Example scenario: Tuberculosis.
Two phases are involved in TB treatment. Each phase has a different combination of drugs and drug use. In the initial phase (also known as intensive or first-line), 4 drugs are recommended to be used daily over two months. The goal is to eliminate rapidly-growing bacteria and reduce the chance of developing resistance. It is crucial that patients adhere to the prescribed medications during this phase. If one medication is missed or taken incorrectly, it can result in decreased efficacy and possibly resistance. After completion of intensive phase culture results from sputum samples should be obtained to assess whether any drug needs changing based on sensitivity test results – this process may require additional rounds of testing if response is inadequate after initial tests were conducted; however, four drugs initially prescribed will remain as part of treatment course even if changes need to be made afterwards during continuation phase which follows intensive one after patient completes two month long course with all four medications.
Continuation phase usually lasts between 4 and 7 months, depending on the response to medical checkups (culture tests) prior to beginning second half of TB treatment. Patients will usually be given fewer medications once they reach the continuation stage. The main purpose of this stage is to maintain remission, not eliminate infection completely (which occurred during intensive phase). Continuation stage usually consists out three medications: Isoniazid and Rifampin which do not have significant side effects that would outweigh their benefit; third drug might either stay same as before or change depending on results from cultures prior to entering continuation stage – Ethambutol may stay same although in some cases PAS can also be added instead/with other two mentioned above.
Combination drug therapy is effective in fighting tuberculosis. It also reduces the chance of virus replication enough to develop resistance against certain medications. This makes future treatment more challenging due to decreased sensitivity toward active ingredients commonly found in TB medication like Isoniazid and Rifampin.