Skeletal formula of 8-phenyltheophylline
Ball-and-stick model of the 8-phenyltheophylline molecule
Clinical data
ATC code
  • None
  • 8-Phenyl-1,3-dimethyl-7H-purine-2,6-dione
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass256.265 g·mol−1
3D model (JSmol)
  • Cn3c(=O)c2nc(c1ccccc1)[nH]c2n(C)c3=O
  • InChI=1S/C13H12N4O2/c1-16-11-9(12(18)17(2)13(16)19)14-10(15-11)8-6-4-3-5-7-8/h3-7H,1-2H3,(H,14,15) checkY
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8-Phenyltheophylline (8-phenyl-1,3-dimethylxanthine, 8-PT) is a drug derived from the xanthine family which acts as a potent and selective antagonist for the adenosine receptors A1 and A2A, but unlike other xanthine derivatives has virtually no activity as a phosphodiesterase inhibitor.[1][2][3] It has stimulant effects in animals with similar potency to caffeine.[4] Coincidentally 8-phenyltheophylline has also been found to be a potent and selective inhibitor of the liver enzyme CYP1A2 which makes it likely to cause interactions with other drugs which are normally metabolised by CYP1A2.[5]

See also


  1. ^ Scotini E, Carpenedo F, Fassina G (February 1983). "New derivatives of methyl-xanthines: effect of thiocaffeine thiotheophylline and 8-phenyltheophylline on lipolysis and on phosphodiesterase activities". Pharmacological Research Communications. 15 (2): 131–43. doi:10.1016/s0031-6989(83)80055-1. PMID 6844374.
  2. ^ Rabe KF, Magnussen H, Dent G (April 1995). "Theophylline and selective PDE inhibitors as bronchodilators and smooth muscle relaxants". The European Respiratory Journal. 8 (4): 637–42. PMID 7664866.
  3. ^ Howell LL, Morse WH, Spealman RD (September 1990). "Respiratory effects of xanthines and adenosine analogs in rhesus monkeys". The Journal of Pharmacology and Experimental Therapeutics. 254 (3): 786–91. PMID 2395111.
  4. ^ Spealman RD (1988). "Psychomotor stimulant effects of methylxanthines in squirrel monkeys: relation to adenosine antagonism". Psychopharmacology. 95 (1): 19–24. doi:10.1007/bf00212759. PMID 3133696. S2CID 11539292.
  5. ^ Murray S, Odupitan AO, Murray BP, Boobis AR, Edwards RJ (March 2001). "Inhibition of human CYP1A2 activity in vitro by methylxanthines: potent competitive inhibition by 8-phenyltheophylline". Xenobiotica; the Fate of Foreign Compounds in Biological Systems. 31 (3): 135–51. doi:10.1080/00498250110043292. PMID 11465391. S2CID 23506958.