Understanding Morphine & Comfort Meds in End-of-Life Care

A large number of families arrive at the end of a cancer illness believing that morphine is what finally kills the patient. Some hold doses back. Some give half of what is prescribed. Some refuse to start it until the pain is severe, on the theory that it should be saved. The consequence is not neutral. It is hours or days of pain, breathlessness and agitation that had a treatment sitting on the kitchen counter.

Studies of opioid use in hospice and palliative care have repeatedly examined whether the dose a dying patient receives predicts how long they live. They found no such relationship. Work by Thorns and Sykes, by Bercovitch and colleagues on high-dose morphine in hospice, and by Morita and colleagues on high-dose opioids and sedatives in terminally ill cancer patients all point the same way: neither the absolute dose nor the rate at which it was increased was associated with shorter survival. NCI's patient summary states it without qualification, saying that studies have shown no link between opioid use and early death.

Opioids can suppress breathing. That fact is real, and it is where the fear comes from. It applies to a large dose given suddenly to someone who has never had one. It does not describe how these drugs are used at the end of life, where the dose is started low and raised in steps, each step checked against the symptom. Tolerance to sedation and to slowed breathing develops faster than tolerance to pain relief. Pain and breathlessness themselves stimulate breathing. The result is that a dose which would be dangerous to an opioid-naive person is unremarkable for someone who reached it gradually. The known cautions are rapid escalation in someone not yet exposed, and combining opioids with benzodiazepines without care, which is precisely why teams titrate rather than guess.

Low-dose opioids reduce the sensation of breathlessness, and this is one of their main uses in the last days. Families sometimes see morphine given to someone with no obvious pain and conclude that it must be for something else. It is for air hunger, and it works.

Doses are increased when someone is deteriorating. Deterioration is followed by death. That sequence puts a dose close to the moment of death for nearly everyone who dies with symptoms controlled, and it is easy to read as cause. The other changes in the same window, irregular breathing, mottled skin, unresponsiveness, are the illness advancing on its own timetable.

People taking regular opioids become physically dependent, meaning the drug cannot be stopped abruptly. That is not addiction, which is compulsive use despite harm. A person in the last weeks of a cancer illness is not going to develop a drug problem, and withholding relief to prevent one has no rationale.

The framework clinicians work within is that a medicine given with the intent of relieving suffering, at a dose proportionate to the symptom, is appropriate even if drowsiness is a foreseeable effect. The intention and the dose are the two things that distinguish symptom control from anything else, and both are documented in the notes.

Write down every dose and the time. Note what the symptom was before and after. Ask for a written plan covering the regular dose, the breakthrough dose, the maximum frequency, and what to do if a dose does not work within half an hour. Do not skip a scheduled dose because the person looks settled, since the settled state is what the dose is producing. If you are frightened of the medicine, say that to the nurse directly rather than quietly giving less.

• NCI PDQ, Last Days of Life (patient version): opioids and pain control
• NCI PDQ, Last Days of Life (health professional version): opioid dose and survival evidence
• Last Days of Life (PDQ) full text, NCBI Bookshelf