Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twelve patients with severe ventricular dysrhythmias were treated by one single dose of 250 mg of mexiletine injected intravenously over a 15 min. period. All patients showed some antiarrhythmic response. In 9 cases, the ventricular premature beats were totally or almost totally abolished up to 20 to 100 min. after the end of the infection. In most patients (5/7), there existed a correlation between the plasma concentration of the drug and the antiarrhymic action. However, the drug levels were not different in the good responders as compared to the poor responders or in those who manifested a prolonged antiarrhythmic activity as compared to the others. Side-effect appeared in three cases and consisted of vomiting, tremor, and episodes of sinus arrest.
Acta Cardiol 1977
PMID:The efficacy of intravenous mexiletine on ventricular ectopic activity. 7 54

Pigs in which venous catheters were positioned for long-term use were injected i.v. with high doses of nicotine in physiol. saline. The LD50 was 2.656 mg/kg body weight. Clinical symptoms were mainly: forced respiration, muscular tremor to tetanoid spasms, cyanosis of the skin, salivation and sometimes vomiting. The degree and duration of symptoms were dose-dependent. Ecg changes in anaesthesized pigs following intravenous nicotine injections of 0.126 mg/kg and 0.378 mg/kg at 15 minutes' interval were immediately commencing disturbances of the heart rate in form of bradycardia and asystolia. After 5 sec we observed extrasystoles, tachycardia, sino-auricular block and AV-block of first and second degree as well as a number of T- and P-changes. Changes of the ecg were observed generally for 10 to 15 min, however, the T-wave remained sometimes negative or biphasic-preterminal negative for some hours.
Basic Res Cardiol
PMID:Effect of high doses of nicotine in pigs. I. Changes of the electrocardiogram. 125 87

The antianginal efficacy of bepridil, a calcium antagonist with an extended plasma elimination half-life, has been compared with placebo and the calcium antagonists nifedipine and diltiazem in patients refractory to diltiazem. The earliest observations in the United States of antianginal effects of bepridil were revealed in a single-blind, multicenter, placebo-controlled trial of 77 patients with chronic stable angina pectoris that demonstrated that bepridil (300 mg/day) improved exercise duration by 26%, from 6.9 +/- 0.4 (standard error of the mean) to 8.7 +/- 0.5 minutes (p less than 0.001), and exercise work by 52%, from 2.7 +/- 0.3 to 4.1 +/- 0.4 x 10(-3) KPM (p less than 0.001), on a standardized treadmill protocol, and it reduced angina frequency by 68%, from 8.5 +/- 1.1 to 2.7 +/- 0.7 attacks per week, and nitroglycerin use by 76% (p less than 0.001). Minor side effects such as nausea, epigastric discomfort, and tremor were infrequent and no major side effects occurred. Double-blind, parallel-design treatment evaluations confirmed beneficial effects of bepridil alone and in combination with beta blockade. Chronic efficacy was confirmed by evaluations up to 24 months in a controlled withdrawal study. Antianginal effects of nifedipine were compared with those of bepridil in a double-blind, parallel group study of 101 patients with chronic stable angina treated for 3 months. Bepridil (mean final dose 284 mg/day; range 200-400 mg/day) produced modest but statistically significantly (p less than 0.05) greater improvements in exercise work, time to angina, or 1 mm ST-segment change than nifedipine (mean final dose 59 mg/day; range 30-120 mg/day).(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Cardiol 1992 Apr 09
PMID:Bepridil treatment of chronic stable angina: a review of comparative studies versus placebo, nifedipine, and diltiazem. 153 68

Mexiletine is a Class IB antiarrhythmic which has basic and clinical electrophysiologic properties similar to lidocaine. Like other Class I antiarrhythmic agents, mexiletine blocks the rapid inward sodium current responsible for phase 0 of the action potential. It has been noted in the clinical electrophysiology laboratory to have minimal effect on sinus node function and AV nodal and His-Purkinje system conduction. Pharmacokinetic studies have shown that oral absorption is rapid with bioavailability of 80-90%. Mexiletine is predominantly metabolized by the liver with elimination half-life of 9 to 12 hours. The antiarrhythmic effects of the primary drug's metabolites remain to be defined. Hemodynamic studies have shown mexiletine to have a lesser negative inotropic effect than procainamide or disopyramide. Although mexiletine as a single agent successfully suppresses 60 to 80% of spontaneous ventricular arrhythmias, it has lower efficacy in suppression of induced ventricular arrhythmias. Multiple studies have shown that as monotherapy mexiletine is effective in preventing the induction of ventricular tachycardia in approximately 20% of patients. When used in combination with a Class IA antiarrhythmic drug for suppression of induced ventricular arrhythmias, multiple investigators have reported greater efficacy. Neurological side effects (tremor, dizziness, memory loss) occur in approximately 10% of patients while gastrointestinal side effects (nausea, anorexia, gastric irritation) occur in up to 40% of patients. Proarrhythmia or other serious toxicity from the drug is uncommon.
Clin Cardiol 1990 May
PMID:Mexiletine: pharmacology and therapeutic use. 218 14

