#bronchodilation

[maddison555brooksild]

New Post has been published on All about Asthma

New Post has been published on http://no-asthma.com/ventolin-inhalers-drugs-for-treatment-asthma.html

Ventolin Inhalers: Drugs for Treatment Asthma

Eleven subjects enrolled in the study, seven men and four women (Table 1). All gave a clinical history of asthma for at least five years (mean 26.5 years, SD 15.2). Mean age was 32.7 years (SD 14.7), and mean baseline FEV1 was 64.4 percent of predicted (SD 10.8 percent). Three subjects reported hay fever or pollen allergy, five had drug allergies, and four reported no allergic history. The two subjects with the lowest pre-study FEV1 level did not complete all 12 hours of the protocol on all study days. One subject stopped three hours after receiving placebo and four hours after glycopyrrolate doses of600 and 1,200 μg. The second subject stopped four hours after receiving placebo and seven hours after receiving 200 μg of glycopyrrolate. These two subjects completed the entire protocol for all other glycopyrrolate doses. All available observations from these patients were included in the statistical analysis.

All doses of glycopyrrolate produced significant improvement in FEV1 and FVC from one-half hour through eight hours after treatment (p<0.05, Fig 1 and 2). At 12 hours, FEV1 and FVC values for all doses of glycopyrrolate were higher than placebo but the differences did not reach statistical significance. No differences were found between the individual doses of glycopyrrolate. Four patients reported a total of seven side effects in 44 drug treatments (Table 2). Side effects were not dose related. There were no differences between placebo and drug groups in pulse rate or blood pressure. No changes in the ECG were seen.

Discussion

In this study, inhaled glycopyrrolate improved airway obstruction in patients with nonexercise-induced asthma. Mean improvements in percent predicted FEVx and FVC were significantly better than placebo from one half hour through eight hours after drug treatment. The drug was well tolerated by patients at all doses tested; only minimal anticholinergic side effects were reported. Glycopyrrolate is similar to ipratropium bromide, another quaternary ammonium compound with anticholinergic properties. Both compounds produce bronchodilation with minimal anticholinergic side effects; however, the duration of action of glycopyrrolate appears to be longer than that shown with ipratropium. The safety of glycopyrrolate has been established by extensive clinical use orally to control gastric acidity, parenterally as an anti-sialogogue, and as an antimuscarinic during reversal of neuromuscular blockade. The main idea of asthma treatment is ventolin inhaler which is directed to the asthma attack arrest. To know more about ventolin inhalers you may on buy-asthma-inhalers-online.com.

The eight-hour duration of action of glycopyrrolate is unusual among ventolin inhaled bronchodilators. Most inhaled beta agonists have only a four to six hour duration of action. Although not statistically significant, all doses of glycopyrrolate tested led to greater improvement in FEVi and FVC than placebo through 12 hours. The lack of statistical significance at ten and 12 hours may be because the study, limited by multiple comparisons and small sample size, did not have the statistical power to detect a small but clinically significant effect. The loss of statistical significance after eight hours may reflect the loss of data from the two patients who also were unable to tolerate placebo beyond three and four hours, respectively. Of note, both subjects benefited from drug therapy; one subject completed the entire 12 hours on three drug treatment days and the other on two drug treatment days.

Patients varied in their responses to glycopyrrolate. Clinical parameters, including response to isoproterenol, did not predict which patients were likely to respond. In clinical practice, it may be useful to give patients glycopyrrolate and monitor their change in FEVi or FVC to identify patients especially likely to benefit from therapy. This study was unable to show a difference among the various doses of glycopyrrolate tested. Doses even smaller than 100 μg may be effective.

Glycopyrrolate offers promise as an effective drug to treat patients with asthma. It may be useful in asthmatic patients who require a long-acting bronchodi-lator, including patients with early morning exacerbations of asthma interfering with sleep. It may also help patients who have unacceptable adrenergic side effects from betag agonist agents or patients who do not respond adequately to betas agonist treatment. Additional studies should include trials directly comparing glycopyrrolate to betas agonists and trials of glyco-pyrrolate in conjunction with betas agonists.

Table 1—Patient Description

PatientNo. Age Sex Prestudy Medications PrestudyFEV* Theophylline Beta-Agonist Inhaled Steroid 1 18 M X X 3.31 (75) 2 20 M X 3.09 (67) 3 22 M X 3.50 (80) 4 23 F X X 2.56 (69) 5 25 M X X 3.45 (76) 6 27 F X X X 1.42 (54) 7 31 M X X 2.93 (67) 8 31 M X 2.08 (48) 9 47 M X 2.56 (66) 10 48 F X X X 1.00(45) 11 68 F X X X 1.61 (61) Means 32.7….. ……..2.50 (64.4) SD 14.7….. ……..0.82 (10.8)

Table 2—Side Effects Observed After Glycopyrrolate

Patient Side Effect Dose(ws) Duration(hr) A Headache 1200 1.5 B Dry mouth 1200 12 C Dry mouth 200 12 Dry mouth 1200 12 D Blurred vision 200 4 Lightheaded 600 6 Blurred vision 600 4

Figure 1. Mean percentage of change over time in FEVj as percent predicted in patients receiving a single inhaled dose of placebo or glycopyrrolate. Vertical bars are ± SEM. Means are adjusted by analysis of variance (see text). Responses to glycopyrrolate are statistically different from placebo from one half through eight hours after drug administration (p<.05).

