What information do you need to share with your doctor to avoid a possible bad reaction to medication?

You need to provide: 
-what other meds you're on
-parents medical history if possible
-allergies
-any surgical procedures you have ever had in your life
Hope this helps!

The information that you need to share with your doctor to avoid a possible bad reaction to medication is:

Allergies: It is possible that the patient is allergic to one or several components of the given medication, so, unlike curing a condition, he can create another.Recurring diseases in family members: Since medications that are very strong can affect some organs such as the stomach or pancreas, the doctor must know the common diseases in the patient's family in order to identify whether when consuming the medication is prone to affect another organ or system.Other medications taken: The medications may be incompatible with each other, so it is important that the doctor knows what medications are currently being taken and thus can prescribe a medication that is not incompatible with those already supplied.

Explanation:

When a person requires that they be prescribed medications to cure a disease they suffer from, it is very important that they consider providing all the possible information to the doctor, since this way the risks of consuming such a drug are reduced, in some occasions it must be mention even if you have wounds, since some medications can be irritating.

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