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At least 19 recordsLinked to original sources

PubMed1986

Comparison of the parasympatholytic activity of ACC-9358 and disopyramide.

ACC-9358 (N-[(3,5-di(pyrrolidinylmethyl)-4-hydroxy)benzoyl]aniline) is a newly developed analogue of changrolin, an antiarrhythmic agent used in the Peoples Republic of China. Since changrolin and other antiarrhythmic agents exert parasympatholytic activity which may limit their clinical usefulness, it was of interest to examine the parasympatholytic effects of ACC-9358. For comparative purposes we also studied the parasympatholytic activity of disopyramide. In guinea-pig isolated ileal strips, disopyramide, 3-30 microM, and ACC-9358, 100-300 microM, competitively antagonized carbachol-induced contractions with pA2 values of 5.78 and 4.17, respectively. In guinea-pig isolated right atria, disopyramide 3-30 microM, competitively antagonized methacholine-induced slowing of spontaneous beating with a pA2 value of 5.99 whereas ACC-9358, 3-300 microM, produced no significant muscarinic blockade in this preparation. Disopyramide (1.9-15 mg kg-1, i.v.), but not ACC-9358 (7.5-1.5 mg kg-1, i.v.), significantly increased rat pupil diameter in vivo. Disopyramide and ACC-9358 blocked vagal-induced reductions in heart rate in dogs anaesthetized with pentobarbitone. ED50 values were approximately 0.65 and 11.25 mg kg-1, respectively. We conclude that ACC-9358 possesses significantly less parasympatholytic activity than disopyramide.

Animals↗

PubMed1984

Synthesis and antiarrhythmic and parasympatholytic properties of substituted phenols. 2. Amides.

Thirty amides patterned after the antiarrhythmic drug changrolin were synthesized and their antiarrhythmic and parasympatholytic activities were assessed. There was no correlation between antiarrhythmic and parasympatholytic activities. Several of the amides were found to be potent antiarrhythmic agents that possessed low parasympatholytic activity. All of the compounds appear to act by a class I mechanism.

Amides↗

PubMed1999

Spectral analysis of heart rate variability as a quantitative measure of parasympatholytic effect--integrated pharmacokinetics and pharmacodynamics of three anticholinergic drugs.

The time course and concentration-effect relationship of parasympatholytic effects of three anticholinergic drugs were investigated using spectral analysis of heart rate (HR) variability. Single intravenous (i.v.) doses of atropine (10 microg/kg), glycopyrrolate (5 microg/kg), scopolamine (5 microg/kg), and placebo were given to eight healthy volunteers in a double-blind, randomized cross-over study. Electrocardiogram (ECG) was recorded at baseline and 2.5, 5, 10, 20, and 30 minutes, and 1, 1.5, 2, 3, 4, 5, and 6 hours after drug administration, while the subjects breathed at a fixed 0.25 Hz frequency. The powers of two frequency bands (low frequency [LF] = 0.07-0.15 Hz and high frequency [HF] = 0.15-0.40 Hz) were calculated using stationary time series of R-R intervals (RRI) free from ectopic beats. To perform pharmacokinetic-pharmacodynamic (PK-PD) modeling, venous plasma drug concentrations were measured. Atropine and glycopyrrolate, and, to a lesser extent, scopolamine induced decreases in HF power and increases in LF/HF ratio of HR variability, indicating parasympatholytic activity and corresponding changes in sympathovagal balance. Maximal average decreases in HF power were 99%, 94%, and 82%, respectively, but in two scopolamine subjects, a parasympathomimetic effect was dominant. Interindividual variability was least for the Hayano index of HF power (square root (RRI HF-power)/RRI*100), and profound and consistent decreases were seen after atropine and glycopyrrolate. Pharmacokinetics were best fitted to a two-compartment open model, and effect compartment link modeling using the Hayano index was performed with the atropine and glycopyrrolate data. The best description of the PK-PD relationship for both drugs was achieved using the sigmoidal Emax model. Mean (+/-SD) EC50, sigmoidicity factor (gamma), and equilibration rate constant (k(e0)) estimates were 1.35 (+/-0.27) ng/mL, 6.07 (+/-1.98) and 11.0 (+/-5.28) l/h for atropine and 1.35 (+/-0.49) ng/mL, 4.34 (+/-1.55) and 2.26 (+/-0.81) l/h for glycopyrrolate. Spectral analysis of HR variability appears to be a powerful tool in monitoring parasympatholytic drug activity. A sigmoidal Emax model with an extremely steep concentration-response relationship was revealed for atropine and glycopyrrolate. The effects of scopolamine were more incongruous.

