Chemoprevention orchemoprophylaxis refers to the administration of amedication for the purpose of preventingdisease orinfection.^[1][2]Antibiotics, for example, may be administered to patients with disorders ofimmune system function to prevent bacterialinfections (particularlyopportunistic infection).^[3] Antibiotics may also be administered to healthy individuals to limit the spread of anepidemic, or to patients who have repeated infections (such asurinary tract infections) to prevent recurrence. It may also refer to the administration of heparin to prevent deep venous thrombosis in hospitalized patients.

In some cases, chemoprophylaxis is initiated to prevent the spread of an existing infection in an individual to a new organ system, as whenintrathecalchemotherapy is administered in patients withmalignancy to prevent further infection.

The use of chemoprophylaxis is limited primarily by two factors: risk and financial costs.

• All medications have the potential to causeside effects. In general, chemoprophylaxis should be initiated only when the benefits of treatment outweigh the risks.
• The cost associated with chemoprophylaxis may be prohibitive, particularly when the cost of treatment is high or theincidence of the target disease is low. Many forms of chemoprophylaxis are therefore notcost-effective.

Using chemoprophylaxis as a treatment against early signs oftuberculosis has proven to be effective.^{[citation needed]} Infamilial adenomatous polyposis physicians observed polyps regression withNSAIDs for anti-inflammatory therapy.^{[citation needed]} Chemoprophylaxis is also used to treat several different varieties of meningococcal infections for close contact exposure toNeisseria meningitidis.^{[citation needed]}

TheWorld Health Organization recommends chemoprevention to prevent Malaria in the Sahel region of Sub-Saharan Africa through the use of the drugssulfadoxine/pyrimethamine andamodiaquine.^[4] This technique is called Seasonal Malaria Chemoprevention (SMC). The charity evaluatorGiveWell lists the Malaria Consortium's SMC program as one of its priority programs due to its high level of cost-effectiveness and ability to absorbe additional funding.^[5]

Chemoprevention in cancer, was first proposed byMichael Sporn, seeks to identify ‘agents to reverse, suppress or prevent the carcinogenic process,’ from premalignancy to invasive and ormetastatic cancer, by ‘using physiological mechanisms that do not kill healthy cells.^[6]Anand Reddi proposed a role for the antidiabetes drugmetformin as a chemoprevention agent forskin cancer.^[7]

• Prophylaxis, a more general term.
• Primary prevention, in which measures are undertaken to prevent the onset of disease in individuals who are susceptible (as when patients receiveaspirin orstatins to delay the development ofcoronary artery disease).

• Medical terminology
• Medical treatments
• Infection-control measures
• Chemotherapy

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