Theophylline dyphylline 7-dihydroxypropyl

Dyphylline [l,3-dimethyl-7-(2, 3-dihydroxypropyl)xan-thine] and theophylline inhibit cyclic nucletide PDFs, thereby preventing breakdown of cyclic AMP and cyclic GMP to 5 -AMP and 5 -GMP, respectively. Inhibition of PDFs will lead to an accumulation of cAMP and cGMP, thereby increasing signal transduction through these pathways. The cyclic nucleotide PDFs are members of a superfamily of genetically distinct enzymes. Theophylline and related methylxanthines are relatively nonselective in the PDF subtypes they inhibit. 

Dyphylline is the N-7 dihydroxypropyl derivative of theophyiiine and is not a theophylline salt. Dyphylline does not get metabolized to theophylline in vivo, and even though it contains 70% theophylline by molecular weight ratio, the equivalent amount to theophylline is not known. Dosing must be accomplished independently by monitoring dyphylline blood levels. Dyphylline has a diminished bronchodilator effect compared to theophylline, but it may have lower and less serious side effects. Dosage forms available are an elixir and tablets. 

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