Ipratropium bromide: a review of its pharmacological properties and therapeutic efficacy in asthma and chronic bronchitis

Ipratropium bromide is an anticholinergc bronchodilator administered by inhalation. Although producing bronchodilation in most patients with obstructive airways disease, it is somewhat less effective than beta 2-adrenoceptor agonist drugs such as salbutamol or fenoterol in patients with asthma, but is at least as effective as these agents in bronchitis. As with the beta 2-adrenoceptor agonists, the onset of maximum effect with ipratropium (about 1.5 to 2 hours) is slower than with isoprenaline (although significant bronchodilation usually occurs within seconds or minutes of ipratropium inhalation), and the duration of effect (about 4 to 6 hours) is longer. Studies of concomitant use of ipratropium and other agents such as beta 2-adrenoceptor agonists, theophylline, or sodium cromoglycate, have usually shown a greater response in many patients than with single drug therapy, as might be expected from the different mechanisms of action of these groups of drugs. Usual inhaled doses of ipratropium were well tolerated in all studies. Ipratropium thus appears to be a suitable alternative to beta 2-adrenoceptor agonist drugs in patients not fully responding to these agents, and combined therapy with ipratropium and other bronchodilating drugs may prove to be an important area of use in patients failing to respond adequately to a single drug regimen. (nevertheless, in asthma patients in whom a 'non-responsive' state is developing, initiation of corticosteroid therapy should not be delayed). Ipratropium may also be useful in the occasional patient in whom side effects such as palpitations or tremor are troublesome with usual inhaled doses of beta 2-adrenoceptor agonists.

Tiotropium bromide (Ba 679 BR), a novel long-acting muscarinic antagonist for the treatment of obstructive airways disease

Tiotropium bromide (Ba 679 BR) is a novel potent and long-lasting muscarinic antagonist that has been developed for the treatment of chronic obstructive airways disease (COPD). Binding studies with [3H]tiotropium bromide in human lung have confirmed that this is a potent muscarinic antagonist with equal affinity for M1-, M2- and M3-receptors and is approximately 10-fold more potent than ipratropium bromide. Tiotropium bromide dissociates very slowly from lung muscarinic receptors compared with ipratropium bromide. In vitro tiotropium bromide has a potent inhibitory effect against cholinergic nerve-induced contraction of guinea-pig and human airways, that has a slower onset than atropine or ipratropium bromide. After washout, however, tiotropium bromide dissociates extremely slowly compared with the dissociation of atropine and ipratropium bromide. Measurement of acetylcholine (ACh) release from guinea-pig trachea shows that tiotropium bromide, ipratropium bromide and atropine all increase ACh release on neural stimulation and that this effect is washed out equally quickly for the three antagonists. This confirms binding studies to transfected human muscarinic receptors which suggested that tiotropium bromide dissociates slowly from M3-receptors (on airway smooth muscle) but rapidly from M2 autoreceptors (on cholinergic nerve terminals). Clinical studies with inhaled tiotropium bromide confirm that it is a potent and long-lasting bronchodilator in COPD and asthma. Furthermore, it protects against cholinergic bronchoconstriction for > 24 h. This suggests that tiotropium bromide will be a useful bronchodilator, particularly in patients with COPD, and may be suitable for daily dosing. The selectivity for M3- over M2-receptors may also confer a clinical advantage.

Direct labelling of ipratropium bromide aerosol and its deposition pattern in normal subjects and patients with chronic bronchitis

A technique for the direct labelling of ipratropium bromide with bromine-77, with reconstitution of the drug in a metered dose inhaler so as to be identical to the commercial product, was used to study drug deposition patterns in seven normal subjects and seven patients with chronic bronchitis (mean FEV1 32% (SD 12.2%) predicted normal). The gamma camera image of the thorax was divided into a middle zone--the mediastinal zone--and the lung itself into a central zone comprising its medial third and a peripheal zone, the lateral two thirds. Measurements after 10 inhalations of labelled ipratropium bromide showed similar results for the two groups of subjects. The total lung dose inhaled was 11.2% of 203 micrograms and 11.7% of 186 micrograms in the normal subjects and the patients respectively. In contrast to the deposition patterns seen in aerosol studies using steady state inhalation methods, there was no difference in deposition pattern--that is, the distribution between the central and the peripheral lung zones--between the normal subjects and the patients with airways obstruction.

