Antibiotics lose effectiveness over time as bacteria mutate and become resistant to the drug’s effects. The rate of growth of antimicrobial resistance accelerated over the years as a result of the widespread and global use of antibiotics. The extensive use of antibiotics both inside and outside of medicine is playing a significant role in the emergence of resistant bacteria. Although there were low levels of preexisting antibiotic-resistant bacteria before the widespread use of antibiotics, evolutionary pressure from their use has played a role in the development of muiltidrug resistance varieties and the spread of resistance between bacterial species. In some countries, antibiotics are sold over the counter without a prescription, which also leads to the creation of resistant strains. In human medicine, the major problem of the emergence of resistant bacteria is due to misuse and overuse of antibiotics by doctors as well as patients. Other practices contributing towards resistance include the addition of antibiotics to livestock feed.
Antibiotic drug development by pharmaceutical companies is extremely challenging. There are exceptional drug discovery challenges, regulatory complications and commercial issues. Discovering new antibiotics is inherently difficult and finding novel agents that successfully target bacteria is scientifically challenging. There are regulatory complexities specific to antibiotics. For example, late stage clinical trials investigating antibiotics against resistant infections require an excess number of trial participants, as not all those enrolled with be infected with the resistant strain of bacteria being targeted. There is a low return on investment for antimicrobials compared to other medicines. This limits the feasibility of antibiotic development for the pharmaceutical manufacturers. New antibiotics are used sparingly – only when patients have failed to respond to existing therapies. This significantly limits the commercial return that is needed to encourage investment in antimicrobial research and development and to fund it into the future.
Drug-resistant organisms take an astonishing toll world wide. In the United States one of these organisms, Staphylococcus aureus (MRSA), kills more Americans every year than emphysema, HIV/AIDS, Parkinson’s disease and homicide combined. Almost 2 million Americans a year develop hospital-acquired infections (HAIs), resulting in 99,000 deaths. The vast majority of the mortalities are due to antibacterial (antibiotic)-resistant pathogens. Sepsis and pneumonia alone, two common HAIs, killed nearly 50,000 Americans and cost the US health care system more than $8 billion in 2006. A 2009 survey showed approximately half of the patients in more than 1,000 intensive care units in 75 countries suffered from an infection and the infected patients were twice as likely to die in the hospital as the uninfected patients. Three recent studies of the costs of infections caused by antibiotic-resistant pathogens versus antibiotic-susceptible pathogens show the annual cost to the US health care system of antibiotic-resistant infections to be $21 billion to $34 billion and more than 8 million additional hospital days. At least 25,000 patients in the European Union die from an infection caused by multidrug -resistant bacteria with estimated health care costs productivity losses of more than 1.5 billion Euros. READ MORE