Pharmacology The following statements regarding methylxanthines are true except: A It enhances the receptor - mediated actions of adenosine B It can enhance water and electrolyte excretion C It can relax bronchial smooth muscles D Long-term ingestion can produce tolerance and physical dependence 💡 Explanation The following statements regarding methylxanthines are true except: ✓ Correct Answer: A. It enhances the receptor - mediated actions of adenosine