Although the exact mechanism is not known, theophyllines may alter the calcium levels of smooth muscle, blocking adenosine receptors, inhibiting the effect of prostaglandins on smooth muscle, and inhibiting the release of slow-reacting substance of anaphylaxis and histamine. Well absorbed from uncoated plain tablets and PO liquids.
Theophylline is metabolized partially to caffeine in the neonate.
Respiratory stimulant in neonatal apnea and Cheyne-Stokes respiration. Use during lactation may result in irritability, insomnia, and fretfulness in the infant. Use with caution in premature infants due to the possible accumulation of caffeine. Xanthines are not usually tolerated by small children because of excessive CNS stimulation. Geriatric clients may manifest an increased risk of toxicity.