A nurse is administering a daily dose of vancomycin at 10:00 AM. At which time should the nurse obtain the patient's blood sample to determine the trough level?

A. Discoloration of teeth: Tetracycline antibiotics can bind with calcium ions in teeth, leading to the development of yellow-gray-brown stains. This effect is particularly significant in developing teeth in children below the age of 8 and can result in permanent discoloration.

B. Anabolic change: This term doesn't specifically relate to the side effects of tetracycline. "Anabolic" generally refers to processes in the body that build up complex molecules from simpler ones. There's no direct connection between tetracycline and anabolic changes.

C. Cartilage damage: Tetracyclines, especially in high doses or with prolonged use, have been associated with potential adverse effects on cartilage. This is more relevant in individuals whose bones and cartilage are still growing, such as children. It can interfere with skeletal development.

D. Suppression of growth: Long-term use of tetracycline in children can interfere with bone growth and development. It can suppress the growth of bones and affect overall height. This is a significant concern when considering the use of tetracycline in pediatric patients.

A. "This drug has a longer duration of action than some of the other antibiotics."
Explanation: Azithromycin, a macrolide antibiotic, has a longer half-life in the body compared to some other antibiotics. Half-life refers to the time it takes for half of the drug to be eliminated from the body. A longer half-life means the drug remains effective for a longer duration, allowing for less frequent dosing.

B. "This is a much more effective drug than what you received previously."
Explanation: While azithromycin is effective against a wide range of bacterial infections, it's not accurate to say it's universally more effective than other antibiotics. The choice of antibiotic depends on the specific type of infection and the susceptibility of the bacteria causing it. Effectiveness varies based on the context of use.

C. "I'll call the pharmacy and ask about the chemical makeup of the drug."
Explanation: While understanding the chemical makeup of drugs is important for healthcare professionals, it might not directly answer the patient's question about the dosing frequency. Explaining the drug's pharmacological properties, such as its duration of action, would provide a more relevant and understandable response to the patient's query.

D. "You'll need to ask your healthcare provider questions like that."
Explanation: This response does not provide the patient with the information they seek. Nurses are valuable resources for medication-related questions and should strive to provide accurate and understandable explanations to patients.