Aminophylline - Mechanism of Action

Mechanism of Action

Like other methylated xanthine derivatives, aminophylline is both a

  1. competitive nonselective phosphodiesterase inhibitor which raises intracellular cAMP, activates PKA, inhibits TNF-alpha and leukotriene synthesis, and reduces inflammation and innate immunity and
  2. nonselective adenosine receptor antagonist.

Aminophylline is less potent and shorter-acting than theophylline. Its most common use is in the treatment of bronchial asthma.

Causes bronchodilatation, diuresis, CNS and cardiac stimulation, and gastric acid secretion by blocking phosphodiesterase which increases tissue concentrations of cyclic adenine monophosphate (cAMP) which in turn promotes catecholamine stimulation of lipolysis, glycogenolysis, and gluconeogenesis and induces release of epinephrine from adrenal medulla cells

Adenosine is an endogenous extracellular messenger that can regulate myocardial oxygen needs. It acts through cellular surface receptors which effect intracellular signalling pathways to increase coronary artery blood flow, slow heart rate, block atrioventricular node conduction, suppress cardiac automaticity, and decrease β-adrenergic effects on contractility. Adenosine also antagonizes chronotropic and ionotropic effects of circulating catecholamines. Overall, adenosine decreases the heart’s rate and force of contraction, which increases blood supply to the cardiac muscle. Given specific circumstances this mechanism (which is intended to protect the heart) may cause atropine-resistant refractory bradyasystole. Adenosine’s effects are concentration-dependent. Adenosine’s receptors are competitively antagonized by methylxanthines such as aminophylline. Aminophylline competitively antagonizes the cardiac actions of adenosine at the cell surface receptors. Thus, it increases heart rate and contractility.

Read more about this topic:  Aminophylline

Famous quotes containing the words mechanism of, mechanism and/or action:

    Life is an offensive, directed against the repetitious mechanism of the Universe.
    Alfred North Whitehead (1861–1947)

    When one of us dies of cancer, loses her mind, or commits suicide, we must not blame her for her inability to survive an ongoing political mechanism bent on the destruction of that human being. Sanity remains defined simply by the ability to cope with insane conditions.
    Ana Castillo (b. 1953)

    Suit the action to the word, the word to the action, with this special observance, that you o’erstep not the modesty of nature.
    William Shakespeare (1564–1616)