Use of an antiarrhythmic drug against acute selenium toxicity.

OBJECTIVE: Selenium is an essential trace element. But, selenium may have toxic effects in high doses. There are no proven antidotes or curative treatments for acut selenium toxicity. Treatment involves stopping the exposure and providing supportive care for symptoms. Therefore, it is necessary to find more effective substances in the treatment of selenium toxicity. The aim of this study was to increase the survival rate of animals by supporting the heart with amiodarone and to determine the effect of amiodarone on the pathological, hematological and biochemical parameters in acute selenium intoxication. METHODS: 64 Wistar-Albino rats were divided into four groups. Group I was given only distilled water, Group II was given 18 mg/kg dose of amiodarone, Group III was given 18 mg/kg amiodarone and 10 mg/kg sodium selenite and Group IV was given sodium selenite 10 mg/kg (LD50 dose)orally. RESULTS: 11 of the 16 animals in Group IV died within the first 48 h of drug administration. However, no deaths were observed in the rats in Group III. No hematological changes were observed. Biochemically, CK, CK-MB and LDH levels of Group IV were higher than the other groups on both the 2nd and 10th days. In Groups II and III, this serum level decreased, and vitamin B12 levels increased. In macroscopic inspections of the organs of Groups III and IV, slight paleness was detected. Histopathologically, degenerative changes in tissue were observed, especially in Group IV. CONCLUSION: This study shows that amiodarone application has a reducing effect on selenium toxicity. This was because amiodarone protected the heart by reducing CK and CK-MB levels and increased vitamin B12 levels, which play a role in the synthesis of S-adenosyl methionine that converts selenium into a nontoxic form.

Assessment of warfarin algorithms for hospitalized adults: searching for a safe dosing strategy.

This study evaluates three warfarin dosing algorithms (Kimmel, Dawson, High Dose ≥ 2.5 mg) for hospitalized older adults. A random selection of 250 patients with overshoots (INR ≥ 5 after 48 h of hospitalization) and 250 patients without overshoots were accessed from a database of 12,107 inpatients ≥ 65 years treated with chronic warfarin during hospitalization between January 1, 2014 and June 30, 2016. Algorithms were retrospectively applied to patients 2 days prior to overshoots in the overshoot group, and 2 days prior to the maximum INR reached after 48 h of hospitalization in the non-overshoot group. Patients were categorized as overdosed or not overdosed and compared using descriptive statistics. Logistic regression modeling determined predictors for overshoots. There was no significant difference between overdose and non-overdose groups for progressing to overshoots by the Kimmel (51.0% vs. 48.7%, p = 0.67) or Dawson (48.5 vs. 57.9%, p = 0.19) algorithms. The Low Dose Group (≤ 2.5 mg) was significantly more likely to experience an overshoot than the High Dose Group (56.6% vs. 45.5%, p = 0.04). The Low Dose Group was more likely to be older (81.4% vs. 71.1%, p = 0.02), female (63.5% vs. 49.8%, p = 0.02), weigh less (71.3 ± 21.9 vs. 79 ± 23.1, p = 0.002), and be prescribed amiodarone (16.6% vs. 8.1%, p = 0.01). While none of the algorithms predicted overshoots in logistic regression modeling, weight over 70 kg and black race remained protective. The High Dose Algorithm revealed that providers appropriately gave lower doses to patients at highest risk for warfarin sensitivity. Future studies are needed to investigate tools for inpatient warfarin dosing in older adults.

Amiodarone and acupuncture for cardiac arrhythmia: Study protocol for a systematic review.

