ADEX Dental Hygiene Licensing Practice Exam Practice Test & Study Guide

The appropriate medication that should not be given to a patient taking theophylline is erythromycin. This is because erythromycin is a strong inhibitor of the cytochrome P450 enzyme system, particularly CYP3A4. Theophylline is metabolized through this system; therefore, when erythromycin is administered, it can significantly increase the plasma concentration of theophylline, leading to an increased risk of theophylline toxicity. Symptoms of toxicity may include nausea, vomiting, insomnia, and in severe cases, seizures and life-threatening arrhythmias.

In contrast, amoxicillin, metformin, and ibuprofen do not have significant interactions with theophylline. Amoxicillin is a penicillin antibiotic used to treat infections and does not interfere with theophylline metabolism. Metformin is an oral hypoglycemic agent used for managing type 2 diabetes and does not affect theophylline levels. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) primarily used for pain relief and inflammation and is also not known to have any direct interaction with theophylline.

Thus, understanding the drug interactions is crucial for safe medication management, especially in patients requiring theophylline therapy for conditions such as asthma or chronic obstructive pulmonary disease (COP