MDR-TB Treatment & Prevention
Has poly-resistant become MDR TB?
Dear all,
I would like your input on a complicated case from our TB clinic in Phnom Penh, Cambodia.
A 69-yr old man, HIV-negative, with no previous history of TB, was diagnosed with smear-pos PTB and started cat I treatment on May 25. He remained smear pos 2+ after two months, and for this reason RHEZ was continued for a third month. At that time his culture result confirmed MTB growth. DST (proportion method) was done as it is done on all positive cultures in our project. The result however was only available at month 3 (August 22). DST result: INH (high and low dose) resistant, strepto and ethambutol resistant; rifampicin, oflox and kanamicin sensitice. At that time the patient had also converted sputum smear to neg. He was changed to continuation phase with R and Z by one of our doctors without discussion. We reviewed the results in team today. The patient is still coughing intermittenly though productive. He feels much better and has gained 7 kg over the last three months. No more fever or night sweats.
So, at best our patient has received bitherapy for over 3 months, maybe monotherapy? We suggest to repeat culture and DST but in the mean time,
how should we continue his treatment?
Cambodia has a relative low prevalence of MDR TB: 1,4% among new cases and 10,5% among retreated persons.
- Should we consider him as potentially MDR TB and refer him for empirical treatment while awaiting repeat culture and DST (another 3 months since we do not have rapid molecular tests yet)? It is not sure whether he will accept this since he is clinically improving.
- Or should we put him on a continuation phase; if so, a combination of which drugs?
All suggestions would be welcome since the experience here is rather limited. Second line drugs are available in the country.
Kind regards,
Natalie Lorent
Md. Abdul Hamid Salim
Dear Natalie,
We have some experiences to manage such poly resistance cases in Bangladesh. In this specific case i would suggest the following:
- Since patient responded well clinically ( 7 KG weight gain, no fever etc) i would suggest to continue continuation phase but adding high dose of H with RZ. We have experience in Bangladesh that although H resistance but adding H increases the cure rate even for MDR TB cases.
I would suggest also not to add any second-line drug in the continuation phase this may simply end up as an XDR- because, if he is not cured with the ongoing treatment it is well possible that he is already an MDR. Adding single second-line drug to continuation phase may lead to create resistance to secondline drug.
It is better to wait for the culture and DST result-in casethe results shows that he is a MDR, i would suggest to put on full MDR regimen following country policy/WHO guidelines. If the culture and DST shows negative i would just continue the continuation phase and the full duration of treatment could better be extended upto 12 months.
Hope this can be helpful.
MA Hamid Salim
5:50 AM, 6 Sep 2011 | Permalink
Natalie Lorent
Dear Hamid Salim,
Thanks for suggestion. Just one clarification: would you anyhow recommend
high dose H even if DST tested at INH 0,2 µg/ml and 1,0 µg/ml were resistant?
Kind regards,
Natalie
6:12 AM, 6 Sep 2011 | Permalink
Jann-Yuan Wang
Besides continuing RMP and PZA, I will add high-dose INH for this patients for two reasons. First, using high-dose INH can probably achieve a serum level of more than 10 ug/L, which is 10 times above 1.0 ug/L. Second, given that greater than 1% growth in the drug-containing culture plate is defined as resistance, probably more than 90% of TB bacilli may still susceptible to INH. Therefore, I will still use high-dose INH, but will not count it as an effective drug.
1:09 PM, 6 Sep 2011 | Permalink
Natalie Lorent
Thanks for your suggestion. The patient was started on the proposed regimen
today.
Natalie
5:13 AM, 7 Sep 2011 | Permalink
Victor Lizarbe
Hello Natalie
In Peru we have high rates of drug resistance as is generally known, in situations like the case presented, we tend to be more aggressive.
As summarized by the DST crews is the third month of treatment, after the sampling of the DST (3° m) received R and Z for three months, which means that it has received a total of six months of treatment with: R Z.
Under this condition with resistanceto HSE, in addition to the clinical and bacteriological must evaluate the evolution of radialogic injury, if radiologic injury persists or evolution has not been adequate; it is better to design a treatment regimen that considers 03 new drugs to which has not been exposed, could be: kanamycin, levofloxacin,Ethionamid;R and Z add additional drugs.
Victor Lizarbe
Hospital Loayza
Lima Perú
11:55 AM, 7 Sep 2011 | Permalink