Adenosine Receptor Antagonist

Answer: c

Theophylline binds non-selectively to phosphodiesterase enzyme, inhibits it and increases cAMP levels, activates PKA, inhibits TNF α, inhibits leukotriene synthesis thus reduces inflammation and innate immunity.

Theophylline also binds non-selectively to adenosine receptors acting as adenosine antagonist at A1, A2 and A3 receptors almost equally and thus produces cardiac effects.