BACKGROUND: Amiodarone and acupuncture (AA) are commonly used to treat cardiac arrhythmia (CA). The objective of this systematic review is to assess the efficacy and safety of AA for patients with CA. METHODS: Randomized controlled trials (RCTs) of AA for CC will be searched from 9 databases including PubMed, EMBASE, Cochrane Library, Web of Science, Scopus, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Information, and Wanfang Data from inception to February 1, 2019 without any limitations. Two reviewers will independently screen the relevant papers, extract data, and evaluate the risk of bias for each included study. RevMan 5.3 software will be used for meta-analysis. The primary outcome includes arrhythmic episodes (including time and frequency domain parameters). The secondary outcomes consist of health-related quality of life, oxygen saturation, and safety. RESULTS: The protocol of this proposed study will provide evidence to judge whether AA is an effective treatment for patients with CA. CONCLUSION: The findings of this proposed study will summarize the up-to-date evidence of AA for CA. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019120962.

Efficacy of topical chamomile on the incidence of phlebitis due to an amiodarone infusion in coronary care patients: a double-blind, randomized controlled trial.

BACKGROUND: Amiodarone is a useful antiarrhythmic drug. Phlebitis, caused by intravenous amiodarone, is common in patients in coronary care units (CCUs). OBJECTIVE: The aim of this study was to evaluate the effect of topical chamomile on the incidence of phlebitis due to the administration of an amiodarone infusion into the peripheral vein. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This was a randomized, double-blind clinical trial, conducted on 40 patients (n = 20 per group) in two groups-an intervention group (chamomile ointment) and a control group (lanoline, as a placebo), hospitalized in the CCUs and undergoing an amiodarone infusion into the peripheral vein over 24 h. Following the cannulation and commencement of the infusion, placebo or chamomile ointment was rubbed in, up to 10 cm superior to the catheter and repeated every eight hours for three days. The cannula site was then assessed based on the phlebitis checklist. MAIN OUTCOME MEASURES: The incidence and time of occurrence of phlebitis, relative risk, severity of phlebitis were the main outcome measures. RESULTS: Nineteen patients (19/20) in the control group had phlebitis on the first day of the study and one patient (20/20) on the second day. In the intervention group, phlebitis occurred in 13 cases (13/20) on the first day and another two (2/7) was found on the second day. The incidence of phlebitis was significantly different between two groups (P = 0.023). The cumulative incidence of phlebitis in the intervention group (15/20) is significantly later and lower than that in the control group (20/20) during two days (P = 0.008). Two patients in the intervention group did not develop phlebitis at all during the 3-day study. Also, the relative risk of phlebitis in the two groups was 0.68 (P = 0.008 5). A significant difference was not observed with regard to phlebitis severity in both groups. CONCLUSION: It seems that phlebitis occurred to a lesser extent and at a later time frame in the intervention group compared to control group. Topical chamomile may be effective in decreasing the incidence of phlebitis due to an amiodarone infusion. TRIAL REGISTRATION: This protocol was registered in the Iranian Registry of Clinical Trials (IRCT2014042017361N1).

Use of antiarrhythmic drugs during ablation of persistent atrial fibrillation: observations from a large single-centre cohort.

Catheter ablation of complex fractionated atrial electrograms (CFAE), also known as defragmentation ablation, may be considered for the treatment of persistent atrial fibrillation (AF) beyond pulmonary vein isolation (PVI). Concomitant antiarrhythmic drug (AAD) therapy is common, but the relevance of AAD administration and its optimal timing during ablation remain unclear. Therefore, we investigated the use and timing of AADs during defragmentation ablation and their possible implications for AF termination and ablation success in a large cohort of patients. Retrospectively, we included 200 consecutive patients (age: 61 ± 12 years, LA diameter: 47 ± 8 mm) with persistent AF (episode duration 47 ± 72 weeks) who underwent de novo ablation including CFAE ablation. In all patients, PVI was performed prior to CFAE ablation. The use and timing of AADs were registered. The follow-ups consisted of Holter ECGs and clinical visits. Termination of AF was achieved in 132 patients (66 %). Intraprocedural AADs were administered in 168/200 patients (84 %) 45 ± 27 min after completion of PVI. Amiodarone was used in the majority of the patients (160/168). The timing of AAD administration was predicted by the atrial fibrillation cycle length (AFCL). At follow-up, 88 patients (46 %) were free from atrial arrhythmia. Multivariate logistic regression analysis revealed that administration of AAD early after PVI, LA size, duration of AF history, sex and AFCL were predictors of AF termination. The administration of AAD and its timing were not predictive of outcome, and age was the sole independent predictor of AF recurrence. The administration of AAD during ablation was common in this large cohort of persistent AF patients. The choice to administer AAD therapy and the timing of the administration during ablation were influenced by AFCL, and these factors did not significantly influence the moderate single procedure success rate in this retrospective analysis.

