Theolair
Generic name:theophylline
Dosage form: tablets
Drug class:Methylxanthines
Medically reviewed by Drugs.com. Last updated on Jul 22, 2021.
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(theophylline tablets USP)
TABLETS
The Theolair brand name has been discontinued in the U.S. If generic versions of this product have been approved by the FDA, there may be generic equivalents available.
Theolair Description
Theophylline is structurally classified as a methylxanthine. It occurs as a white, odorless, crystalline powder with a bitter taste. Anhydrous theophylline has the chemical name 1H-Purine-2,6-dione, 3,7-dihydro-1,3-dimethyl-, and is represented by the following structural formula:
The molecular formula of anhydrous theophylline is C7H8N4O2 with a molecular weight of 180.17. Theolair Tablets contain 125 mg or 250 mg of theophylline anhydrous intended for oral administration. Theolair Tablets also contain: colloidal silicon dioxide, lactose, magnesium stearate, and pregelatinized starch.
Theolair - Clinical Pharmacology
Mechanism of Action:
Theophylline has two distinct actions in the airways of patients with reversible obstruction: smooth muscle relaxation (i.e., bronchodilation) and suppression of the response of the airways to stimuli (i.e., non-bronchodilator prophylactic effects). While the mechanisms of action of theophylline are not known with certainty, studies in animals suggest that bronchodilatation is mediated by the inhibition of two isozymes of phosphodiesterase (PDE III and, to a lesser extent, PDE IV) while non-bronchodilator prophylactic actions are probably mediated through one or more different molecular mechanisms, that do not involve inhibition of PDE III or antagonism of adenosine receptors. Some of the adverse effects associated with theophylline appear to be mediated by inhibition of PDE III (e.g., hypotension, tachycardia, headache, and emesis) and adenosine receptor antagonism (e.g., alterations in cerebral blood flow).
Theophylline increases the force of contraction of diaphragmati...
