Non-selective adenosine A1/A2A/A2B antagonist + non-selective PDE inhibitor (PDE3, PDE4 primarily). Drives airway smooth-muscle relaxation and anti-inflammatory histone-deacetylase-2 activation at lower doses. Metabolised primarily by CYP1A2 + CYP3A4 — highly interaction-prone (fluvoroquinolones, macrolides, cimetidine all raise levels).
Half-Life (t½)
PO: 8h, IV: 8h
Dosing Guidelines
PO: Typical 11.7 mcg (Range: 10–15 mcg)
IV: Typical 11.7 mcg (Range: 10–15 mcg)
Target Organ Systems
nervous
respiratory
digestive
immune-hematologic
Interactions
Caffeine (caution): Theophylline inhibits CYP1A2 (IC50 ≈ 120 µM, Murray 2001, used here as a Ki approximation for competitive inhibition near substrate Km) — slows caffeine clearance; concurrent use stacks tachycardia + anxiety.