Treating mono and poly-drug resistant TB

Clinical description

When a decision has been made to modify, the most effective regimen should be chosen from the start to maximize the likelihood of cure; effective drugs should not be withheld for later use.

The recommendations for treating patients with mono- and poly-resistant strains are outlined in table below:

16 Medicines in Groups A and C are shown by decreasing order of usual preference for use (subject to other considerations; see text)

17 Refer to the text for the conditions under which streptomycin may substitute other injectable agents. Resistance to streptomycin alone does not qualify for the definition of extensively drug-resistant TB (XDR-TB) (26)

18 Carbapenems and clavulanate are meant to be used together; clavulanate is only available in formulations combined with amoxicillin National Tuberculosis Control Programme 77 Table 10.4-2: Suggested regimens for mono- and poly-drug resistance SUGGESTED DRUG RESISTANCE PATTERN COMMENTS REGIMEN RIF mono- or poly-drug DR-TB regimen The patient should be started on either a shorter or resistance individualized DR-TB regimen depending on eligibility criteria INH poly-drug resistance DR-TB regimen Treat as DR-TB. Caution should be taken when susceptible to RIF interpreting these DST results, as many patients with DST results suggesting poly-drug resistance actually have MDR-TB. Determine the patient’s treatment history. If (e.g. INH + EMB and/or S any doubt, consult with the clinical expert committee.

resistance)

INH mono-resistance Consult clinical Patient with no previous treatment of TB, no risk of team for regimen amplification of resistance, and no risk of unfavorable selection outcome: consider treatment with levofloxacin + REZ for 6 Note: should be diagnosed by full months (+/-INHHD).

phenotypic DST, if available, and not only by FL LPA Patient with history of previous TB treatment, risk of amplification of resistance, or risk of unfavorable outcome (extensive disease) treat with an individualized treatment regimen.

H = Isoniazid; R = Rifampicin; E = Ethambutol; Z = Pyrazinamide; S = Streptomycin Care should be taken to evaluate the medical history for possible amplification of resistance which may have developed but may not be apparent from the laboratory results. As such, treatment for mono and poly-drug resistant TB should never rely solely on DST results.

It is important to assess history of previous TB treatment, contact history, risk of amplification of resistance, extension of the disease and patient condition.

Though there is clear guidance to treat all Rif mono or polyresistant patients with MDR treatment regimens, by the time of developing this guideline, there is no updated international recommendation on the treatment of H mono and poly=resistance.

NOTE: FL LPA gives only results for Rifampicin and Isoniazid.

If Rif sensitive and H resistant, H can be either Mono or Poly H resistant The diagnose of H poly resistance should be done by first line phenotypic DST 78 National Tuberculosis Control Programme Type of resistance and suggested drug to be used Table 10.4-3: Type of resistance and suggested drug to be used Type of resistance Drugs/regimen used Sensitive TB H, R, E, Z R - resistance H, R - resistance Short or individualized regimen according to the eligibility criteria H, R, S To reconsider Pre XDR and XDR regimens. Generally, the backbone is Bdq H, R, Km or Dlm, Cfz and linezolid.

To reconsider Pre XDR and XDR regimens. Generally, the backbone is Bdq H, R, Cm or Dlm, Cfz and linezolid.

To reconsider Pre XDR and XDR regimens. Generally, the backbone is Bdq H, R, FQ and / or Dlm, Cfz and linezolid.

To reconsider Pre XDR and XDR regimens. Generally, the backbone is Bdq H, R, Inj, FQ and / or Dlm, Cfz and linezolid.