Iodine-induced hyperthyroidism as combination of different etiologies: an overlooked entity in the elderly.

Iodine-induced thyrotoxicosis, which raises several diagnostic and therapeutical challenges, is often overlooked. Hyperthyroidism can induce atrial fibrillation, a harmful arrhythmia which can precipitate heart failure and cause stroke. We report the case of an elderly man who was diagnosed with tachyfibrillation secondary to hyperthyroidism. Thyroid hyperfunction was subsequently related both to previous amiodarone therapy (probably mixed form) and the recent use of iodinated contrast medium for computed tomography scan. Thyroid ultrasonography showed a plongeant multinodular goitre. After initial worsening, thyroid function improved slowly but progressively on high-dose thyreostatic therapy combined with steroid therapy; tachyfibrillation caused heart failure and a thrombus in the left atrium, and proved initially resistant to combined antiarrhythmic treatments. Progressive reduction in thyroid hormone levels, together with combined cardiologic therapies, controlled the heart rate, though atrial fibrillation persisted; anticoagulant therapy resolved the atrial thrombus. Alterations in thyroid function are common in amiodarone-treated patients, who therefore require regular hormonal checks. The different forms of amiodarone-induced thyrotoxicosis must be investigated, since they require different therapies, though mixed forms often occur. The superimposition of further iodine excess due to other causes may be catastrophic and cause severe cardiac problems in these patients.

[Hemoptysis during concomitant treatment with rivaroxaban and amiodarone in a patient with a history of pulmonary disease]. / Krwioplucie w trakcie jednoczesnego leczenia rywaroksabanem i amiodaronem u chorego z obciazonym wywiadem plucnym.

UNLABELLED: Rivaroxaban, a selective inhibitor of active factor X, is metabolized by cytochrom P450 3A4 (CYP3A4) and is a substrate for transporter protein--P-glycoprotein (P-gp). Amiodarone, an antiarrhytmic agent, is classified as moderate CYP3A4 and P-gp inhibitor. A CASE REPORT: A 75-year-old male, who underwent lobectomy for bronchiectasis many years ago, is presented. For one year the patient was treated with rivaroxaban (20 mg/d) due to venous thromboembolism and recurrent episodes of atrial fibrillation. Two weeks after amiodarone initiation (200 mg/d) hemoptysis occurred and computed tomography revealed unilateral pulmonary infiltrates with ground-glass opacities limited to the lower lobe of the left lung. The symptoms disappeared following discontinuation of the two medications and did not recur while rivaroxaban was reintroduced in a dose of 15 mg/d; measurement of anti-Xa activity confirmed it as a therapeutic dose. Amiodarone, that had been used for a short time and well tolerated a few years before, was definitely withdrawn. CONCLUSIONS: The authors suggest, that the concomitant use of rivaroxaban and amiodarone should be very careful in patients with a history of pulmonary disease.

Use of medication for cardiovascular disease during pregnancy.

One-third of women with heart disease use medication for the treatment of cardiovascular disease (CVD) during pregnancy. Increased plasma volume, renal clearance, and liver enzyme activity in pregnant women change the pharmacokinetics of these drugs, often resulting in the need for an increased dose. Fetal well-being is a major concern among pregnant women. Fortunately, many drugs used to treat CVD can be used safely during pregnancy, with the exception of high-dose warfarin in the first trimester, angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, amiodarone, and spironolactone. A timely and thorough discussion between the cardiologist and the pregnant patient about the potential benefits and adverse effects of medication for CVD is important. Noncompliance with necessary treatment for cardiovascular disorders endangers not only the mother, but also the fetus. This Review is an overview of the pharmacokinetic changes in medications for CVD during pregnancy and the safety of these drugs for the fetus. The implications for maternal treatment are discussed. The Review also includes a short section on the cardiovascular effects of medication used for obstetric indications.

