Morphine has opioid agonist activity that can cause respiratory depression and death in overdose.

Morphine-6-glucuronide is the metabolite that can accumulate and cause CNS toxicity in renal failure.

Be aware of CNS depressants that may enhance the effect of morphine and other opioids. Some examples of CNS depressants include gabapentin, benzodiazepines, older antihistamine, skeletal muscle relaxants, and pregabalin.

Opioid withdrawal is a significant concern when patients have their morphine or another opioid abruptly stopped. Some signs of withdrawal include agitation, mood swings, anxiety, sweating, GI upset, pain, and insomnia.