A jab or pill? That is the tuberculosis question

The News

  • Recently South Africa became the first country to replace injectable drugs with the new oral medicine bedaquiline (BDQ) in its standard regimen for treatment of rifampicin-resistant tuberculosis (TB).

 

New summary

Drug Resistant TB

 

 

Multi-Drug Resistant (MDR) TB

  • A patient of MDR-TB stops reacting to the two strongest first-line anti-TB drugs, rifampicin and isoniazid.
  • Second-line treatment for MDR-TB includes daily intra-muscular injections for a minimum 9 months.
  • The three commonly-used injectables, kanamycin, capreomycin and amikacin, have severe side effects, including kidney ailments, hearing disability, and general toxicity.
  • Issues from usage of second line drugs
    • A study found that injectable treatment leads to hearing loss and toxicity in the ear.
    • They are toxic and painful, but unavoidable because there were no options.

 

Extensively drug resistant (XDR) TB

  • A patient who is resistant to isoniazid and rifampicin as well as to fluoroquinolones (levofloxacin or moxifloxacin), and to at least one of the three injectable second-line drugs is said to be suffering from extensively drug resistant (XDR) TB.

 

South Africa’s decision

  • In 2011, South Africa expanded the use of GeneXpert machines to diagnose a large number of MDR-TB patients and in 2013, the country’s Medicine Control Council approved use of bedaquiline (BDQ), a new magic drug for patients who are resistant to most standard drugs.
  • In its estimate for 2016 the World Health Organisation (WHO) put the incidence of TB in South Africa at 438,000.
  • Recently South Africa stopped injectables for all rifampicin-resistant patients and introduced bedaquiline, noting the severe toxic effects of injectables, which often led to treatment dropouts.
  • Apart from South Africa, there are no randomised clinical trial results on bedaquiline. Existing studies have shown bedaquiline may have cardiotoxicity.

 

The WHO’s recommendation

  • For drug-resistant TB, it recommends use of injectables.
  • Its guidelines on bedaquiline (BDQ) recommend use for pre-XDR or XDR patients under certain conditions.
  • WHO will have a Guideline Development Group meeting to further discuss the new drugs bedaquiline and delamanid, as well as injectables.

 

Situation in India

  • India carries the world’s biggest TB burden; incidence in 2016 was estimated at 2.79 million, or a quarter of all cases worldwide. WHO’s 2018 Global Tuberculosis Report estimates India’s MDR-TB burden at 147,000.
  • India is part of the global STREAM clinical trial to compare the effects of oral bedaquiline medication as opposed to a shorter regimen with injectable drugs.
  • Bedaquiline was rolled out in 2016 in a phase-wise control trial.

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