Reduced Food-Effect on Intestinal Absorption of Dronedarone by Self-microemulsifying Drug Delivery System (SMEDDS).

The oral absorption of dronedarone (DRN), a benzofuran derivative with anti-arrhythmic activity, is significantly affected by food intake. The absolute bioavailability of the marketed product (Multaq, Sanofi, U.S.) was about 4% without food, but increased to 15% when administered with a high fat meal. Therefore, to reduce the food-effect on the intestinal absorption of DRN, a novel self-microemulsifying drug delivery system (SMEDDS) was formulated and the comparative in vivo absorption studies with the marketed product were carried out using male beagle dogs either in the fasted or fed state. The SMEDDS consisted of the drug, Labrafil M 1944CS, and Kolliphor EL in a weight ratio of 1 : 1 : 2, rapidly formed a fine oil-in-water emulsion with a droplet size less than 50 nm. An in vivo absorption study revealed that the area-under-curve (AUC0-24 h) and maximal plasma concentration (Cmax) were 10.4-fold (p<0.05) and 8.6-fold (p<0.05) higher, respectively, after the marketed product was orally administered to beagles in the fed state when compared to those in the fasted state. This food-effect were remarkably alleviated by SMEDDS formulation, with AUC0-24 h and Cmax 2.9-fold (p<0.05) and 2.6-fold (p<0.05) higher in the fed state when compared to the fasted state, by facilitating intestinal absorption of DRN in the fasted state. The results of this study suggest that SMEDDS may decrease the differences in oral absorption of DRN between the prandial states, improving therapeutic efficacy as well as patient compliance.

Herb-drug pharmacokinetic interaction between carica papaya extract and amiodarone in rats.

PURPOSE: Carica papaya has been traditionally used worldwide in folk medicine to treat a wide range of ailments in humans, including the management of obesity and digestive disorders. However, scientific information about its potential to interact with conventional drugs is lacking. Thus, this work aimed to investigate the interference of a standardized C. papaya extract (GMP certificate) on the systemic exposure to amiodarone (a narrow therapeutic index drug) in rats. METHODS: In the first pharmacokinetic study, rats were simultaneously co-administered with a single-dose of C. papaya (1230 mg/kg, p.o.) and amiodarone (50 mg/kg, p.o.); in the second study, rats were pre-treated for 14 days with C. papaya (1230 mg/kg/day, p.o.) and received amiodarone (50 mg/kg, p.o.) on the 15th day. Rats of the control groups received the herbal extract vehicle. Blood samples were collected before dosing and at 0.25, 0.5, 1, 2, 4, 6, 8 and 12 h following amiodarone administration; in addition, at 24 h post-dose, blood and tissues (heart, liver, kidneys and lungs) were also harvested. Thereafter, the concentrations of amiodarone and its major metabolite (mono-N-desethylamiodarone) were determined in plasma and tissue samples employing a high-performance liquid chromatography-diode array detection method previously developed and validated. RESULTS: In both studies was observed a delay in attaining the maximum plasma concentrations of amiodarone (tmax) in the rats treated with the extract. Nevertheless, it must be highlighted the marked increase (60-70%) of the extent of amiodarone systemic exposure (as assessed by AUC0-t and AUC0-∞) in the rats pre-treated with C. papaya comparatively with the control (vehicle) group. CONCLUSIONS: The results herein found suggest an herb-drug interaction between C. papaya extract and amiodarone, which clearly increase the drug bioavailability. To reliably assess the clinical impact of these findings appropriate human studies should be conducted.

