I doubt that the truth could ever be a hazard if the person was rational. Besides, what about the refusal of treatment right? Lying breaches that as it makes them unable to rationaly make that decision. That right is the most importsant factor in this debate. And we should not cater to irrationality, even to save the life of the irrational.
As I said already, what about both? There is absolutely no reason why it is not possible to do both.
I think it is always wrong to lie to a patient because it breaches the right to refusal of treatment and because there is always a superior alternative.
Thats the thing, not everyone is ever going to be rationa all the time especially when they are seriously injured or ill. There is a good case for the doctor choosing to lie to the patient if he beleives the alternative is the patients most likely death. I think we can all see which is the best alternative and why this is so.
Lying to prevent a treatment right as you put it, probably woudlnt be justified. But let me try to give an example where lying to him in another case might be:
The patient has some disease, lets call it Illness A. Illness A is treatable by one known method, however the treatment contains a chemical the patient is against taking for some stupid reason (even to the point of death), and the doctor is convinced he will not be able to talk the patient out of his irrational beleif Now the doctor has the choice of allowing the patients paranoia, condemning himself to death , or lyhing to him and saying it deosnt contain the substance if the patient asks and having the patient at least be alive.
Such cases seem far fetched, but I have heard of such happening
Now a case that might apply to a more rational person. This time the treatment is considered based on the results of faulty experiments. The patient has accepted this data, not knowing the so called proof is wrong, its not a matter of irrationality, to his best judgement and knowledge, the experiments are correct. so he beleives and without being irrational that it is indicated the drugs are dangerous and will cause a worth death most likely than the illness.
Now the doctor however has objective proof that the experiments are wrong, it doesnt cause any significant harm, and should save the patients life. Now he doesnt have time to convince the patient that he is right, the proof is long and complicated, and he doesnt expect the patient will beleive his mere claims, as the patient beleives that he has proof that the treatment will kill him, and he deosnt want to die a worse death. So the doctor can lie, and say the treatment is something else, and save the patient, or he can let the patient die…he hasnt time to honestly get the patient to take the treatment knowing what is …even though the guy is rational and acting to thie best of what he beleives to be true.
Why is there ALWAYS an superior alternative?
Sometimes it is a matter of letting a patients irratioanl decisions kill them versus lying…I think the first is much worse than the latter. And you cannot say this never happens. And there are other cases involving even more rational people. So your “always” claim is false.