Adult↗

PubMedDate not supplied

Use of parasympatholytics.

The role of the vagus in bronchial asthma implicates to suggest that parasympatholytics are potent drugs in asthma therapy. The most important parasympatholytics today are ipratropium and oxitropium bromide. They are effective by blocking the cholinergic or muscarinic receptors of the bronchial smooth muscle and thereby inhibit cholinergic bronchomotor tone. Although they are generally somewhat less effective broncholdilators compared to beta 2-adrenergics, they are potent antiasthmatic drugs especially in infants and small children, in whom beta 2-adrenergics seem to be not so much effective. As with inhaled beta 2-adrenergics a correct inhalation technique is required for an optimal effect with parasympatholytics as well, but it could be shown that both groups of substances do have a good antiobstructive effect even when just sprayed into the mouth. Apart from the theoretical implications discussed the clinical importance of these findings for the antiobstructive treatment of those patients unable to inhale properly including infants and small children is emphasized.

Administration, Buccal↗

PubMed1997

[The effect of parasympatholytics on the therapeutic effectiveness of the oxime HI-6 against organophosphorus compounds (Soman, substance VX, Fosdrin) in mice].

BACKGROUND: Causal antidotal therapy of acute intoxications with organophosphorus compounds involving administration of the parasympatholytic and cholineesterase reactivator (oxime) has not been resolved so far satisfactorily despite knowledge of the basic mechanism of action of these noxious substances. METHODS AND RESULTS: In experiments on mice the therapeutic effect of parasympatholytics atropine, benactyzine and biperidene (Akineton) combined with oxime HI-6 on the toxicity of highly toxic organophosphates soman and substance VX and the organophosphorus insecticide phosdrine was compared as regards their influence on the LD50 of these noxious substances during 24-hour survival of experimental animals. Two levels of antidotes were tested. These findings confirm that the LD50 value of untreated intoxication with all three organophosphorus compounds is most increased by oxime HI-6 combined with benactyzine regardless of the antidote dosage. CONCLUSIONS: Oxime HI-6 is the most effective against highly toxic organophosphates and organophosphorus insecticides when combined with the centrally acting parasympatholytic benactyzine.

Animals↗

PubMed1997

The influence of parasympatholytics on the resolution of acute attacks of asthma.

PURPOSE: To evaluate the role of parasympatholytics in the resolution of acute attacks of asthma. METHODS: This study employed a prospective sequential design in which the influence of 0.5 and 1.0 mg of ipratropium bromide on peak expiratory flow rates (PEFR), hospital admissions, and length of stay (LOS) in the emergency department (ED) was evaluated. The parasympatholytic was added to a well-investigated standard therapeutic regimen that was anchored by the use of repetitive doses of albuterol, and employed pretested decision algorithms. RESULTS: One hundred and thirty-one patients received ipratropium (l) and 123 who did not (NI) served as controls. There were no significant pretreatment between group differences in gender, racial composition clinical signs and symptoms, or PEFR. The presence of ipratropium in the regimen did not influence discharge/admission patterns, LOS, the rate of improvement of the patients, or the level of PEFR achieved. CONCLUSION: Anticholinergic agents such as ipratropium are not first-line treatments for acute asthma. They do not add any therapeutic benefit to the effects of albuterol given in divided doses over 1 hour, nor do they facilitate recovery in patients whose immediate response to sympathomimetics is impaired.

Acute Disease↗

PubMed1983

Synthesis and antiarrhythmic and parasympatholytic properties of substituted phenols. 1. Heteroarylamine derivatives.