Organic cation transporter-mediated renal secretion of ipratropium and tiotropium in rats and humans

Ipratropium bromide (ipratropium) and tiotropium bromide (tiotropium), anticholinergic agents with bronchodilating properties, are used to treat patients with chronic obstructive pulmonary disease. Because they are actively secreted into urine, the interaction of these agents with organic cation transporters (OCTs/Octs) was examined in rat kidney slices and in cultured cells expressing rat Oct (rOct) or human OCT (hOCT). Uptake of radiolabeled ipratropium in rat kidney slices was significantly inhibited by OCT/Oct substrates including cimetidine, imipramine, and quinidine, but not by organic anion transporter substrates (e.g., p-aminohippuric acid and estrone-3-sulfate). [(3)H]Tiotropium uptake showed similar characteristics. Reverse transcription-polymerase chain reaction showed that, in rat kidney, mRNA expression of rOct2 was the highest, followed by rOct1, but little rOct3 was detected. In vitro, rOct1 and rOct2 transported both anticholinergics, but rOct3 accepted only ipratropium. Ipratropium uptake by rat kidney slices consisted of two components with K(m) values of 0.114 ± 0.06 and 24.5 ± 2.21 μM. The K(m) value of rOct2-mediated ipratropium uptake (0.143 ± 0.03 μM) was consistent with that of the high-affinity component. The OCT/Oct inhibitor corticosterone, at a concentration of 1 μM (IC(50), 1.11 ± 0.20 μM for rOct2-mediated ipratropium transport), inhibited ipratropium by 18.4%, suggesting that rOct2 is involved in renal secretion of ipratropium. In a similar manner, ipratropium and tiotropium were taken up by cultured cells expressing hOCT1 and hOCT2 but not hOCT3. We conclude that OCT2/Oct2 plays a role in renal secretion of both anticholinergics in these species. Coadministration of these anticholinergics with cationic drugs recognized by OCT2/Oct2 may decrease renal clearance, resulting in increased systemic exposure.

Clinical pharmacology and toxicology of ipratropium bromide

Anticholinergic drugs inhibit a variety of intrapulmonary events related to airflow obstruction. When administered as an inhaled aerosol, approximately 90 percent of ipratropium bromide (as with beta-adrenergic aerosols) can be assumed to be swallowed. Peak pharmacologic effects occur prior to any detectable plasma drug concentrations. Ipratropium does not exhibit the well-known toxic effects of atropine, and doses many times those required for maximum therapeutic benefit do not produce any effects on the eye, urinary bladder, heart rate, or mucociliary function. Ipratropium seems to act primarily on large- and intermediate-size airways; beta-adrenergic agents, on the other hand, appear to act primarily on the smaller airways. The drug is a promising addition to the therapeutic armamentarium, and may be especially useful in certain groups of patients whose condition is less responsive to other agents.

Tropane alkaloids as substrates and inhibitors of human organic cation transporters of the SLC22 (OCT) and the SLC47 (MATE) families

Tropane alkaloids and their derivatives are anticholinergic drugs with narrow therapeutic range. Here we characterize the organic cation transporters from the SLC22 (OCT1, OCT2, and OCT3) and the SLC47 families (MATE1 and MATE2-K) as potential mediators of the renal and extra-renal excretion, the two major roads of elimination of these substances. All analyzed compounds inhibited and the quaternary amine derivatives ipratropium and trospium were strongly transported by OCTs and MATEs. Overexpression of OCTs or MATEs in HEK293 cells resulted in an up to 63-fold increase in the uptake of ipratropium (Km of 0.32 μm to OCT2 and Vmax of 3.34 nmol×mg protein-1×min-1 to MATE1). The transcellular transport of ipratropium was 16-fold higher in OCT2-MATE1 and 10-fold higher in OCT1-MATE1 overexpressing compared to control MDCKII cells. Genetic polymorphisms in OCT1 and OCT2 affected ipratropium uptake and clinically relevant concentration of ondansetron and pyrithiamine inhibited ipratropium uptake via MATEs by more than 90%. This study suggests that OCT1, OCT2 and MATEs may be strongly involved in the renal and extra-renal elimination of ipratropium and other quaternary amine alkaloids. These substances have a notoriously narrow therapeutic range and the drug-drug interactions suggested here should be further critically evaluated in humans.

