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Source: actbistas.org
Updated WHO multidrug-drug-resistant tuberculosis (MDR-TB) treatment guidelines.
The latest drug resistance surveillance data show that 4.1% of new tuberculosis (TB) cases and 19% of previously treated cases in the world are either rifampicin-resistant or multidrug-resistant (RR/MDR-TB).
Globally, in 2016, there were 600,000 estimated new RR/MDR-TB cases, which caused 240,000 deaths. Most of those cases and deaths occurred in Asia. Around 6.2% of MDR-TB cases are also resistant to other drugs, i.e. extensively drug-resistant tuberculosis (XDR-TB).
Recently, at least 36 African and Asian countries have introduced shorter MDR-TB regimens, which have reached treatment success rates comparable to drug-susceptible TB under operational research conditions.
In June, 2017, it was reported that 89 countries had imported or had started using bedaquiline, and that 55 countries had been using delamanid. These two new medicines were conditionally approved by the most stringent regulatory authorities for the treatment of MDR-TB in recent years.
In August, 2018, WHO announced some modifications to the MDR-TB treatment guidelines.
Based on new available data, and with the collaboration of a great number of stakeholders, WHO has moved forward in rapidly reviewing evidence and communicating the key changes needed to improve MDR-TB patients’ chances of survival around the world.
The current political momentum urgently needs to be accelerated if the MDR-TB global crisis is to be contained. To prepare countries for the implementation of these changes, WHO has published a rapid communication to explain the new priority ranking of the available medicines for MDR-TB treatment.
The main goal of the WHO rapid communication is to encourage and prepare countries to implement the upcoming new consolidated, updated and more detailed policy guidelines on MDR-TB treatment. The MDR-TB treatment overview will undergo a radical transformation, for the better. WHO is also establishing a multi-stakeholder Task Force to coordinate support to national anti-TB programs in their rapid transition towards the key changes foreseen.
Following the key changes announced, a major improvement in treatment outcomes and quality of life of MDR-TB patients is expected.
The first important change is a new priority ranking of the available medicines for MDR-TB treatment, based on a careful balance between the expected benefits and harms. Nowadays, preferred treatment options include a fully oral regimen. Treatment success for MDR-TB is currently low in many countries. This could be increased by improving access to the highest-ranked medicines for all MDR-TB patients.
The longest MDR-TB regimens are divided into three categories: 1) Group A medicines (levofloxacin/moxifloxacin, bedaquiline and linezolid) are to be prioritized; 2) Group B medicines (clofazimine and cycloserine/terizidone); 3) Finally, when agents from Groups A and B cannot be used, Group C medicines could be included to complete the regimen: ethambutol, delamanid, pyrazinamide, imipenem-cilastatin, meropenem, amikacin (streptomycin), ethionamide/prothionamide, and PAS (p-aminosalicylic acid).
WHO no longer recommends kanamicin and capreomycin due to an increased risk of treatment failure and relapse when used in longer MDR-TB regimens.
In the new guidelines, WHO prioritizes oral medicines, such as bedaquiline, over injectable agents, which could cause pain and distress to patients, with serious adverse effects that often lead to the treatment being interrupted.
WHO has also based its ranking on results of drug-susceptibility testing (DST), reliability of existing DST methods, population drug resistance levels, history of previous use of medicines, drug tolerability and potential drug-drug interactions.
WHO has announced that the consolidated, updated and more detailed treatment policy guidelines on MDR-TB will be released later this year. On September 26, 2018, global leaders will gather in New York to hold the first United Nations General Assembly High-Level Meeting on Tuberculosis.
Source:WHO