Which intrathecal morphine dose provides analgesia similar to epidural 10 mg morphine?

Which intrathecal morphine dose provides analgesia similar to epidural 10 mg morphine?

• A. 0.1 mg
• B. 1 mg
• C. 5 mg
• D. 10 mg

Answer: (B)

Delivering morphine directly into the cerebrospinal fluid makes it far more potent at producing spinal analgesia than giving it via the epidural space. The drug is placed right where the spinal cord’s opioid receptors sit, so a much smaller dose can achieve the same level of pain relief. Therefore, a dose around 1 mg intrathecally is typically enough to match the analgesia you'd get from about 10 mg given epidurally. Choosing a much smaller amount, like 0.1 mg, would usually be inadequate to reach analgesia comparable to 10 mg epidural. A much larger intrathecal dose, such as 5 mg or 10 mg, would increase the risk of adverse effects—especially delayed respiratory depression—without providing proportional benefit.

Delivering morphine directly into the cerebrospinal fluid makes it far more potent at producing spinal analgesia than giving it via the epidural space. The drug is placed right where the spinal cord’s opioid receptors sit, so a much smaller dose can achieve the same level of pain relief. Therefore, a dose around 1 mg intrathecally is typically enough to match the analgesia you'd get from about 10 mg given epidurally.

Choosing a much smaller amount, like 0.1 mg, would usually be inadequate to reach analgesia comparable to 10 mg epidural. A much larger intrathecal dose, such as 5 mg or 10 mg, would increase the risk of adverse effects—especially delayed respiratory depression—without providing proportional benefit.