Information about a prescribed drug's side effects is usually in an insert of the drug's packaging. Much of the information is not easily understood to an average patient. (OK, I'm a bit "above average" b/c I read about a lot of meds and I ask my doctor friends some questions.)
We know that there is a general requirement to act morally and for a doctor to promote the health and healing of his patients to the best of his ability. By prescribing the meds in the first place, the doctor has probably accomplished this. He has assumed that all patients would also be self-responsible by reading the insert and / or asking the pharmacist about side-effects.
When a doctor prescribes a medication, is he halachically required to tell you about the drug's side effects before you use the drug? Or, can he assume that you will read and understand what's in the insert?
Your answer can account for the doctor's possible halachic liability for damages for not informing you, if this is one of other possible reasons that require him to tell you.
You need not assume that the patient is critically ill and / or close to death. (Those conditions may affect your answer, BTW.)
Even if we assume a general rule that patients have the responsibility to read the insert, much of what is in a typical insert is too technical, and patients may not understand some things that may be critical to them. Some things may have been omitted. For example, I have not seen a warning on statins that one should avoid eating grapefruit products, excessively. Is a doctor responsible for warning the patient of such things, or should he assume that a pharmacist would do this? (Some do, some don't)