Pentylenetetrazole (75 mg/kg) induced a characteristic coarse body tremor (accompanied by limb extension) and hyperactivity in 4-day-old rat pups. These effects were reversed by diazepam (0.5 and 2 mg/kg) but not by CL 218,872 (10 and 20 mg/kg) which is selective for type 1 benzodiazepine receptors. Diazepam did not affect the brain concentrations of pentylenetrazole, indicating that the reversal was not based on a pharmacokinetic interaction. Neither diazepam nor CL 218,872 had significant effects on the behavior of the rat pups, although diazepam (2 mg/kg) tended to increase locomotor activity. The results suggest that diazepam displays an anticonvulsant effect in the neonatal rat which is mediated by type 2 receptors.
 ...
PMID:Diazepam reverses the effects of pentylenetetrazole in rat pups by acting at type 2 benzodiazepine receptors. 254 9

Tremors of the isoelectric line in routine electrocardiograms have been described in patients with spinal muscular atrophy and have been interpreted as fasciculations of denervated muscles. In order to evaluate this phenomenon, 13 patients with spinal muscular atrophy have been studied (average age: 37.3 months). A first electrocardiogram was recorded routinely; a second tracing was then recorded with double sensitivity and double speed. In addition, all patients were evaluated clinically and had M-mode and cross-sectional echocardiography. Regular and constant spikes on the isoelectric electrocardiographic line were recorded in 12 patients (93.4%); their frequency ranged from 39 to 48 cycles/sec (average: 42.08 +/- 2.64). Contrary to previous reports, we found an "abnormal" electrocardiogram in all our patients with severe spinal muscular atrophy. The only patient with a normal electrocardiogram had a mild and clinically stable form of spinal muscular atrophy. We did not find any significant structural cardiac abnormality by clinical and echocardiographic evaluation. We conclude that continuous tremor on the isoelectric line of electrocardiogram represents a characteristic of spinal muscular atrophy in these patients. It is a result of muscle fasciculations and does not imply any abnormality of the heart.
Int J Cardiol 1989 Sep
PMID:Electrocardiographic abnormalities in childhood spinal muscular atrophy. 276 7

A data base of 1,245 patients treated for ventricular arrhythmias, most of whom had serious cardiac disease, was reviewed. Only 2.9% of these patients had benign ventricular arrhythmias without structural heart disease. The overall incidence of proarrhythmia in this population was 9.2% (115/1,245), but was as frequent as 16% in patients with a history of cardiomyopathy. The proarrhythmic form was new sustained ventricular tachycardia in 22 patients (1.8%). Only 2 of 71 patients (2.8%) with primary arrhythmia had a proarrhythmic event. The incidence has decreased markedly over the past years as reduced doses and gradual titration have been used. There were 137 deaths in the data base of which 82 were sudden, all in patients with advanced (79) or moderately severe (3) cardiac disease. High initial doses, prior myocardial infarction and congestive heart failure (CHF) were positively associated with sudden cardiac death. There were no deaths among the 71 patients with benign arrhythmias. Death rates were related to the severity of the arrhythmia being treated. Comparisons with published survival curves indicated modest improvement; in no case was survival decreased. Invasive and noninvasive measures of left ventricular function indicated no adverse hemodynamic effects. There was only 1 case of new and 3 cases of worsened CHF probably related to encainide. Only 5 patients discontinued for CHF or related signs and symptoms. The most frequent drug-related noncardiac adverse reactions were dizziness (26%), abnormal or blurred vision (19%), QRS interval prolongation (5%), taste perversion (4%) and tremor (3%). In conclusion, the use of reduced doses and gradual titration of encainide has markedly decreased the incidence of proarrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Cardiol 1986 Aug 29
PMID:Safety of encainide for the treatment of ventricular arrhythmias. 309 26

