Now there are several types, certain groups that affect the pathogenic organisms (except for broad-spectrum drugs). To determine the purpose of the drug, the doctor must accurately determine the type of infectious disease, pathogen and sensitivity to the selected active substance.
At appointment all is considered: age, weight of the patient, allergic reactions, severity of the disease. It is impossible to reduce the dose and interrupt treatment if the condition improves. This attitude to therapy can lead to further deterioration of the condition, loss of therapeutic effect, and the adaptation of bacteria to the antibiotic.
If it is not possible to accurately determine the type and type of pathogen, then broad-spectrum drugs are used that affect a number of pathogenic microbes.