Figure 2. Mean percentage of change over time in FVC as percent predicted in patients receiving a single inhaled dose of placebo or glycopyrrolate. Vertical bars are ± SEM. Means are adjusted by analysis of variance (see text). Responses to glycopyrrolate are statistically different from placebo from one half through eight hours after drug administration (p<.05).

[maddison555brooksild]

New Post has been published on All about Asthma

New Post has been published on http://no-asthma.com/ventolin-inhaler-for-treatment-asthma-canadian-healthcare-mall-articles.html

Ventolin Inhaler for Treatment Asthma - Canadian Health&Care Mall articles

The anticholinergic drug atropine produces bronchodilation in patients with asthma; however, systemic side effects limit its clinical usefulness. Quaternary ammonium anticholinergic compounds, such as glycopyrrolate, have fewer side effects than atropine and may be more clinically useful. Previous research suggests glycopyrrolate is an effective bronchodilator in normal subjects and in patients with asthma induced by exercise and cold air. However, the effectiveness of glycopyrrolate in subjects with other forms of asthma has not been evaluated. We studied the effectiveness, optimal dose, and duration of action of glycopyrrolate in patients with nonexercise-induced asthma.

Methods

Patients with clinical asthma were recruited from the practices of the authors and from the community by advertisement Study subjects had mild to moderate obstructive airway disease as defined by a screening FEVj between 30 and 80 percent of predicted. Reversibility was documented by 15 percent or greater improvement in FEV1 after two inhalations of isoproterenol. Subjects were excluded if they had emphysema, bronchiectasis, cystic fibrosis, heart failure, or if they were receiving oral corticosteroid therapy. No patients with chronic bronchitis were included. No patients were receiving cromolyn sodium. Long-acting theophylline preparations were stopped 24 hours before and ventolin inhalers and other bronchodilators 12 hours before screening spirometry and before each study day. The study was approved by the institutional committee on human research and informed consent was obtained from each subject.

A water seal survey spirometer was used to measure FEV1 and FVC. Values were calculated with a microprocessor. The highest values from three forced expirations were used for comparisons. Subjects were studied on five separate occasions, three to 18 days apart. All studies began between 7:30 am and 10:00 am. Spirometry was done twice prior to drug administration to obtain baseline values and to ensure that FEV1 values for each subject were between 30 and 80 percent of predicted values on the day of the study. If a subject s FEV, values did not foil within the required range, or if the subject had symptoms of a respiratory tract infection, the tests were rescheduled. Asthma is a disease treated by ventolin inhalers which may be purchased with the help of buy-asthma-inhalers-online.

At the beginning of each study day, either placebo or glycopyrrolate was administered as two consecutive metered inhalations from an aerosol-generating cannister. On any given study day, a subject received either placebo or 100 μg, 200 μg, 600 μg or 1,200 μg of drug in a random order so that each subject over the course of the study received placebo and all doses of glycopyrrolate. The above doses of glycopyrrolate were chosen because a previous study of normal subjects showed a progressive increase in airway conductance in response to glycopyrrolate doses ranging from 100 to 1,600 μg.

After drug administration, spirometry was performed at 30 minutes, hourly through eight hours, and again at ten and 12 hours. Pulse and blood pressure were recorded, and patients were questioned about drug side effects at each interval. An ECG was obtained before and after each study session and rhythm strips were done two, foui; six, and 12 hours after drug administration. Neither patient nor the investigator knew what the patient received on each day until the entire study was completed.

Spirometry results were expressed as change in percent predicted values as shown in the following formula:

The pretreatment value was the mean of the two baseline values for the study day. The percent predicted measure was chosen to limit the effects of age, height, and weight differences on the results and to avoid the potential bias in percentage of change from baseline measures. Predicted values were calculated according to Morris et al. The FEV1 and FVC were analyzed for differences among glycopyrrolate doses and placebo using analysis of variance (AN OVA) in a General Linear Model (GLM) format. In addition to dose, factors included in the model were FEV1 or FVC baseline on each respective study day and subject number (to adjust for repeated measures). Differences among specific doses were examined using dose specific least square means and pooled standard error.

[cannabis-alchemist-blog-blog]

Quote:  Acetycholine is responsible for maintaining muscle tone of the airways and also contributes to contractions in asthma attacks. Interestingly, asthma medications block the same molecule, but from a slightly different angle.

“They prevent the acetycholine from binding to its receptor,” explains Dr. Donald Tashkin, who was not involved with the study. “But THC works proximal to that. It doesn’t have any competitive effect for binding to receptors. It just prevents the acetylcholine from being released.”

Dr. Donald Tashkin, a lung expert and professor of medicine at UCLA, was part of the team that first discovered marijuana’s effect as a bronchodilator. In 1973, his group published a study in the New England Journal of Medicine that found airways widen in both healthy and asthmatic individuals after smoking marijuana.

“It also succeeded in reversing experimentally induced asthma, in a manner that was comparable to what could be achieved with a standard therapeutic bronchodilator that was widely used at the time.”

[cannabis-alchemist-blog-blog]

Quote: 

Conclusions and Implications

Activation of prejunctional CB1 receptors mediates the inhibition of EFS-evoked cholinergic contraction in human bronchus. This mechanism may explain the acute bronchodilation produced by marijuana smoking.