Standard regimens of ATT DRUGS and TREATMENT PROTOCOLS

1. STANDARD REGIMENS OF
ATT DRUGS

2. • The three major actions of anti-tuberculosis drugs are
1) Bactericidal action,defined by the ability to kill actively growing
bacilli rapidly
2) Sterilizing action,defined by the ability to kill the semi dormant
organisms
3) Prevention of emergence of drug resistance
Isoniazid is the most potent bactericidal drug,followed by rifampicin
Rifampicin and pyrazinamide are important for sterilizing the TB lesions
and preventing disease relapse

3. • Among the first line anti-tubercular drugs,isoniazid and rifampiicin are
most effective in preventing the emergence of drug resistance
• Streptomycin,ethambutol and para-amino salicylic acid are less so
• And thioacetazone and para-amino salicylic acid are the least
effective for the purpose

4. • Standardized treatment means that all patients in a defined group
receive the same treatment regimen. Standard regimens have the
following advantages over individu- alized prescription of drugs:
• Errors in prescription – and thus the risk of development of drug
resistance – are reduced;
• Estimating drug needs, purchasing, distribution and monitoring are
facilitated
• Staff training is facilitated and costs are reduced
• Maintaining a regular drug supply when patients move from one area to
another is made easier;
• Outcome evaluation is convenient and results are comparable.
WHY ARE STANDARD REGIMENS REQUIRED?

5. • All regimens have two phases:
•Initial intensive phase:
Designed to kill actively growing and semi dormant bacilli,,resulting in
shorter duration of infectiousness usually with rapid smear conversions
after 2-3 months of treatment
•Continuation phase:
Designed to eliminate most residual bacilli and decreased failures and
relapses

6. GROUP 1 GROUP 2 GROUP 3 GROUP 4 GROUP 5
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
Streptomycin
Kanamycin
Amikacin
Capreomycin
Viomycin
Ciprofloxacin
Ofloxacin
Levofloxacin
Moxifloxacin
Gatifloxacin
Ethionamide
Prothionamide
Cycloserine
Terizidone
PAS
Thioacetazone
Clofazimine
Amoxicillin/Clavulinat
e
Linezolid
Imipenem/Cilastin
Clarithromycin
High dose Isoniazid
CLASSIFICATION OF ATT DRUGS

8. Aims of Chemotherapy of TB are to:
• Cure the patients of TB by the shortest duration of drug
administration with minimum interference with their living
• To Prevent death from TB or late sequelae of disease
• To prevent relapse of TB
• To prevent emergence of drug resistance
• To reduce transmission of disease to people both within and outside
the community

10. Treatment of smear positive PTB
• Most regimens are given for a total duration of six months,this being currently the
shortest required
• Regimens that do not contain pyrzinamide initial intensive phase must be given for
longer than six months
• The current standard regimen prescribed by WHO and IUATLD(international Union
against tuberculosis and lung diseases) comprises of four drug regimen in initial
intensive phase and two drug in continuation phase(2HRZE/4HR or 2SHRZ/4HR)
• However for individual cases with extensive disease and slow bacteriological
conversion prolongation of pyrzinamide beyond two months is acceptable and
prolongation of treatment to 9months may aLos be considered
• Intermittent regimens with four months of daily doses with four drugs followed by
two drugs in continuation phase is shown to be highly effective in recent
studies(2SHRZ/4H*3 R*3

11. Treatment of smear negative pulmonary TB
• In many countries around 50 percent of patients have been found to be
having active pulmonary TB without immediate bacteriological
confirmation
• The WHO recommends in the latest guidelines the use of six month
treatment regimens consisting of daily isoniazid,rifampiicin,ethambutol
and pyrazinamide followed by daily or thrice-weekly isoniazid and
rifampiicin for another four months in the treatment of new cases of
smear negative PTB
• ETHAMBUTOL may be omitted for some patients with non-cavitatory
smear negative PTB who are known to be HIV-negative and children
with primary TB

