Theobromine

Category: alkaloid

Aliases: 3,7-Dimethylxanthine

Pharmacological Mechanism

Methylated xanthine found in cocoa. Weaker adenosine A1/A2A antagonist than caffeine (A2A Ki ~14 µM vs caffeine's ~2.4 µM) and weaker PDE inhibitor. Longer plasma t½ (~7 h vs caffeine's ~5 h). Mild vasodilator. Highly toxic to dogs + cats (slow xanthine metabolism in those species).

Half-Life (t½)

PO: 7.1h

Dosing Guidelines

• PO: Typical 117mg (Range: 50 - 250 mg)

Target Organ Systems

• nervous
• cardiovascular

Interactions

• Caffeine