**Question:** A 32-year-old ex-heroin addict with hepatitis C requires an urgent laparotomy for Rx of a perforated duodenal ulcer. The patient is undergoing treatment with naltrexone. The results of pre-operative coagulation studies include an INR for the prothrombin time of 1.8 and a platelet count of 85,000/cubic mm. Given this scenario, which of the following post-operative analgesic techniques would be most appropriate?

A. Non-opioid analgesics
B. Combination of opioids and non-opioid analgesics
C. Patient-controlled analgesia (PCA) with opioids
D. Spinal or epidural anaesthesia

**Correct Answer:** D. Spinal or epidural anaesthesia

**Core Concept:** In this scenario, we are considering the most appropriate post-operative analgesic technique for a patient with increased coagulation risk due to hepatitis C, undergoing a laparotomy under naltrexone treatment.

**Why the Correct Answer is Right:** Despite the patient's history of heroin addiction and ongoing treatment with naltrexone, spinal or epidural anaesthesia remains a suitable option for providing post-operative analgesia.

Naltrexone is a medication used to treat opiate addiction. However, its primary mechanism of action is blocking the effects of opiates on the opioid receptors, not affecting the coagulation status or platelet count. As the patient's INR (International Normalized Ratio) is 1.8, which is considered normal, and platelet count is 85,000/cubic mm, the coagulation profile indicates a stable haemostatic system. This suggests that the patient is not at an increased risk of bleeding or clotting disorders.

**Why Other Options are Incorrect:**

A. Non-opioid analgesics (e.g., paracetamol, NSAIDs) are less effective for severe abdominal pain due to their limited analgesic effect.

B. Combination of opioids and non-opioid analgesics (e.g., paracetamol and non-steroidal anti-inflammatory drugs) does not address the patient's need for potent analgesia after abdominal surgery.

C. Patient-controlled analgesia (PCA) with opioids is a valid option, but it may cause respiratory depression and other adverse effects due to the patient's history of opiate addiction and treatment with naltrexone.

D. Spinal or epidural anaesthesia provides effective analgesia and avoids the risks associated with opioids, such as respiratory depression and naltrexone-induced adverse effects.

**Clinical Pearl:**

In patients with stable coagulation profiles like this patient, spinal or epidural anaesthesia is a safer and more effective way to manage post-operative pain than oral or systemic opioid administration, especially considering their history of opiate addiction and ongoing naltrexone treatment.

**Explanation of each option:**

A. Non-opioid analges