Radioreceptor assay for determination of the antimuscarinic drug ipratropium bromide in man

A radioreceptor assay for the determination of ipratropium bromide in human plasma has been developed, using [3H] N-methyl-scopolamine as a radioligand to label muscarinic cholinergic receptors in a membrane preparation of rat cerebral cortex. There was no interference due to the cross-reactivity of 3 metabolites of ipratropium with the parent compound (5.2, 1.5 and 0.004%, respectively). The validity of the assay was checked between 20 pg/ml and 1000 pg/ml drug. In a pilot study plasma levels following a single oral dose of 30 mg were determined to examine the applicability of the radioreceptor assay to clinical and pharmacokinetic studies, and for measurement of plasma levels after therapeutic oral doses. The peak plasma concentration in three healthy volunteers (means = 322 pg/ml) occurred within 1-3 h.

Ipratropium bromide

Research clarifying the role of the parasympathetic nervous system in the pathophysiology of chronic obstructive pulmonary disease (COPD) has renewed interest in anticholinergic therapy of these disease processes. The investigational agent ipratropium bromide produces bronchodilation by competitive inhibition of cholinergic receptors on bronchial smooth muscle, antagonizing the action of acetylcholine. When administered via inhalation at therapeutic doses of 20-40 micrograms, ipratropium is somewhat less effective than beta-agonists in asthmatics. In the treatment of chronic bronchitis, however, ipratropium appears at least as effective as, and possibly superior to, the sympathomimetics. Combination therapy with beta-agonists or theophylline has resulted in enhanced effect over single-agent regimens. Due to the low serum concentrations achieved following inhalation, ipratropium has been well tolerated and is virtually free of significant adverse reactions. The primary role of ipratropium in therapy remains to be defined but appears to be as an alternative to beta-agonists in patients who fail to respond or who experience troublesome side effects. In addition, combination therapy may prove to be another important use of ipratropium in the management of COPD.

Combination of ipratropium bromide and salbutamol in children and adolescents with asthma: A meta-analysis

BACKGROUND

A combination of ipratropium bromide (IB) and salbutamol is commonly used to treat asthma in children and adolescents; however, there has been a lack of consistency in its usage in clinical practice.

OBJECTIVE

To evaluate the efficacy and safety of IB + salbutamol in the treatment of asthma in children and adolescents.

METHODS

The MEDLINE, Embase, and Cochrane Library as well as other Chinese biomedical databases (including China Biological Medicine Database, Chinese National Knowledge Infrastructure, Chongqing VIP, and Wanfang Chinese language bibliographic database) were systematically searched from the earliest record date to September 2020 for randomized controlled trials in children and adolescents (≤18 years) with asthma who received IB + salbutamol or salbutamol alone. The primary outcomes included hospital admission and adverse events. A random effects model with a 95% confidence interval (CI) was used. Subgroup analysis was performed according to age, severity of asthma, and co-interventions with other asthma controllers. This study was registered with PROSPERO.

RESULTS

Of the 1061 studies that were identified, 55 met the inclusion criteria and involved 6396 participants. IB + salbutamol significantly reduced the risk of hospital admission compared with salbutamol alone (risk ratio [RR] 0.79; 95% CI 0.66-0.95; p = 0.01; I2 = 40%). Subgroup analysis only showed significant difference in the risk of hospital admission in participants with severe asthma exacerbation (RR 0.73; 95% CI 0.60-0.88; p = 0.0009; I2 = 4%) and moderate-to-severe exacerbation (RR 0.69; 95% CI 0.50-0.96; p = 0.03; I2 = 3%). There were no significant differences in the risk of adverse events between IB + salbutamol group and salbutamol alone group (RR 1.77; 95% CI 0.63-4.98).

CONCLUSION

IB + salbutamol may be more effective than salbutamol alone for the treatment of asthma in children and adolescents, especially in those with severe and moderate to severe asthma exacerbation. The very low to high quality of evidence indicated that future well-designed double-blind RCTs with large sample are needed for research on evaluating the effectiveness of IB + salbutamol treatment for asthma in children and adolescents.

