A medication reaction is a response of an organism or a living tissue to an antigen. There are many types of medication reactions like allergic reaction, stress reaction, hypersensitivity reaction, antigen-antibody reaction, adverse reactions, etc. All of these reactions occur when a patient takes different medications. This reaction depends entirely upon the medication and the cause it was taken.

A destructive reaction to a drug or medical procedures is known as adverse reaction. The reaction can cause minor to major problems. An adverse reaction is mainly initiated due to the use of some stuff or medications. The effect of this reaction may be sudden or come in a slow process over long time. Most of these adverse reactions to medications are non-allergic. The clinical symptoms for aspirin medication reaction are like angioedema, aplastic anaemia, Reye’s syndrome, hepatotoxicity, agranulocytosis, DIC, GI ulceration, bleeding, bronchospasm, nephrotoxicity, etc. These are some of serious results and some very common symptoms are nausea, vomiting, abdominal pain, rashes, dizziness, hyperuricemia, ecchymosis, constipation, diarrhea, etc.

Depressive reaction is an emotional response given to outside conditions. This is a medication reaction and the problem is resolves only when the outside problems are solved. In psychotic depressive reaction, the patients with a very serious depression give proof of misapprehension of the truth and sometimes exhibit delusions or hallucinations.  These patients have the symptoms of depressed mood, suicidal wishes, self-accusations and hopelessness.

Antigen-antibody reaction is also a type of medication reaction, which occurs when an antigen unite with its corresponding antibody to generate an immune complex. An immunogen is a substance that encourages the immune system to form a corresponding antibody. Using a special procedure of washing and application of the negative staining method, agglutination of precipitation of protein and virus particles are found on the particle surfaces. These reactions are not noticed after the therapy with normal serum or heterologous antiserum.

A medication reaction of hypersensitivity occurs within short time of patient exposed to the challenging antigen since the antigen releases histamine, which in turn follows antigen-antibody reaction. This hypersensitivity causes muscle contraction and increases vascular permeability. There is a very long list of causes. The hypersensitivity reaction causes autism, hypersensitivity to sensory stimuli; chemical poisoning, cirrhosis of the lever, spinal cord injury, abdominal discomfort, abdominal distension, swelling, abnormal eye moments, abnormal gait in children, etc.

Allergic reaction is an unwanted and uncommon side effect of the medication reaction. An immune system protects our body from harmful agents like toxins or bacteria. When foreign substance enters our body, the immune system gets charged up. This foreign body is called the antigen. When this immune system over reacts to the non-toxic substance or allergen it becomes allergic reaction. Reaction to medications can happen from as mild as rashes to serious effects on body system. The medication reaction affects most part of the body including many organs but in all the cases skin is almost involved. It is very important to check immediately for the drug allergies since they can be life threatening. Usually death from these allergies is very rare. When a medication is taken for the first time, it does not show any allergies but medication reaction comes up when a patient takes the same medications for the next time.