Combination therapy

Combination therapy or polytherapy is the use of more than one medication or other therapy. In contrast, monotherapy is any therapy which is taken by itself.

Most often, these terms refer to the simultaneous administration of two or more medications to treat a single disease. However, the expression is also used when other types of therapy are used at the same time, such as the combination of medications and talk therapy to treat depression.

Combination therapy may be achieved by giving separate drugs, or, where available, by giving combination drugs, which are dosage forms that contain more than one active ingredient.

Polypharmacy is the use of multiple medications to treat multiple, separate diseases.

Uses for combination therapy
Conditions treated with combination therapy include tuberculosis, leprosy, cancer, malaria, and HIV/AIDS. One major benefit of combination therapies is that they reduce development of drug resistance, since a pathogen or tumor is less likely to have resistance to multiple drugs simultaneously. Artemisinin-based monotherapies for malaria are explicitly discouraged to avoid the problem of developing resistance to the newer treatment.

Combination therapy may seem costlier than monotherapy in the short term, but when used appropriately, it causes significant savings: lower treatment failure rate, lower case-fatality ratios, slower development of resistance and consequently, less money needed for the development of new drugs.

Uses for monotherapy
Monotherapy can be applied to any therapeutic approach, but it is most commonly used to describe the use of a single medication. Normally, monotherapy is selected because a single medication is adequate to treat the medical condition. However, monotherapies may also be used because of unwanted side effects or dangerous drug interactions.