levothyroxine-sodium and Aminophylline extended release Interactions

Interactions between levothyroxine-sodium(levothyroxine) and Aminophylline extended release (aminophylline)

levothyroxine and aminophylline (Moderate Drug-Drug)

MONITOR: The metabolism of theophylline is directly related to thyroid function. Theophylline clearance is decreased in hypothyroid patients and increased in hyperthyroid patients. Toxicity or subtherapeutic levels may occur. Similar interactions may occur with other methylxanthines.

MANAGEMENT: When thyroid hormone dosage is instituted, discontinued, or changed, close observation for altered theophylline effect and serum concentrations is recommended. Patients should be advised to notify their physician if they experience a worsening of their respiratory symptoms, or any signs of theophylline toxicity including nausea, vomiting, diarrhea, headache, restlessness, insomnia, or irregular heartbeats.