Sunken_Civ has already pointed out the herbal smoke inhalation method..
This was used with either hemp (marijuana ! ) or with opium.. Both of these drugs could also be injested if the patient was conscious..
A couple of others I might mention would be the "black lotus" ( of "The Odyssey" ) and Cocaine or a close relative.. ( something very closely resembling cocaine was found in mummies in Egypt.. It is thought that it might have come from a plant relative of the Coca plant, but that it is now extinct or no longer known for it's properties..)
Cocaine can be used as a "local" anasthetic..
I would also guess there were other plants and herbs in use at the time, used in tincture form, tea, oils, salves, pastes, or other forms, full strength, diluted to desired strength, or mixed with other herbal drugs..
Another interesting possibility is Fly Agaric, thought to be the fabled "Soma" of Indian legend...
It might have been able to create an euphoric state in which the patient experienced the pain in other forms of experience... ( Fly Agaric is a strong hallucinagenic )
Cocaine or a close relative.. ( something very closely resembling cocaine was found in mummies in Egypt.. It is thought that it might have come from a plant relative of the Coca plant, but that it is now extinct or no longer known for it's properties..)The plant found in the mummies was cocaine, which means the Egyptians had a source. I figure it was that guy in "Blow".