Herb-drug interaction of Fucus vesiculosus extract and amiodarone in rats: a potential risk for reduced bioavailability of amiodarone in clinical practice.

Fucus vesiculosus is a seaweed claimed to be useful for obesity management. Therefore, considering the relationship between obesity and cardiovascular diseases, this work aimed to assess the potential for an herb-drug interaction among a standardized F. vesiculosus extract (GMP certificate) and amiodarone (a narrow therapeutic index drug) in rats. In a first pharmacokinetic study, rats were simultaneously co-administered with a single-dose of F. vesiculosus (575 mg/kg, p.o.) and amiodarone (50 mg/kg, p.o.); in a second study, rats were pre-treated during 14 days with F. vesiculosus (575 mg/kg/day, p.o.) and received amiodarone (50 mg/kg, p.o.) on the 15th day. Rats of the control groups received the corresponding volume of vehicle. After analysis of the pharmacokinetic data it deserves to be highlighted the significant decrease in the peak plasma concentration of amiodarone (55.4%) as well as the reduction of systemic exposure to the parent drug (~30%) following the simultaneous co-administration of F. vesiculosus extract and amiodarone. This paper reports, for the first time, the herb-drug interaction between F. vesiculosus and amiodarone, which determined a considerable decrease on amiodarone bioavailability in rats. Therefore, the therapeutic efficacy of amiodarone may be compromised by the concurrent administration of herbal slimming medicines/dietary supplements containing F. vesiculosus.

Iodine-induced thyroid dysfunction.

PURPOSE OF REVIEW: To summarize the mechanisms of iodine-induced hypothyroidism and hyperthyroidism, identify the risk factors for thyroid dysfunction following an iodine load, and summarize the major sources of excess iodine exposure. RECENT FINDINGS: Excess iodine is generally well tolerated, but individuals with underlying thyroid disease or other risk factors may be susceptible to iodine-induced thyroid dysfunction following acute or chronic exposure. Sources of increased iodine exposure include the global public health efforts of iodine supplementation, the escalating use of iodinated contrast radiologic studies, amiodarone administration in vulnerable patients, excess seaweed consumption, and various miscellaneous sources. SUMMARY: Iodine-induced thyroid dysfunction may be subclinical or overt. Recognition of the association between iodine excess and iodine-induced hypothyroidism or hyperthyroidism is important in the differential diagnosis of patients who present without a known cause of thyroid dysfunction.

Electrophysiologic profile of dronedarone on the ventricular level: beneficial effect on postrepolarization refractoriness in the presence of rapid phase 3 repolarization.

BACKGROUND: Dronedarone (D) is developed to maintain sinus rhythm in patients suffering from atrial fibrillation. The aim of the present study was to investigate, whether dronedarone also has an antiarrhythmic potential in the ventricle and to elucidate the mechanisms for its low proarrhythmic potential in an experimental whole heart model. METHODS AND RESULTS: Thirty-five rabbits underwent chronic treatment with D (n = 15; 50 mg · kg(-1) · d(-1)) and amiodarone (A; n = 20; 50 mg · kg(-1) · d(-1)). Hearts were perfused on a Langendorff apparatus. Results were compared with hearts acutely treated with sotalol (S; 50-100 µM; n = 14). A 12-lead electrocardiogram and up to 8 ventricular epi- and endocardial monophasic action potentials showed a significant prolongation of QT interval (D: +24 milliseconds, A: +28 milliseconds, S: +35 milliseconds (50 µM), +56 milliseconds (100 µM); P < 0.02) compared with baseline. In contrast to D and A, S led to a significant increase in dispersion of repolarization and exhibited reverse use dependence. D, A, and S increased refractory period, resulting in a significant increase in postrepolarization refractoriness (effective refractory period minus action potential duration; D = +12 milliseconds; A = +14 milliseconds; S = +25 milliseconds; P < 0.05). S led to a triangular action potential configuration, whereas D and A caused a fast phase 3 prolongation. After lowering of potassium concentration, 50% of S-treated hearts showed torsade de pointes, in contrast to an absence of torsade de pointes in D and A. CONCLUSIONS: Prolongation of myocardial repolarization and postrepolarization refractoriness by D may act antiarrhythmic. A fast phase 3 repolarization in the absence of both increased dispersion of repolarization and reverse use dependence prevents proarrhythmia.

