The expected course of late stage lung/liver cancer entails a lot of sleeping. Most likely he is sleeping because the liver is not working properly. It is very important to stay on top of the pain. Sometimes in the final days, it comes down to a choice of having him more alert but in pain or less alert and comfortable. But there are some things that you can try that will not affect his “alertness.” And that may help with the pain.
The Vicodin may have worked better(for awhile) than the Morphine does now because it contains both an opioid(hydrocodone) plus Tylenol, where the Morphine is only an opioid. Both Hydrocodone and Morphine are terrific pain medications but they work well for certain kinds of pain and not for others. The average cancer patient has up to three different kinds of pain and not all respond to opioids. To get the best pain management, it is considered good practice to give some sort of non-opioid analgesic with the Opioid(Morphine). Non-opioid analgesics are Tylenol, Advil, and Aspirin etc. You would not want to use Advil or aspirin as they could cause bleeding. Most hospices use Tylenol.
Therefore, it you add Tylenol to his Morphine dosage, he may get more comfortable without compromising his mental status. One dose every 6 hours is the usual dose and you can get Tylenol both in Liquid and suppositories.(Some of the hospices have a comfort kit with medications in the home that contains both the pill and suppository). If you try this and he is still in pain, I would follow the hospice’s suggestions to increase his Morphine until he is comfortable. It is very important to get his pain under control and to keep it under control as much as possible. Tell your sister, that there is now research that shows that patients who receive opioid pain medication actually live longer than those who do not. Severe pain shortens life. There is no reason to withhold pain medication. The risk of addiction is less than .1%. While it is true that the Morphine dosage needs to be continually increased because all patients will develop tolerance to their current dose, the medication can be increased and there is no limit to the amount he can receive. Poorly managed pain can lead to agitation and delirium which is much more difficult to manage in a dying patient. The hospice changed from Vicodin to Morphine because Morphine has no ceiling and can be given in increasing doses, while Vicodin needs to be limited because of the Tylenol. Each Vicodin contains 750 mg. of Tylenol and so you cannot take more than 5 tablets in 24 hours or you will exceed the 4000 mg. a day limit and someone can become toxic from the Tylenol. If he takes Tylenol separately four times at 650 mg each he will be taking 2600 mg a day which is far less that the 4000 mg limit. Tylenol helps some types of pain that are not helped by Morphine. The two medications together work better.
I hope you are able to make you Dad more comfortable. Remember that you can call the hospice nurses 24 hours per day if you need them to make a consulting visit. It is helpful to use numbers with your father to accurately communicate the amount of pain he is having. “10” is worst pain and “0” is no pain.