What is the ruling on giving a father suffering from lung cancer the narcotic pills "Pallium" to alleviate his severe pain in the final stage of the disease?

There is no harm in taking pills if there is no alternative, because necessities permit the prohibited. Allah the Almighty said: (And He has detailed for you what He has forbidden you, unless you are compelled to it). And Allah the Almighty said: (But whoever is compelled, neither desiring [it] nor transgressing, there is no sin upon him). And Allah the Almighty said: (So fear Allah as much as you are able).