12. Treatment categories and sputum examination
schedule under RNTCP
• Treatment categories under RNTCP are CAT-1, 2 &3
• CAT-1 includes:
New sputum smear positive, Seriously ill sputum smear negative,Seriously ill
extra-pulmonary TB
Under CAT-1,2(HRZE)3 and 4(HR) is the standard regimen.
If sputum remains postive at the end of I.P, intensive treatment is continued for 1
more month and continuation phase is started.Sputum is tested at the end of
3rd month and then 5th month and at end of treatment
If sputum is negative,continuation phase is started and sputum tested at end of
treatment.
In any case,if sputum remains postive at the end of 5th month patient is
considered as failure and CAT-2 is started

13. • CAT-2 includes:
Sputum smear postive relapse
Sputum smear postive failure
Sputum smear postive treatment after failure
Others which include sputum smear negative and extra pulmonary
TB relapse and failure.
• The standard regimen is 2(HRZES)3 1(HRZE)3 and 5(HRE)
• If sputum postive after I.P,continue I.p for 1 mother month and start
C.P. Sputum is tested at end of 4th , 6th and 9th month
• If sputum negative after I.p, continuation phase is started and
sputum is tested at 5th month and 8th month

14. • CAT-3 Includes new sputum smear negative and extra pulmonary TB
who are not seriously ill
• The standard regimen is 2(HRZ)3 and 4(HR)3.
• Sputum is tested at end of I.p and
if postive re-register the patient as failure and start CAT-2
If negative,continuation phase is started and sputum tested at end of
treatment

15. Management of patients who interrupt
treatment
• Patient compliance is found to be very less in many parts of world
especially in developing and under-developed countries.
• And so,it is important to know about management of such patients
and the treatment protocols based on length of interruption,period of
treatment used and status of sputum smear.

16. • Management of patients who were smear negative at diagnosis
and who interrupt treatment
• If treatment received before interruption is less than 1 month and
Length of interruption is:
Less than 2 months,no sputum smear test is required,,treatment is resumed
More than 2 months,sputum test is done and if negative,treatment is resumed
but if postive,,patient is registered as new sputum smear postive and CAT-1 is
started afresh
• If treatment received is more than 1 month and length of interruption is:
Less than 2 months ,no sputum smear is required and treatment is resumed
More than 2 months,sputum is tested,,if negative treatment is resumed but if
postive,,Patient is registered as treatment after default and CAT-2 is started

17. •Management of sputum postive cases who interrupt treatment
If treatment received is less than 1 month and length of interruption is
• Less than 2 weeks,no sputum smear test is required and Treatment can be
resumed with CAT-1
• 2-7 weeks,no sputum test is required but treatment is started afresh with CAT-1
• More than 8 weeks,sputum test is done and if:
Postive,re-registered as new case and CAT-1 started afresh
Negative,resume cat-1 treatment
If treatment received before interruption is 1-2 months and length of interruption
is less than 2 weeks then no Sputum smear examination is required and CAT-1
treatment can be resumed

18. • If treatment received is more than 2 months and length of
interruption is:
Less than 2 weeks,sputum smear is not done,treatment is
resumed
2-7weeks, sputum smear is done and if postive,I.P is given for 1
extra month ,,if negative,CAT-1 is resumed,,
More than 8 weeks,,sputum smear is done and if postive,,CAT-2
is started,,If negative,,CAT-1 is resumed

19. • Management of sputum postive retreatment cases who interrupt
treatment
• If treatment received before interruption is less than 1 month and length
of interruption is:
Less than 2 weeks,no sputum test is required and treatment continued
with CAT-2
2-7weeks,no sputum test is required but CAT-2 started afresh
More than 8 weeks,sputum test up is done,,if postive—CAT-2 is started
afresh,,,if negative– CAT 2 is resumed

20. • If treatment received before interruption is 1-2 months and period of
interruption is:
Less than 2 weeks,,sputum test is not required and CAT 2 continued
2-7weeks,,sputum test is done,,and if postive,,I.P is given for 1 extra
month but if negative CAT 2 resumed
More than 8 weeks,sputum test is done,,if postive,,CAT-2 started
afresh,,if negative,,CAT-2 resumed

