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.