Theophylline

Category: alkaloid

Aliases: 1,3-Dimethylxanthine, Theo-24, Elixophyllin

Pharmacological Mechanism

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 11.7mcg (Range: 10 - 15 mcg)
• IV: Typical 11.7mcg (Range: 10 - 15 mcg)

Target Organ Systems

• nervous
• respiratory
• digestive
• immune-hematologic

Interactions

• Caffeine