1,237.The Obligation to Heal

192:4 It is a mitzvah for a qualified doctor to heal people; this falls in the category of saving life. If he refrains from doing this, then it is considered shedding blood. This applies even if a sick person has another doctor because the patient may not necessarily merit to be healed by just anyone and maybe it was ordained that this doctor should be the one to cure him. However, one may not practice medicine unless he is qualified to do so and there is no better doctor available. If he does practice medicine when he shouldn't, he is committing bloodshed.

192:5 If a sick person is not in danger and he can be cured using something permitted - even though he must wait a little while to get it - then is not allowed to treat him using something prohibited. If he specifically requires something prohibited, if it must be eaten in the normal way, then he may not do so. This is true even for something that is only prohibited by Rabbinic law because the patient isn't in danger. However, if he can eat it without having benefit, such as by mixing it with something bitter, then it is permitted even with something that is prohibited for benefit by Torah law with the exception of kilay hakrem (mixed seeds of a vineyard) and meat-and-milk combinations, as these are prohibited even in a way that doesn't give one pleasure so long as the patient isn't in danger. As far as reciting blessings on things one eats or drinks for medicinal purposes, see 50:8 and 61:4 For the case of a child who needs to eat chometz on Pesach, see 117:12.