Question

You are talking to one of your colleagues from surgery. He tells you about a postoperative patient that he is covering who keeps complaining of pain. He tells you that the patient was originally on intramuscular meperidine and was switched to the same dose of oral meperidine just yesterday. The patient has been complaining constantly and is getting the nursing staff upset. What do you think is responsible for this situation?

A. The patient has low pain tolerance
B. The patient has borderline personality disorder and is splitting the staff
C. The patient has an intractable pain disorder
D. The analgesic potency of oral meperidine is less than that of intramuscular meperidine
E. The patient has a conversion disorder (functional neurological symptom disorder)

Answer 1

The patient's increased pain after switching from intramuscular to oral meperidine is likely due to the reduced analgesic potency of oral meperidine because of first-pass metabolism. Therefore, the correct option is D.

Step-by-step explanation:

The situation described where a patient is complaining of pain after being switched from intramuscular meperidine to oral meperidine is likely due to the fact that the analgesic potency of oral meperidine is less than that of intramuscular meperidine. When medications are administered orally, they pass through the digestive system and are metabolized by the liver before entering the systemic circulation, a phenomenon known as first-pass metabolism. This process can significantly reduce the amount of drug that reaches the site of action as compared to intramuscular administration. Hence, the same dose given orally does not provide the same pain relief as when it is given intramuscularly. Adjusting the dosage or administration route might be necessary to manage the patient's pain effectively.