Twenty-four structural derivatives of the antiarrhythmic drug changrolin were synthesized and tested for antiarrhythmic and parasympatholytic activities. It was found that while the bis(pyrrolidinylmethyl)phenol pattern of changrolin appeared to be optimal in this series, a wide latitude existed for the heteroaryl substituent for maintaining good antiarrhythmic activity. Further, the antiarrhythmic and parasympatholytic activities tended to exhibit parallel changes.

Animals↗

PubMedDate not supplied

Relative potency of the atropine-like effects of a new parasympatholytic drug, scopolamine-N-(cyclopropyl methyl) bromide and those of hyoscine-N-butyl bromide.

A double-blind crossover trial with a 4-point bioassay was carried out in 8 convalescent in-patients to study the relative potency of scopolamine-N-(cyclopropyl methyl) bromide (DA 3177), a new parasympatholytic drug, administered at doses of 2.5 mg and 5 mg i.v., and hyoscine-N-butyl bromide, administered at doses of 10 mg and 20 mg i.v., in producing atropine-like effects. The results showed that the effects on heart rate and near point of accommodation were slightly less with DA 3177, while its effects on salivary secretion were a little greater than those of hyoscine-N-butyl bromide. It is suggested that study of the pharmacodynamic effects of parasympatholytic drugs is a relatively simple way of predicting which doses should be effective spasmolytically.

Accommodation, Ocular↗

PubMed1999

Cyclic guanosylmonophosphate urinary excretion in parasympathicomimetic or parasympatholytic syndromes induced by reserpine or diphemanil-methylsulfate.

Parasympathetic hyperactivity is found in some infants presenting faint episodes and could be responsible of certain Sudden Infant Death Syndrome cases. Therefore it was interesting to look for a noninvasive biochemical indicator of parasympathetic activity. A parasympaticomimetic syndrome associated with muscarinic receptor stimulation, which has been followed during 48 h, was obtained in the awake rat by reserpine injection (6.25 mg/kg at T0 and T24h), and a model of prolonged parasympatholytic syndrome, by administration of diphemanil-methylsulfate (DPMS), a muscarinic receptor inhibitor, in drinking water (mean daily dosis: 150 mg/kg). Significant bradycardia and tachycardia were respectively observed. In the reserpine-treated rats we found significantly increased cyclic guanosylmonophosphate (cGMP) urinary excretion between T24h and T48h, when compared with vehicle-treated controls (+87% in one experiment, +135% in the other, when expressed in pmol/microg creatinine); norepinephrine urinary excretion between T24h and T48h was decreased (-44%); the increase in cGMP urinary excretion was not significantly modified by the NO-synthase inhibitor, L-nitroarginine-methyl-ester. In the DPMS-treated rats, we observed a significantly decreased cGMP (-20%) and increased norepinephrine urinary excretion (+61%). Thus cGMP excretion varied in opposite directions in the reserpine- and DPMS-treated rats. The link between these modifications in cGMP excretion and muscarinic receptor stimulation or blockade has still to be fully demonstrated. Urinary cGMP excretion could be tested as screening parameter in infants at risk of faint episodes associated with bradycardia.

Animals↗

PubMed1976

Drug treatment of trigeminal neuralgia with sympatho- and parasympatholytics.

Exciting factors in trigeminal neuralgia known to date are reviewed, and the involvement of the vegetative system in the development of neuralgic pain is documented by clinical observations. Studies of free fatty acids (ffs) and free glycerin (FGly) conducted to assess sympathetic and vegal involvement revealed a sympathetic component to be active in attacks along the distribution of the first and second trigeminal branches, while pain originating from the third branch appears to be mediated by vagal stimuli. Sy,patho- and parasympatholytic therapy is discussed and its effect reviewed in a large group of cases. More than 50% of cases were found to be improved.

Adult↗

PubMed1985

Synthesis and antiarrhythmic and parasympatholytic properties of substituted phenols. 3. Modifications to the linkage region (region 3).

