IS THE AGE OF ANTIBIOTICS OVER? Which drugsGlobal Priority Pathogens? Key to tackling the problem of antibiotic resistance is aligning research and development priorities with clinical needs. The 2017 WHO Global Priority List of Antibiotic Resistant Bacteria highlights where research, discovery and development efforts for new antibiotics should focus11. Firstly, Mycobacterium tuberculosis (TBff is the biggest global killer in the single infectious pathogen category causing an estimated 1.3 millions deaths in 201712. Additionally, multi- drug resistant (MDRff-TB is a major killer in the antimicrobial resistance category causing an estimated 251,100 deaths in 201712. MDR-TB is resistant to isoniazid and rifampicin, the most powerful anti-TB medicines. Extensively drug-resistant tuberculosis (XDR-TB) is defined as MDR-TB plus resistance to fluoroquinolones and injectable second-line anti-TB medicines. The main MDR-TB burden is located in India, China and the Russian Federation as shown in Figure 1. Treating MDR-TB is very difficult and generally more complex than the other pathogens listed below due to of several factors. Firstly, a combination of between 4 - 7 drugs are required for treatment because they are not as effective as first line treatments but there are only a limited number of second line drugs available. Secondly, many of these second-line drugs are toxic causing patients to have numerous and severe side effects such as vomiting, allergic reactions, seizures, kidney and liver failure. Thirdly, these adverse reactions must be managed appropriately meaning that extra resources are needed to treat these
complications and often these treatments are discontinued for long periods before being restarted prolonging the overall treatment period to between 9 - 20 months. Fourthly, treatments are very expensive because of these factors. Finally, sometimes these treatments cause permanent disabilities such as deafness and chronic neuropathy, depression and suicidal tendencies causing patients undergoing treatment devastating economic hardship. Due to these problems the success rate in treating patients globally is only 57%12. 00 Russian Federation China 0 Number of incident cases . 1000 10 000 India 0 0 0 0 0 O 0 0 0 100 000 150 000 0 5 Figure 1ffi Estimated incidence of MDR/RR-TB in 2017, for countries with at least 1000 incident cases12 The main MDR TB burden is located in India, China and the Russian Federation as shown in- Figure 1. Treating MDR-TB is very difficult and generally more complex than the other pathogens listed below because of several factors. Firstly, a combination of between 4 - 7 drugs are required for treatment because they are not as effective as first line treatments but
there are only a limited number of second line drugs available. Secondly, many of these second line drugs are toxic causing patients to have numerous and severe side effects such as vomiting, allergic reactions, seizures, kidney and liver failure. Thirdly, these adverse reactions- must be managed appropriately meaning that extra resources are needed to treat these complications and often these treatments are discontinued for long periods before being- restarted prolonging the overall treatment period to between 9 - 20 months. Fourthly, treatments are