Proxyphylline is a xanthine derivative that acts as a cardiac stimulant, vasodilator and bronchodilator. In combination with ephedrine it’s used for relief of acute bronchial asthma and for reversible bronchospasm associated with chronic bronchitis and emphysema. Proxyphylline is readily absorbed from the gastrointestinal tract and it’s not converted to theophylline in the body. The clinical studies are agreed with the property of proxyphylline to inhibit the cyclic nucleotide phosphodiesterases.

Carbuterol is a beta-adrenergic bronchodilator with selectivity for bronchial smooth muscle relative to cardiac and vascular tissues of several species including man. In vitro studies demonstrated that carbuterol was a direct acting beta-adrenergic agonist, not dependent on endogenous catecholamine release, and was devoid of alpha-adrenergic agonist activity. The activity of the racemate was shown to reside primarily in the l-enantiomer. Carbuterol inhibited immunologically induced release of histamine and slow reacting substance of anaphylaxis from passively sensitized fragmented rhesus monkey lung and also inhibited passive cutaneous anaphylaxis in rats. Acute toxicity studies in mice, rats and guinea pigs indicated a wide safety margin for carbuterol. Carbuterol is a safer and more effective bronchodilator than ephedrine.

Trimetoquinol hydrochloride dilates bronchial muscle selectively by stimulating Beta 2-receptors. It is used for the relief of bronchoconstriction associated with bronchitis, asthmatic bronchitis and bronchial asthma. Since the concurrent use of the drug with catecholamines such as Epinephrine and Isoproterenol may induce arrythmia or cardiac arrest in some cases, concurrent use is not recommended. Adverse reactions : Palpitation may occur occasionally, and alteration of blood pressure and precordial pain may appear rarely; headache may occur occasionally; tremor, dizziness, feverish sensation may also be encountered in a rare incidence; occasionally, nausea and anorexia may appear.

Seratrodast belongs to a class of medication called thromboxane A2/prostaglandin endoperoxide receptor antagonist. Seratrodast blocks the broncho-constrictor effects of certain chemicals (prostaglandins) in the body. Seratrodast also decreases the inflammation by antagonising the thromboxane A2 receptor. Adverse effects include gastrointestinal disturbances, drowsiness, headache, palpitations, and hepatitis. Seradair may interact with Ozagrel.

Fenspiride is an oxazolidinone spiro compound used as a drug in the treatment of certain respiratory diseases. It is approved for use in Russia for the treatment of acute and chronic inflammatory diseases of ENT organs and the respiratory tract (like rhinopharyngitis, laryngitis, tracheobronchitis, otitis and sinusitis), as well as for maintenance treatment of asthma. Fenspiride is marketed under the brand names Eurespal, Pneumorel, SYRESP, Oxofen and others. Erespal (fenspiride) is a drug with a bronchodilator and spasmolytic effect, which is often used in the complex therapy of bronchial asthma. Fenspiride has a clinically proven ability to increase the activity of the cilia of the bronchial ciliated epithelium, normalize the secretion of the bronchi and reduce its viscosity. Effectively removes bronchial obstruction, restores pulmonary gas exchange. Inhibits the metabolism of arachidonic acid, in parallel blocking histamine H1-receptors, since it is histamine that stimulates the chemical reactions of the transformation of arachidonic acid into the final metabolites-factors of inflammation. Reduces the production of other mediators of inflammation - serotonin and bradykinin. It blocks α-adrenergic receptors, the activation of which increases the secretion of bronchial glands. The complex effect of fenspiride reduces the pathological effect of a number of factors that promote hypersecretion of anti-inflammatory substances and cause obstruction of the bronchial tree. Has a pronounced antispasmodic and myotropic effect.

Fluticasone is a medium-potency synthetic trifluorinated corticosteroid which is used in some countries to manage nasal symptoms of allergic and non-allergic rhinitis. Fluticasone binds and activates glucocorticoid receptor, resulting in the activation of lipocortin. Lipocortin, in turn, inhibits cytosolic phospholipase A2, which triggers a cascade of reactions involved in the synthesis of inflammatory mediators, such as prostaglandins and leukotrienes. Both the furoate and propanoate esters, fluticasone furoate and fluticasone propionate, are much more commonly used as topical anti-inflammatories and inhaled corticosteroids.