Randomised controlled trial of lipiodol transarterial chemoembolisation with or without amiodarone for unresectable hepatocellular carcinoma.

BACKGROUND: There is no consensus about the most effective method for transarterial chemoembolisation of hepatocellular carcinoma. AIM: The aim of this phase II trial was to compare the efficacy and toxicity of lipiodol transarterial chemoembolisation with amiodarone in association with pirarubicin or doxorubicin versus lipiodol transarterial chemoembolisation with anthracycline alone in a control group. METHODS: Patients with unresectable hepatocellular carcinoma and Child-Pugh A/B7 were considered eligible for the trial. transarterial chemoembolisation was repeated every 6 weeks for a maximum of 4 sessions. RESULTS: Thirteen patients were randomised in the amiodarone group, and 14 were randomised in the control group. The two groups were comparable with respect to their baseline characteristics. The objective response rate according to the EASL criteria was 62% (95% CI 35-88) in the amiodarone group and 50% (95% CI 24-76) in the control group. At 1 and 2 years, survival rates were 77% (95% CI 44-92) and 52% (95% CI 22-75) in the amiodarone group, and 57% (95% CI 28-78) and 40% (95% CI 15-65) in the control group, respectively. There was no difference between the two groups in terms of toxicity. CONCLUSIONS: The results of this study suggest that lipiodol transarterial chemoembolisation with anthracycline and amiodarone was safe but did not increase survival compared with lipiodol transarterial chemoembolisation with anthracycline alone in patients with hepatocellular carcinoma.

N-3 polyunsaturated fatty acids administration does not reduce the recurrence rates of atrial fibrillation and inflammation after electrical cardioversion: a prospective randomized study.

OBJECTIVE: The purpose of the present prospective randomized study was to evaluate the effects of n-3 polyunsaturated fatty acids on recurrence rates of atrial fibrillation (AF) and inflammation after electrical cardioversion. METHODS: Calculation of the number of patients needed was based on the assumption of 20% and 65% chance of maintaining sinus rhythm with amiodarone and with polyunsaturated fatty acids, respectively. To observe a significant difference with an alpha level of 0.05 and a power of 0.80 it was necessary to include 22 patients in each group. A total of 47 patients were randomized to amiodarone (n=24) and amiodarone plus n-3 polyunsaturated fatty acids (n=23) groups before scheduled electrical cardioversion. The end-point was the recurrence of AF during 12-month follow-up. Effect of n-3 polyunsaturated fatty acids on inflammation was evaluated with high sensitivity C-reactive protein level measurements. Statistical analysis was performed using unpaired Student' t, Mann Whitney U and Chi-square tests. We analyzed the recurrence of AF using the Cox proportional hazards regression model to control for potentially confounding factors. RESULTS: Nine patients in the amiodarone group (37.5%), and 9 patients in the amiodarone plus n-3 polyunsaturated fatty acids group (39.1%) had recurrence of AF during follow-up (p=1). With the Cox proportional model, risk factors for the recurrence of AF were previous electrical cardioversion (HR 10.33, 95% CI 1.74 to 61.10, p=0.01) and high sensitivity C-reactive protein levels (HR 1.07, 95% CI 1.02 to 1.38, p=0.007). High sensitivity C-reactive protein levels at baseline, at day 15 and during AF recurrence were similar between two groups (p > 0.05 for all). CONCLUSION: N-3 polyunsaturated fatty acids administration does not reduce the recurrence rates of atrial fibrillation and inflammation.

Topical application of a biodegradable disc with amiodarone for atrial fibrillation.

