Answer to Question 1
ANS: B
The administration of both isoniazid and rifampin is an effective means of treating tuberculosis, and giving them both reduces the dosages of each individually, minimizing the risk of hepatotoxicity.
Although both rifampin and isoniazid are hepatotoxic, there is no indication that the patient is hepatotoxic, therefore there is no need to question the order.
Because both isoniazid and rifampin can lead to hepatotoxicity, alcohol should be avoided by the patient.
Collecting a sputum culture is part of the diagnostic process for tuberculosis and would have been done before the medications were order and started.
Answer to Question 2
ANS: B, C, E
The combination of theophylline and caffeine cause excitation when given concurrently; the combination of spironolactone and salt substitutes can cause very high potassium levels, which can affect the heart; grapefruit juice intensifies the effects of midazolam, resulting in increased sedation.
Lovastatin and grapefruit juice have interactions that result in increased blood levels of Mevacor; however, lovastatin and orange juice do not have this interaction. Maalox and grapefruit juice are not contraindicated and do not result in a drug and food interaction.