Chemoprophylaxis refers to the administration of a medication for the purpose of preventing disease. Antibiotics, for example, may be administered to patients with disorders of immune system function to prevent infection (particularly opportunistic infection). Antibiotics may also be administered to healthy individuals to limit the spread of an epidemic, or to patients who have repeated infections (such as urinary tract infections) to prevent recurrence. Oral medication A medication is a licenced drug taken to cure or reduce symptoms of an illness or medical condition. ... Contagious redirects here. ... An antibiotic is a drug that kills or slows the growth of bacteria. ... The Immune System (also known as the Immunlological System) is made up of all the mechanisms through which a multicellular organism defends itself from internal invaders such as bacteria, virus or parasites. ... An infection is the detrimental colonization of a host organism by a foreign species. ... Opportunistic infections are infections caused by organisms and usually do not cause disease in a person with a healthy immune system, but can affect people with a poorly functioning or suppressed immune system. ... In epidemiology, an epidemic (from Greek epi- upon + demos people) is a disease that appears as new cases in a given human population, during a given period, at a rate that substantially exceeds what is expected, based on recent experience (the number of new cases in the population during a... A urinary tract infection (UTI) is an infection of the urinary tract. ...

In some cases, chemoprophylaxis is initiated to prevent the spread of an existing disease in an individual to a new organ system, as when intrathecal chemotherapy is administered in patients with malignancy to prevent brain metastasis. Intrathecal: Delivered into the spinal canal (intrathecal space surrounding the spinal cord), as in a spinal anaesthesia. ... Chemotherapy is the use of chemical substances to treat disease. ... When normal cells are damaged or old they undergo apoptosis; cancer cells, however, avoid apoptosis. ... Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Metastasis (Greek: change of the state) is the spread of cancer from its primary site to other places in the body. ...

A related term is primary prevention, in which measures are undertaken to prevent the onset of disease in individuals who are susceptible (as when patients receive aspirin or statins to delay the development of coronary artery disease). In medicine, prevention is any activity by which an individual avoids the development of a disease or condition (primary prevention), diagnoses a disease in an early stage or prevents its reoccurance (secondary prevention), or avoids a diseases worsening and restores oneself to an optimal level of functioning (tertiary prevention). ... Aspirin or acetylsalicylic acid (acetosal) is a drug in the family of salicylates, often used as an analgesic (against minor pains and aches), antipyretic (against fever), and anti-inflammatory. ... Lovastatin, the first statin to be marketed The statins (or HMG-CoA reductase inhibitors) form a class of hypolipidemic agents, used as pharmaceuticals to lower cholesterol levels in people at risk for cardiovascular disease because of hypercholesterolemia. ... Coronary heart disease (CHD), also called coronary artery disease (CAD) and atherosclerotic heart disease, is the end result of the accumulation of atheromatous plaques within the walls of the arteries that supply the myocardium (the muscle of the heart). ...

The use of chemoprophylaxis is limited primarily by two factors:

• All medications have the potential to cause side 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 the incidence of the target disease is low. Many forms of chemoprophylaxis are therefore not cost-effective.

See also prophylaxis. An adverse drug reaction (abbreviated ADR) is a term to describe the unwanted, negative consequences sometimes associated with the use of medications. ... In optics one considers angles of incidence. ... Cost-effectiveness In economics, comparison of the relative expenditure (costs) and outcomes (effects) associated with two or more courses of action. ... Prophylaxis refers to any medical or public health procedure whose purpose is to prevent, rather than treat or cure, disease. ...