BACKGROUND: Amiodarone is a potent anti-atrial fibrillation (AF) agent; however, its systemic administration induces serious side effects such as interstitial pneumonia. To avoid such effects, we developed a local sustained-release system for amiodarone. METHODS: A biodegradable, cross-linkable dextran disc was developed as a sustained-release carrier for amiodarone. Under general anesthesia, Japanese white rabbits underwent median sternotomy and the biodegradable disc with or without amiodarone (30 mg) was implanted onto the surface of the right atrium. Three days after implantation, we measured tissue amiodarone concentrations (n = 5), the AF threshold, and the atrial effective refractory period of the left atrium by using the Langendorff apparatus. The incidences of induced AF evoked by rapid pacing were measured and compared. RESULTS: The right atrial concentration of amiodarone was far higher than that in the lungs, ventricles, or other organs (p < 0.01). The blood concentration of amiodarone was below detectable levels. The amiodarone biodegradable disc significantly increased the AF threshold (amiodarone group, 6.9 ± 4.6 mA versus control group, 0.5 ± 0.6 mA; p < 0.01) and the effective refractory period (amiodarone group, 53.9 ± 8.9 milliseconds versus control group, 43.9 ± 9.5 milliseconds; p = 0.035) of the left atrium, indicating the electrophysiologic effect of the amiodarone biodegradable disc on the left atrium. Further, the amiodarone group was significantly less likely to experience AF, as compared with the control group (p < 0.01). CONCLUSIONS: This approach may be a less invasive and effective therapeutic option for preventing postoperative AF.

Clinical observation on the treatment of atrial fibrillation with amiodarone combined with Shenmai Injection (参麦注射液).

OBJECTIVE: To observe the therapeutic efficacy and safety of amiodarone combined with Shenmai Injection (参麦注射液) on atrial fibrillation. METHODS: A total of 351 patients with atrial fibrillation caused by cardiovascular diseases and idiopathic atrial fibrillation were assigned to amiodarone group (control group, 128 cases) and amiodarone combined with Shenmai Injection group (treatment group, 223 cases). The patients in the control group received intravenous injection of 150 mg amiodarone in 10 min, followed by intravenous drip infusion at 1 mg /min and 6 h later at 0.5 mg /min until 48 h or cardioversion. The patients in the treatment group received the same treatment of amiodarone, while in addition, they received an injection of Shenmai Injection of 100 mL simultaneously. Blood pressure, ventricular rate, and cardioversion were observed. RESULTS: The total efficiency rate was 98% (control group) and 99% (treatment group) (P>0.05). The mean ventricular rate decreased 23% and 31% in the control group and the treatment group, respectively (P<0.05). The mean cardioversion time of the two groups was 570±211 min and 351±123 min, respectively (P<0.05). Only mild side effects were observed in both groups. CONCLUSION: Compared with amiodarone, amiodarone combined with Shenmai Injection takes effect more quickly with low side effects on the treatment of atrial fibrillation.

Amiodarone and thyroid dysfunction.

Amiodarone is a potent antiarrhythmic drug associated with thyroid dysfunction. Its high iodine content causes inhibition of 5'-deiodinase activity. Most patients remain euthyroid. Amiodarone-induced thyrotoxicosis (AIT) or amiodarone-induced hypothyroidism (AIH) may occur depending on the iodine status of individuals and prior thyroid disease. AIT is caused by excess iodine-induced thyroid hormone synthesis (type I AIT) or by destructive thyroiditis (type II AIT). If the medical condition allows it, discontinuation of the drug is recommended in type I AIT. Otherwise, large doses of thioamides are required. Type II AIT is treated with corticosteroids. Mixed cases require a combination of both drugs. Potassium perchlorate has been used to treat resistant cases of type I AIT but use is limited by toxicity. Thyroidectomy, plasmapheresis, lithium, and radioiodine are used in select cases of AIT. AIH is successfully treated with levothyroxine. Screening for thyroid disease before starting amiodarone and periodic monitoring of thyroid function tests are advocated.