coffee (caffeine content 120 mg) and 11 participants received 2 cups. Blood pressure and heart rate were measured prior to coffee and every hour thereafter for 5 h. A 12-lead digital Holter recorded continuously, and RR, QT, and QTc intervals were obtained every 30 min. RESULTS: Following coffee, RR increased from 802 ± 102 to 873 ± 126 ms (p = 0.001), QT increased from 359 ± 26 to 367 ± 27 ms at 1.5 h (p = 0.047), and QTc decreased from 387 ± 21 to 381 ± 23 ms at 30 min (p = 0.001), with no changes noted at other time points. Caffeine users and caffeine-naive subjects did not differ in QTc effects (p = 0.971). Females had longer QTc at each time point than males (p = 0.037), but neither had QTc prolongation following coffee. The heart rate decreased from 73 ± 9 to 69 ± 11 bpm at 1 h (p = 0.018), and no significant changes in blood pressure were noted. The effects of 1 or 2 cups of coffee did not differ in terms of QTc (p = 0.663), heart rate (p = 0.161), diastolic (p = 0.250), or systolic blood pressure (p = 0.168). CONCLUSION: Neither 1 nor 2 cups of coffee increased ventricular repolarization.

Retrospective Study on the Analgesic Activity of a Topical (TT-CTAC) Cream in Patients With Diabetic Neuropathy and Other Chronic Pain Conditions.

Treatment of chronic pain in diabetic neuropathy or neuropathic pain of other origins is challenging. Compounded topical formulations have evolved as potential treatment options. The objective of this retrospective study was to evaluate the efficacy of a compounded topical cream (Transdermal Therapeutics). Two versions of TT-CTAC cream were evaluated: cream 6B and cream 7B. Both creams contain ketamine (10%), baclofen (2%), gabapentin (6%), amitriptyline (4%), bupivacaine (2%), and clonidine (0.2%). Additionally, one cream (7B) contains nifedipine (2%). The primary efficacy outcome was the change in numeric pain intensity score from pretreatment to posttreatment. Secondary outcomes were qualitative grading (excellent, good, poor, or no effect), reduction in oral medication, and avoiding referral to a pain specialist. Information on 283 patients was evaluated, 205 received the 7B and 78 received 6B creams. The pain score decreased by 2.4 ± 2.4 (35%) with the 6B cream (from 7.8 ± 1.6 to 5.4 ± 2.0, P < 0.001) and by 3.0 ± 2.4 (40%) with the 7B cream (from 7.5 ± 1.7 to 4.5 ± 2.2, P < 0.001). Excellent or good effects were reported in 82% of the patients in the 6B and in 70% in the 7B groups. Reduction in oral pain medication was seen in 35% of the patients in the 7B and in 20% in the 6B groups. In the opinion of the treating physicians, the cream therapy caused the avoidance of a pain specialist referral in 53% of the patients in the 6B and in 39% in the 7B groups. The creams were equally effective in diabetic neuropathy, neuropathic pain, or other chronic pain states. We conclude that both creams provided excellent pain relief in the majority of the patients studied and may be a useful modality for pain therapy.

Assessment of cardiovascular and noncardiovascular medical device recalls.

Medical device recalls have called attention to the device approval process in the United States. The premarket approval (PMA) process requires clinical trials to evaluate safety and effectiveness, whereas the expedited 510(k) process does not. The 510(k) process has been considered a source of increased recalls. This study aimed to assess the relative safety of medical device approval pathways based on the numbers of approvals and recalls. Data on recalls in the United States from January 2005 to December 2012 were collected from the Food and Drug Administration Web site. Over 8 years, 30,002 devices were approved, 5,728 by PMA (19%) and 24,274 (81%) by 510(k). There were 249 recalls due to serious risks, 0.45% of PMA approvals, and 0.92% of 510(k)-cleared devices, p <0.001. Over 1/2 of the recalls were during the first 2 years on the market. Percentage of recalled PMA devices was unchanged over the 8 years, whereas 510(k) recalls increased in 2010 to 2012 (from 0.65% to 1.39%, p <0.001). Cardiovascular devices represent the largest class of recalls (27%). The proportions of recalled PMA and 510(k) cardiovascular devices were the same as for all medical devices until 2011, but 510(k) recalls dramatically decreased in 2012 to the lowest recall rate seen (0.73%). In conclusion, recall rates were the same for 510(k)- and PMA-approved devices in 2005 to 2009 and increased for 510(k) devices subsequently. Modifying the 510(k) process with more rigorous performance testing, a conditional 2-year approval and a mandatory registry may be an approach to reduce recalls.