Multi drug therapy- the new weapon against cancer

 We all know that multi-drug therapy is a key way to prevent the emergence of resistance in infectious diseases. It not only provides rapid cure but also stamps out those strains of the infective organism which would have easily survived the onslaught of a single drug. Like the infectious organisms, cancer cells are also rapidly dividing cells, the growth and spread of which can be stopped using chemotherapy. There is astonishing similarity between drug resistance seen in infectious diseases and cancer. Infectious organisms have learnt to evade killing by antimicrobials by developing multiple mechanisms. In recent times, the problem of resistance in infectious organisms has become rampant and we find ourselves in very difficult situation to combat the infectious organisms. Similarly, in cancers which were sensitive to single drug of chemotherapy has over a period of time become more and more resistant. To overcome this problem multiple drug therapy with multiple anti-cancer drugs acting at multiple levels have been developed which not only kills the cancer cells in a shorter period of time but also prevents the development of resistance. Use of multiple drugs also decreases the chances of adverse effects associated with use of high dose of a single drug in cancer chemotherapy The doses of the respective drugs can be reduced such that the toxicity profile is much better. Nowadays we have an armamentarium of drugs against cancer-cytotoxics, biologicals, monoclonal antibodies, hormonal therapy. These drugs acts by different mechanisms and are effective in remission of cancer which otherwise would not have been possible with a single drug. In a classical example of drug resistance associated  with PGP (P glycoprotein) or MDR (multi-drug resistance protein), the cancer chemotherapeutic agent is extruded out of the cancer cells by the PGP resulting in decreased efficacy of the agent. In such conditions multiple drugs enables the remission of cancer even when one of the drugs is extruded out from the site of its action.