Ambroxol, a substituted benzylamine, is an active metabolite of bromhexine, which is itself a synthetic derivative of vasicine, the active principle extracted from the plant species Adhatoda vasica. Ambroxol is an expectorant exerting mucokinetic properties, mucociliary activity, stimulation of surfactant production, anti-inflammatory and antioxidative actions and the local anaesthetic effect. Ambroxol was discovered at and has been manufactured by Dr. Karl Thomae GmbH, a division of Boehringer Ingelheim. The ambroxol patent is expired and the drug is available as a generic product from many different companies. Ambroxol was originally developed by Boehringer Ingelheim as a OTC therapy for respiratory disorders related to excessive mucus. Ambroxol's indication is secretolytic therapy in acute and chronic bronchopulmonary diseases associated with abnormal mucus secretion and impaired mucus transport. Boehringer Ingelheim markets the product under various brand names such as Mucosolvan® and Lasolvan®. Ambroxol was identified and found to be a pH-dependent, mixed-type inhibitor of glucocerebrosidase (GCase). Its inhibitory activity was maximal at neutral pH, found in the endoplasmic reticulum, and undetectable at the acidic pH of lysosomes. The pH dependence of Ambroxol to bind and stabilize the enzyme was confirmed. Ambroxol increases both the lysosomal fraction and the enzymatic activity of several mutant GCase variants. This profile of Ambroxol would allow to bind and stabilize GCase in the endoplasmic reticulum (thus preventing its degradation within endoplasmic reticulum), but without affecting GCase in the lysosomes (thus allowing it to degrade glucosylceramide). Indeed, studies showed that Ambroxol treatment significantly increased N370S and F213I mutant GCase activity and protein levels in fibroblasts originally obtained from Gaucher patients. Gaucher's disease is caused by the deficiency of glucocerebrosidase; ambroxol is a chaperone that acts by binding to and stabilising glucocerebrosidase. Zywie (formerly ExSAR Corporation) and Belrose Pharma are developing ambroxol hydrochloride (BEL 0218) for the treatment of type III Gaucher's disease. .

Eprozinol inhibits bronchoconstriction by an action on histamine H1 receptors and has been used in the treatment of asthma and bronchitis. No significant changes in cAMP and cGMP levels are observed in guinea pig trachea, with eprozinol or isoprenaline, at doses capable of inducing relaxation. Eprozinol is only a very weak phosphodiesterase inhibitor, at large concentrations. The anti-bronchoconstrictor activities of eprozinol and isoprenaline with regard to histamine are directly additive and show absolutely no interference with one another. Propranolol is without effect on in vivo anti-bronchoconstrictor activity of eprozinol on tracheal musculature. It is concluded, that the mechanisms brought into play by eprozinol to exert anti-bronchoconstrictor and bronchorelaxant activity, are completely independent of the adrenergic system. In a retrospective study of 199 cases of accidental or intentional acute poisoning with eprozinol, eprazinone and zipeprol, collected at the Poison Control Center were seven cases of seizures, all after ingestion of eight times the therapeutic dose. They resolved rapidly and without recurrence with symptomatic treatment.

Ibudilast (KETAS®) is a non-selective cyclic nucleotide phosphodiesterase (PDE) inhibitor. It is an antithrombotic, antiasthmatic drug that is used for improving prognosis and relieving symptoms in patients suffering from ischemic stroke and for the treatment of bronchial asthma. A definitive mechanism of its action is yet to be established. However, inhibition of the release of inflammatory cytokines, inhibition of leukocyte activation, and inhibition of the expression of cell adhesion molecules have been proposed as likely mechanisms of action of ibudilast (KETAS®). It is currently in development in the US (for instance as a potential therapy for multiple sclerosis), but is approved for use in Japan.

Pranlukast is an antagonist of cysteinyl leukotriene receptor-1 antagonist. It is marketed in Japan by Ono Pharmaceuticals under trademark ONON for the treatment of bronchial asthma and allergic rhinitis as capsules and dry syrup for pediatric use.