As part of a continuing program of systematically modifying the structure of the class I antiarrhythmic drug changrolin, we synthesized 15 analogues in which the linkage between the two aromatic regions was altered. High antiarrhythmic activity and low parasympatholytic activity was found when the linkage region, designated region 3, contained a carbonyl moiety, including ketones, amides, and ureas. Secondary amides were superior to tertiary amides, while amide reversal resulted in no change in activities. One compound in this series, 7, 2,6-bis(1-pyrrolidinyl-methyl)-4-benzamidophenol (ACC-9358), is undergoing preclinical evaluations.

Animals↗

PubMed1975

Comparative studies of parasympatholytic drugs on stomach (double blind test) and analysis of relation between gastric form and tonus.

Effects of 3 kinds of parasympatholytic drugs (timepidiumbromide, hyoscine-N-butylbromide and prifinium-bromide) and placebo (physiological saline solution) on the gastrointestinal tract were evaluated roentgenographically by double blind technique in a total of 101 male human subjects. The results may briefly be summarized as follows: 1. There were significant differences on hypotonic rate being one of the indexes of the gastric tonus between timepidium-bromide and placebo. The effects of 3 experimental drugs were significantly high as compared with that of placebo on peristaltic movement of the stomach. The effect of timepidium-bromide was significantly different from that of placebo on the site of arrival of barium. 2. The comparison of degrees of the gastric tonus between main and control tests revealed that the effect of placebo obtained in the main test was significantly inferior to that of hyoscine-N-butylbromide obtained in the control test, whereas there existed no significant differences of the effects among 3 active drugs. 3. Effects of each drug on the gastric tonus which was scored by hypertonic, normotonic and hypotonic state were evaluated by stratification. The result showed that the effect of timepidium-bromide was significantly greater than that of placebo. 4. All active drugs were not significantly different in terms of 7 observed values each on the gastric form.

Adhesiveness↗

PubMed1992

Parasympatholytic effects of vecuronium are mediated by nicotinic and muscarinic receptors in hearts of anesthetized dogs.

We investigated the blocking effects of vecuronium and pancuronium on the negative chronotropic and dromotropic responses to stimulation of the parasympathetic nerves in the anesthetized, open-chest dog. We stimulated the intracardiac parasympathetic nerves to the SA nodal region (SAP stimulation) or to the atrioventricular nodal region (AVP stimulation). SAP stimulation or AVP stimulation selectively decreased heart rate or increased atrioventricular conduction time, respectively. Vecuronium and pancuronium inhibited the chronotropic response to SAP stimulation and the dromotropic response to AVP stimulation in a dose-dependent manner. The ID50 of each drug for the dromotropic response was less than that for the chronotropic response. The blocking effect of vecuronium on the negative cardiac responses to parasympathetic stimulation was about 10-fold less potent than that of pancuronium. These results suggest that the blocking effects of vecuronium and pancuronium on the negative chronotropic and dromotropic responses to parasympathetic stimulation differ from those of atropine in the heart. In the isolated right atrium perfused with blood from the support dog, vecuronium, injected into the external jugular vein of the support dog, dose-dependently inhibited the negative chronotropic and inotropic responses to carbachol or SAP stimulation and the negative followed by positive chronotropic and inotropic responses to nicotine. The ID50 values for carbachol, nicotine and SAP stimulation were not significantly different. These results suggest that parasympatholytic effects of vecuronium are mediated by not only muscarinic receptors but also neuronal nicotinic receptors in hearts of anesthetized dogs.

Anesthesia↗

PubMed1975

[Interactions of some parasympatholytics and structurally similar drugs with bovine serum albumin].

The interactions of the parasympatholytic drugs adiphenin, adiphenin H and propanthelin and the structurally related compounds, diphenhydramine, D-propoxyphene and methadone with bovine serum albumin (BSA) are studied by equilibrium dialysis and ultracentrifugation. The results show that BSA has a few binding sites (n less than 10) for the mentioned drugs. The association between the compounds under study and BSA are relatively weak. The binding constants are in the range of 10(3) l/Mol.

Binding Sites↗

PubMed1975

[Studies on the binding of some parasympatholytics to bovine serum albumin/measurement of relaxation times (author's transl)].