Effects of Different Intervention Factors on Vascular Endothelial Growth Factor-Induced Human Airway Smooth Muscle Cell Migration

Background

Asthma airway remodeling is closely related to the abnormal migration of human airway smooth muscle cells (ASMCs), and vascular endothelial growth factor (VEGF) is involved in the pathophysiological process of asthma. This study aimed to investigate the effect of VEGF on ASMC migration through in vitro cell experiments and to intervene in ASMC migration with different asthma drugs and signaling pathway inhibitors to provide a basis for screening effective drugs for airway remodeling.

Methods

The effect of VEGF on the proliferation of ASMCs was detected by the CCK-8 method, and the effect of VEGF on the migration of ASMCs was proven by scratch and transwell assays. Different asthma drugs and signaling pathway inhibitors were used to interfere with the migration of ASMCs. The number of migrating cells was compared between the intervention and nonintervention groups.

Results

Our results showed that VEGF induction enhanced ASMC migration; pretreatment with the commonly used asthma drugs (salbutamol, budesonide, and ipratropium bromide) significantly attenuated VEGF-induced ASMC migration; and inhibitors SB203580, LY294002, and Y27632 blocked the VEGF-induced activation of p38 MAPK, PI3K, and ROCK signaling pathway targets in ASMCs and inhibited migration.

Conclusion

This study shows that the current commonly used asthma drugs salbutamol, budesonide, and ipratropium have potential value in the treatment of airway remodeling, and the p38 MAPK, PI3K, and ROCK signaling pathway targets are involved in the VEGF-induced ASMC migration process. Signaling pathway inhibitor drugs may be a new way to treat asthma-induced airway remodeling in asthma patients in the future. However, the related mechanism and safety profile still need further research.

Inhalation of Citrus Reticulata essential oil alleviates airway inflammation and emphysema in COPD rats through regulation of macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory respiratory disease. Citrus Reticulata peel, the dried ripe peel of Citrus Reticulata species, has been found to have anti-inflammatory and cough attenuation effects. However, the therapeutic effects and its precise underlying mechanisms of atomizing inhalation using Citrus Reticulata essential oil (CREO) have not yet been fully elucidated.

AIM OF THE STUDY

The aim of this study was to assess the therapeutic effects of Citrus Reticulata essential oil and its associated anti-inflammatory mechanisms in COPD rat model.

METHODS

A total of 80 SD rats were randomized into four groups: control group (Con), COPD model group (COPD), COPD + ipratropium bromide (IB), and COPD + citrus reticulata essential oil (CREO). To induce COPD in rats, cigarette smoke (CS) exposure was used, while CREO and IB groups were administered through atomizing inhalation. The clinical signs, pathological lesions of the lung, percentages of antigen-presenting lung macrophages (CD11b/c+/CD86+ cells) and CD8+ T cells, and the content and mRNA expression of cytokines of the lung were analyzed.

RESULTS

The findings revealed that atomizing inhalation of Citrus reticulata essential oil had therapeutic effects on COPD rats. The treatment resulted in improvement in the body weight and mental status of COPD rats, reduced pathological injury of the lung, and increased proportion of CD11b/c+/CD86+ cells in lung macrophages, while also decreasing the number of CD8+ T cells. In addition, the Citrus Reticulata essential oil reduced the contents of IL-18, IL-17A, IL-12p70, and GM-CSF, downregulated the relative mRNA expression of IFN-γ, IL-4, and MMP-12, and upregulated the mRNA expression of IL-10.

CONCLUSIONS

Citrus reticulata essential oil can alleviate histological injury of the lung and regulate macrophages and CD8+ T cells in COPD rats. The study suggests that citrus reticulata essential oil could be a potential therapeutic agent for COPD.

Pharmacological effects and determination of the morphological distribution of powder aerosols containing fenoterol hydrobromide and ipratropium bromide

The bronchospasmolytic effects of fenoterol hydrobromide and ipratropium bromide, with some cardiovascular side effects by fenoterol, and the topographic morphological distribution of the powder aerosol particles in the respiratory tract were clearly demonstrated with the aid of ethidium-induced fluorescence in anaesthetised dogs.