Can he use medication which may cause his death to reduce pain?

Praise be to Allah.

We ask Allaah to grant you healing and good health. 

It is not permissible for the Muslim whom Allaah is testing with sickness to take something that will definitely or will most likely harm him. He is commanded to protect his body and it is not permissible for him to neglect the blessing of the physical faculties that Allaah has bestowed upon him. How can he neglect himself? 

One of the basic principles of Islamic sharee’ah is: “A harmful thing cannot be removed by something like it (i.e., something else that is also harmful).” Based on this, it is haraam to use as medicine something that will cause greater harm than the disease itself. 

See: Ahkaam al-Jaraahah al-Tibbiyyah, p. 124, by Shaykh Dr. Muhammad ibn Muhammad al-Mukhtaar al-Shanqeeti. 

Patience in putting up with pain and seeking the reward of Allaah are things that will benefit the Muslim in the Hereafter and increase his reward.  

It was narrated from Abu Sa’eed al-Khudri and Abu Hurayrah that the Prophet (peace and blessings of Allaah be upon him) said: “No tiredness, exhaustion, worry, grief, distress or harm befalls a believer in this world, not even a thorn that pricks him, but Allaah expiates some of his sins thereby.” Narrated by al-Bukhaari, 5318 and Muslim, 2573.  

Read the story of this great women and how she was afflicted by sickness – with all its pain – but she chose to bear it with patience in return for the great reward, which is admittance to Paradise. 

It was narrated that ‘Ata’ ibn Abi Rabaah said: Ibn ‘Abbaas said to me: Shall I not show you a woman who is one of the people of Paradise? He said: Yes. He said: This black woman came to the Prophet (peace and blessings of Allaah be upon him) and said: “I suffer from epilepsy and I become uncovered. Pray to Allaah for me.” He said: “If you wish, you can be patient and Paradise will be yours, or if you wish I will pray to Allaah to heal you.” She said, “I will be patient.” Then she said: “But I become uncovered. Pray to Allaah that I will not become uncovered.” So he prayed for her.

Narrated by al-Bukhaari, 5652; Muslim, 2576.  

Some doctors have stated that taking tranquillizers may cause a great deal of harm and lead to serious complications. 

Some specialists have said that it is possible to reduce pain through a nutritional program and an exercise regime, and other methods… You should consult more than one doctor; perhaps with another specialist you will find an answer that the one who told you to take that dangerous medication does not know about. 

But first and foremost, you have to be patient and accept the decree of Allaah; make a lot of du’aa’ and ask Allaah for good health, for Allaah says (interpretation of the meaning): 

“Who responds to the distressed one, when he calls on Him, and Who removes the evil”

[al-Naml 27:62]

We ask Allaah to take away your pain, and to decree reward for you, and to grant you wellbeing in your spiritual and worldly affairs, and to protect you and take care of you. 

And Allaah is the Source of strength.