The interactions of the parasympatholytic drugs adiphenin, adiphenin H and propantheline and the structurally related compounds diphenhydramine, D-propoxyphene and methadone with bovine serum albumin (BSA) are studied by means of 1H-NMR-spectroscopy. The relaxation rates of essential protons or proton groups of the bound ligands are obtained by a plot of the observed relaxation rates, which are determined from the alterations of the line widths in the presence of BSA, versus the biopolymer concentration. From the stabilization factors R thus obtained it can be concluded that there exist defined but relatively weak associations between these drugs and BSA; both the hydrophobic aryl moieties and the ionized amino groups are involved in these interactions.

Dextropropoxyphene↗

PubMed1986

[The problem of the impairment of the action of parasympatholytic substances. Ophthalmologic criteria and methods].

UNLABELLED: The parasympatholytic effects on the eye were investigated in 12 healthy volunteers. In a randomized cross-over double-blind trial 20 or 40 mg N-butylscopolaminium bromide (Buscopan) or placebo was given by i.v. injection. Pupillary light reaction, range of accommodation, visual acuity, and nyctometer values were measured up to 45 min after injection. RESULTS: 1. The mydriatic effect of both dosages of the drug is moderate. Pupil diameters at the end of the light reaction are only slightly greater under the influence of the drug than in control experiments. The dynamics of the reaction remains unaltered. 2. The range of accommodation diminishes in a dose-dependent manner. 9-15 min after the injection the inhibition is maximum. 45 min after injection, even of the 40 mg dosage, only a small effect remains. 3. Visual acuity and nyctometer values are not affected by N-butylscopolaminium bromide. The findings were discussed with respect to the ability to meet the requirements of road traffic.

Adult↗

PubMed1981

A comparative study of two parasympatholytic bronchodilator agents: ipratropium bromide and diphemanil methylsulfate.

Ipratropium and diphemanil are synthetic quaternary ammonium compounds with antimuscarinic properties. By using in vitro measurements of tension changes in isolated guinea-pig trachealis muscle strips and in vivo measurements of lung mechanics changes in anesthetized, vagotomized cats, the two drugs were compared in terms of their relative bronchodilator potency, mode of action and apparent site of activity in the bronchial tree. Ipratropium and diphemanil were about equipotent in antagonizing airway smooth muscle contraction induced by the cholinergic agonists, methacholine (in vitro) and carbachol (in vivo). When noncholinergic stimulation was used to augment smooth muscle tone, i.e., hypertonic potassium in the isolated preparations and serotonin in the vagotomized animals, only diphemanil exhibited significant bronchodilator activity. Simultaneous measurements of pulmonary resistance and dynamic compliance were used to partition in vivo bronchodilator effects between large and small airways. The parasympatholytic bronchodilator effects of both drugs were distributed uniformly along the bronchial tree, whereas the direct spasmolytic action of diphemanil appeared to manifest itself preferentially on large airways.

Animals↗

PubMed1984

Effect of inhaled diphemanil methylsulfate, a parasympatholytic agent, on histamine induced bronchoconstriction in asymptomatic asthmatics.

Parenterally administered diphemanil methylsulfate, a quarternary ammonium compound with both parasympatholytic and direct bronchial smooth muscle relaxing properties, has been found effective in the treatment of bronchial asthma. The present study was undertaken to test the effectiveness of inhaled diphemanil in preventing histamine induced bronchoconstriction in asymptomatic adult asthmatics. Twenty subjects, aged 19-40 years (average 25) were studied, each on three different days, observing an interval of at least 70 hours between testing. On day one, airway sensitivity to inhaled histamine was determined. On days two and three, histamine challenge was repeated 20 minutes after inhalation of either diphemanil (2 mg) or its vehicle in a double-blind crossover design. Airway sensitivity was assessed by determining cumulative log dose units of inhaled histamine required to provoke a 20% decline in FEV1 (log PD20 - FEV1). Diphemanil did not prevent histamine induced bronchoconstriction nor did it significantly affect log PD20 - FEV1 (p = 0.59). We conclude that a 2 mg dose of diphemanil, administered by oral inhalation 20 minutes before histamine challenge, is ineffective in protecting against induced bronchospasm in asymptomatic adult asthmatics.

Administration, Intranasal↗