The efficacy of the new class Ic anti-arrhythmic (aa) drug, Flecainide, has been evaluated in patients (pts) affected by frequent and/or severe chronic ventricular arrhythmias (VA), as assessed by 24 hours Holter monitoring and maximal exercise stress testing. The protocol consisted in a preliminary screening with multiple aa drugs (average 6.0 per pt) using the acute oral drug testing. The most effective drug was then given for 72 hours and 24 hours Holter monitoring and exercise stress testing repeated; if the efficacy was confirmed, chronic treatment was initiated and control visits were repeated after 3, 6 and 12 months. The study population consisted of 27 pts; 22 (81%) were in Lown class 4A (18%) or 4B (63%). Eight pts (30%) had a previous (greater than 1 year) myocardial infarction, while in 14 (52%) no evidence of cardiac disease was found. During acute oral drug testing a positive response (reduction of PVC's greater than 90% and abolition of grades 4A and 4B) was obtained with Flecainide, 200 mg, in 20 pts (74%). In 6 pts (22%) no effect was observed, while a possible proarrhythmic effect was observed in 1 pt (4%). Eighteen pts entered the second phase of the study with an average dose of Flecainide of 175 mg b.i.d. In 83% of the pts there was a positive concordance between the acute oral testing and the 72 hours treatment, as in 15 out of 18 pts grades 4A and 4B were totally abolished and the mean frequency of PVC's was reduced by 99%. In 3 pts (17%) no response was observed. Flecainide increased significantly PR (37 msec), QRS (20 msec) and QTc (28 msec). The plasma levels attained with chronic therapy (846 ng/ml) were higher than those achieved with the acute oral testing (372 ng/ml). Mild side effects (dizziness, tremor and headache) were observed in 33% of the pts and were all eliminated by a 100 mg reduction in Flecainide dose. Fifteen pts entered the third phase (long term treatment): in this group there was a 93.3% correlation with phase two, as in 14 out of 15 pts there was a complete abolition of grade 4B arrhythmias, a 98.8% reduction of couplets and a reduction in the number of PVC's greater than 85%. This study shows that Flecainide is a quite powerful aa drug with modest side effects. Its efficacy against chronic VA is high, also when compared to the most effective and available aa drugs.(ABSTRACT TRUNCATED AT 400 WORDS)
G Ital Cardiol 1985 Mar
PMID:[Evaluation of flecainide in the therapy of chronic ventricular arrhythmia using the acute oral load method]. 401 65

The antiarrhythmic effects of the sustained release form of mexiletine (Mexitil-Perlongets) were evaluated in a double-blind placebo trial in 630 patients with recent documented myocardial infarction. The primary response variable was based on central reading of 24 hour ambulatory electrocardiographic recordings and was defined as the occurrence of 30 or more single premature ventricular complexes in any two consecutive 30 minute blocks or one or more runs of two or more premature ventricular complexes in the entire 24 hour electrocardiographic recording. Large differences, regarded as statistically significant, between the mexiletine and placebo groups were noted in that end point at months 1 and 4, but only trends were observed at month 12. These differences were observed even though the serum mexiletine levels obtained in this study were generally lower than those observed in studies that have used the regular form of the drug. There were more deaths in the mexiletine group (7.6%) than in the placebo group (4.8%); the difference was not statistically significant. The incidence of coronary events was similar in both groups. Previously recognized side effects, particularly tremor and gastrointestinal problems, were more frequent in the mexiletine group than in the placebo group.
J Am Coll Cardiol 1984 Dec
PMID:International mexiletine and placebo antiarrhythmic coronary trial: I. Report on arrhythmia and other findings. Impact Research Group. 620 18

A placebo-controlled, randomized, double-blind, crossover study was performed in 14 patients with chronic, resistant, ventricular arrhythmias in order to evaluate the efficacy and safety of two new antiarrhythmic agents, propafenone and aprindine. After an initial placebo phase, patients received orally either propafenone (600 mg daily) or aprindine (150 mg daily for the first two days and 50 mg every 12 hours successively) for five days. This treatment was followed by a drug-free period (placebo II); patients were then crossed over to the alternative drug. A 24-hour Holter recording was performed during the last 48 hours of the initial placebo phase and on the final day of each phase of the crossover period. Analysis of Holter recordings revealed that the mean hourly PVCs frequency, for the group, was similar during the two control periods. Significant reduction in the mean hourly frequency of PVCs from control levels was observed in 78% of the patients during propafenone therapy and in 42% during aprindine therapy. For the whole group, propafenone induced a significant reduction of the average PVCs/h frequency (p less than 0.05), whereas the aprindine was ineffective. Finally no patient experienced side effects with propafenone, whereas aprindine caused side effects in three patients (dizziness, tremor, ataxy).
G Ital Cardiol 1983
PMID:[Comparison of the anti-arrhythmic effects of propafenone and aprindine in the treatment of refractory chronic ventricular arrhythmias. A randomized double-blind crossover study controlled with placebo]. 635 29


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