What is the primary adverse effect to monitor for when administering hydromorphone for severe pain?

Choice A reason: Hepatotoxicity is not a primary concern with hydromorphone. While liver function should be considered in all drug metabolism, hydromorphone is not known for causing liver damage. Choice B reason: Renal impairment may affect drug clearance, but it is not the most critical adverse effect. Dose adjustments may be needed, but renal toxicity is not a hallmark of hydromorphone. Choice C reason: Respiratory depression is the most serious and potentially life-threatening adverse effect of opioid analgesics like hydromorphone. It results from suppression of the brainstem respiratory centers and requires close monitoring, especially in opioid-naïve patients. Choice D reason: Gastrointestinal bleeding is not associated with hydromorphone. This adverse effect is more common with NSAIDs due to their impact on gastric mucosa and platelet function.