An
ethambutol resistance-associated M306V mutation in embB in 1 isolate was phenotypically undetected, probably reflecting known poor phenotypic reproducibility for this mutation (10).
Each patient received a daily total dose of rifampicin (600 mg), isoniazid (300 mg) pyrazinamide (1600 mg) and
ethambutol (1100 mg) for two months (intensive phase), followed by rifampicin (600 mg) plus isoniazid (300 mg) for four months (continuation phase).
Four first line anti TB drugs including rifampicin, isoniazid, streptomycin and
ethambutol were tested.
[20,21] One of the principal theories for ocular toxicity has been the zinc-chelating effect of
ethambutol and its metabolite inside the human mitochondria.
Furthermore,
ethambutol is not given in obtunded patients and in children as these are unable to report the possible visual complications inherently associated with TBM per se or
ethambutol use.
In Victoria, the Department of Health and Human Services contemporaneously recommended the use of fluoroquinolones in place of
ethambutol "in patients with renal failure, significant preexisting ocular disease or where ocular toxicity cannot be monitored" and as part of the treatment of MDR-TB.
She was resumed on the same regimen of Azithromycin,
Ethambutol, and Rifampicin.
kansasii infections had included INH, rifampin, and
ethambutol [10, 11].
This resident began treatment with a 6-month course of RIPE;
ethambutol was discontinued after drug sensitivities were confirmed.
Its mechanism of action is to bind with 16S ribosomal ribonucleic acid (rRNA) and inhibit translation initiation.3 Streptomycin resistance develops due to mutations in rpsL and rrS genes which are involved in the synthesis of ribosomal proteins.4
Ethambutol (EMB) targets the cell wall of M.
Despite the possible drug interactions and side effects of rifamycins, a 3-drug regimen containing clarithromycin,
ethambutol and rifabutin has been associated with fewer relapses and better survival compared to 2-drug regimens containing clarithromycin and
ethambutol or clarithromycin and rifabutin.
To enlarge the capacity for the detection of drug resistance, the WHO recommends the use of a line-probe assay, the GenoType MTBDR plus assay (Hain Lifescience GmbH, Nehren, Germany), which can identify the Mycobacterium tuberculosis (MTB) complex as well as resistance to rifampicin (RFP) and isoniazid (INH) drugs.[sup][7] The assay detects mutations in the rpoB gene for RFP resistance, katG gene for INH resistance, and inhA regulatory region gene for low-level INH resistance.[sup][8] Subsequently, a new DNA strip assay, GenoType MTBDR sl version 1.0 (Hain Lifescience GmbH, Nehren, Germany), was developed to detect resistance to
ethambutol (EMB), fluoroquinolones, and injectable aminoglycosides/cyclic peptides allowing diagnosis of XDR-TB among MDR-TB patients.