Since its discovery as component of the tea leaf by Albert Kossel in 1888, the history of theophylline (CAS 58-55-9) has been a long and successful one. At the turn of the century, theophylline became less expensive due to chemical synthesis and was primarily used as diuretic in subsequent years. It was Samuel Hirsch who discovered the bronchospasmolytic effect of theophylline in 1992, however, despite this pioneering discovery theophylline continued to be used primarily as diuretic and cardiac remedy. The molecular mechanism of bronchodilatation is inhibition of phosphodiesterase(PDE)3 and PDE4, but the anti-inflammatory effect may be due to histone deacetylase (HDAC) activation, resulting in switching off of activated inflammatory genes. Theophylline is indicated for the treatment of acute exacerbations of the symptoms and reversible airflow obstruction associated with asthma and other chronic lung diseases, e.g., emphysema and chronic bronchitis.

Since its discovery as component of the tea leaf by Albert Kossel in 1888, the history of theophylline (CAS 58-55-9) has been a long and successful one. At the turn of the century, theophylline became less expensive due to chemical synthesis and was primarily used as diuretic in subsequent years. It was Samuel Hirsch who discovered the bronchospasmolytic effect of theophylline in 1992, however, despite this pioneering discovery theophylline continued to be used primarily as diuretic and cardiac remedy. The molecular mechanism of bronchodilatation is inhibition of phosphodiesterase(PDE)3 and PDE4, but the anti-inflammatory effect may be due to histone deacetylase (HDAC) activation, resulting in switching off of activated inflammatory genes. Theophylline is indicated for the treatment of acute exacerbations of the symptoms and reversible airflow obstruction associated with asthma and other chronic lung diseases, e.g., emphysema and chronic bronchitis.

Epinephrine is a sympathomimetic catecholamine. It acts as a naturally occurring agonist at both alpha and beta-adrenergic receptors. Three pharmacologic types have been identified: alpha 1-, alpha 2-, and beta-adrenergic receptors. Each of these has three subtypes, characterized by both structural and functional differences. The alpha 2 and beta receptors are coupled negatively and positively, respectively, to adenylyl cyclase via Gi or Gs regulatory proteins, and the alpha 1 receptors modulate phospholipase C via the Go protein. Subtype expression is regulated at the level of the gene, the mRNA, and the protein through various transcriptional and postsynthetic mechanisms. Through its action on alpha-adrenergic receptors, epinephrine lessens the vasodilation and increased vascular permeability that occurs during anaphylaxis, which can lead to loss of intravascular fluid volume and hypotension. Through its action on beta-adrenergic receptors, epinephrine causes bronchial smooth muscle relaxation and helps alleviate bronchospasm, wheezing and dyspnea that may occur during anaphylaxis. Epinephrine also alleviates pruritus, urticaria, and angioedema and may relieve gastrointestinal and genitourinary symptoms associated with anaphylaxis because of its relaxer effects on the smooth muscle of the stomach, intestine, uterus and urinary bladder. Epinephrine increases glycogenolysis, reduces glucose up take by tissues, and inhibits insulin release in the pancreas, resulting in hyperglycemia and increased blood lactic acid.

Fenoterol is a beta2-adrenoreceptor agonist, used as a bronchodilator for the treatment and prevention of bronchospasms, associated with asthma and chronic obstructive airway disease, including bronchitis and pulmonary emphysema. Fenoterol is also used for tocolysis during premature labor. Marketing of fenoterol for treatment of asthma was suspended in Australia and New Zealand because of an increased risk of deaths, most likely due to excessive self-administration of the drug.

Acefylline is a stimulant drug of the xanthine chemical class. It acts as an adenosine receptor antagonist. Acephylline piperazine is a theophylline derivative with a direct bronchodilator action. It has the advantages over theophylline in being far less toxic and producing minimal gastric irritation. It is indicated for the treatment of asthma, emphysema, acute and chronic bronchitis associated with bronchospasm.Acefylline relaxes smooth muscles, relieves bronchospasm & has a stimulant effect on respiration. It stimulates the myocardium & central nervous system, decreases peripheral resistance & venous pressure & causes diuresis. The mechanism of action is still not clear, inhibition of phosphodiesterase with a resulting increase in intracellular cyclic AMP does occur, but not apparently at concentrations normally used for clinical effect. Other proposed mechanisms of action include adenosine receptor antagonism, prostaglandin antagonism & effects on intracellular calcium. Sodium phenobarbital is a non-selective central nervous system depressant that is primarily used as sedative-hypnotic.

Oxitropium bromide (trade names Oxivent, Tersigan) is a bronchodilator indicated for asthma and chronic obstructive pulmonary disease. Oxitropium’s bronchodilation effect is similar to that of ipratropium bromide, but oxitropium is longer-lasting. The usual dose is 200 ug, 2–3 times daily. It blocks the muscarinic cholinergic receptors which mediate smooth muscle contraction in the airways. The manufacturer claims that regular use of oxitropium (200μg twice or three times daily) reduces the incidence of symptoms, including the need for night-time bronchodilators, and improves lung function in some patients; it is not intended for immediate symptom relief. Although widely used for many years (alone or in combination with short-acting beta agonists) for both maintenance treatment of stable disease and exacerbation of airway obstruction, Boehringer Ingelheim announced the discontinuation of Oxivent formulations at May 2004.

Acefylline is a stimulant drug of the xanthine chemical class. It acts as an adenosine receptor antagonist. Acephylline piperazine is a theophylline derivative with a direct bronchodilator action. It has the advantages over theophylline in being far less toxic and producing minimal gastric irritation. It is indicated for the treatment of asthma, emphysema, acute and chronic bronchitis associated with bronchospasm.Acefylline relaxes smooth muscles, relieves bronchospasm & has a stimulant effect on respiration. It stimulates the myocardium & central nervous system, decreases peripheral resistance & venous pressure & causes diuresis. The mechanism of action is still not clear, inhibition of phosphodiesterase with a resulting increase in intracellular cyclic AMP does occur, but not apparently at concentrations normally used for clinical effect. Other proposed mechanisms of action include adenosine receptor antagonism, prostaglandin antagonism & effects on intracellular calcium. Sodium phenobarbital is a non-selective central nervous system depressant that is primarily used as sedative-hypnotic.