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 it is used appropriately, it causes significant savings: lower treatment failure rate, lower case-fatality ratios, fewer side-effects than monotherapy, slower development of resistance, and thus less money needed for the development of new drugs.
In oncology Combination therapy has gained momentum in oncology in recent years, with various studies demonstrating higher response rates with combinations of drugs compared to monotherapies, and the FDA recently approving therapeutic combination regimens that demonstrated superior safety and efficacy to monotherapies. In a recent study about solid cancers,
Martin Nowak,
Bert Vogelstein, and colleagues showed that in most clinical cases, combination therapies are needed to avoid the evolution of resistance to targeted drugs. Furthermore, they find that the simultaneous administration of multiple targeted drugs minimizes the chance of relapse when no single mutation confers cross-resistance to both drugs. Recent
precision medicine approaches have focused on targeting multiple biomarkers found in individual tumors by using combinations of drugs. However, with 300 FDA-approved cancer drugs on the market, there almost 45,000 possible two-drug combinations and almost 4.5 million three-drug combinations for to choose from. That level of complexity is one of the primary impediments to the growth of combination therapy in oncology.
Bacterial infections Combination therapy with two or more antibiotics are often used in an effort to treat multi-drug resistant Gram-negative bacteria. However, it may also increase treatment costs and the risk of drug toxicity or other adverse effects. ==Contrast to monotherapy==