21. • If treatment received before interruption is more than 2 months and
period of interruption is:
Less than 2 weeks,no sputum test is required and CAT-2 is resumed
2-7 weeks,sputum test is done,if postive,,CAT-2 started afresh,,if
negative CAT-2 resumed
More than 8 weeks,,sputum test is done and if postive,,CAT-2 is started
afresh and if negative CAT-2 is resumed

22. TREATMENT OF MONO-DRUG resistant PTB
• For those with streptomycin resistance,it is obviously reasonable to stick to conventional short course
regimens
• For patients with isoniazid resistant TB ,following two approaches have been recommended:
1) Continuation of R,E&Z for a further 10months or R+E for 12 months after having administered HRZE
for initial 2 months
2)No modification of initially administered four drug regimen with it being given throughout the 6month
period is another approach.
If patients are already known to have isoniazid resistance at commencement of therapy,a nine month
regimen comprising of 2SRZE and 7ER is recommended
• For patients with rifampiicin resistance, a rare occurrence except in HIV PATIENTS regimen comprising
of HZE for 18-24 months has been recommended although some studies showed that duration of
treatment can be reduced to 9-12 months with addition of fluoroquinolone to this three drug regimen

23. Treatment of MDR-TB
• A patient with MDR-TB should receive a regimen comprimising at
least four to five of these SLD for initial months followed by three to
four drugs subsequently
• One regimen recommended by WHO consists of treatment with
ETHAMBUTOL,ETHIONAMIDE,PROTHIONAMIDE,OFLOXCIN OR
CIPROFLOXCIN,PYRAZINAMIDE AND
AMINOGLYCOSIDE,CAPREOMYCIN for first 6 months followed by first
four drugs being administered for a further 12 to 18 months
• The optimum duration of patients with MDR-TB is unclear although
WHO along with other authorities has recommended a minimum of
18month regimen

24. RNTCP AND MDR-TB
• RNTCP is using a Standardised Treatment Regimen (Cat IV) for the treatment
of MDR-TB cases (and those with rifampicin resistance) under the programme.
Cat IV regimen comprises of 6 drugs- kanamycin, ofloxacin (levofloxacin)†,
ethionamide, pyrazinamide, ethambutol and cycloserine during 6-9 months of
the Intensive Phase and 4 drugs- ofloxacin (levofloxacin), ethionamide,
ethambutol and cycloserine during the 18 months of the Continuation Phase.
• p-aminosalicylic acid (PAS) is included in the regimen as a substitute drug if
any bactericidal drug (K, Ofl, Z and Eto) or 2 bacteriostatic (E and Cs) drugs are
not tolerated.

25. Treatment of MDR patients who interrupt treatment:
• Cat IV patients in IP/CP who miss doses:
All the missed doses during IP must be completed prior to switching the patient to CP. Similarly all
missed doses during CP must be administered prior to ending treatment.
• Cat IV patients who interrupt treatment for less than 2 months during IP:
When the patient returns to resume treatment the IP will be continued, however the duration of
treatment will be extended to complete IP
• Cat IV patients who interrupt treatment for less than 2 months during CP:
When the patient returns to resume treatment, the CP will be continued, however the duration of
treatment will be extended to complete the CP. The follow up cultures will be done as per the
revised schedule.
• Cat IV patients who default (interrupt treatment for 2 or more months) and return back for
treatment:
Such patients will be given an outcome of “default” and then will be re-registered for further
treatment which is based on the duration of default.

26. • If period of default is less than 6 months and treatment duration prior
to default is:
Less than 3 months,,re-register and start CAT-4 afresh
If 3months- End of IP,,AFB Culture is done and if postive then re-start
CAT-4 and sensitivity for 1st line and 2nd line TB drugs is done,,if
negative continue I.P, Repeat culture and start C.P
If more than 3 months and during C.P, AFB culture is done,,if negative
C.P is continued,,if postive DST FOR 1st and 2nd line is done and
individual regimen is formulated

27. • If period of default is more than 6 months then culture is done.
• If culture is postive,then DST for FLD &SLD is done,,if MDR,then CAT-4
is started afresh after re-registering the patient,,if XDR,then CAT-5 is
started
• If culture is negative,no treatment is required but patient is followed
up periodically