Ph-Ch6: General concepts in TB Treatment

The goals of tuberculosis treatment are:

• Rendering the patient non-infectious, breaking the chain of transmission and decreasing the infection​ pool

• Decreasing case fatality and morbidity by ensuring relapse-free cure

• Minimising and preventing the development of drug resistance.  ​

To meet the goals of treatment, the regimens should be:

• Safe, easy to administer and aid treatment adherence
• Long enough to achieve the long-term cure of the disease, and short enough to increase patient compliance.

Any treatment regimen which reduces the pill count but increases the overall treatment success is an ideal regimen to meet the goals of tuberculosis treatment.  

Resources

• Training Modules (1-4) for Programme Managers and Medical Officers, 2020.

Assessment

​

Under the National TB Elimination Programme (NTEP), strategies adopted in the treatment of TB are based on the available scientific and operational researches. These strategies are combined to ensure better treatment outcomes for the TB patients. The main strategies include:

Domiciliary Treatment

• This is a strategy that allows for the treatment of TB in a patient’s home.
• Domiciliary chemotherapy proved to be as effective as sanatoria treatment (which was the historical way of treating TB) and achieved higher cure rates.
• The patients having the social benefits of being at home. 

Short Course Chemotherapy (SCC)

• Chemotherapy of TB underwent revolutionary changes in the 70s owing to the availability of two well-tolerated and highly effective drugs – rifampicin and pyrazinamide.
• These drugs allowed for SCC and made it possible to simplify treatment and reduce its duration without reducing the therapeutic effect.
• Now with SCC regimens, it is possible to treat and cure TB patients in 6 months.
• When given daily, these regimens are effective, achieve high cure rates, prevent the emergence of drug resistance and minimize relapses.
• The shorter duration also contributes to improvement in treatment adherence.

Directly Observed Treatment (DOT)

DOT is a method whereby a trained healthcare worker or another trained designated person (treatment supporter) watches a patient swallow each dose of anti-TB drugs and document it.

• DOT can reduce the development of drug resistance, treatment failure, or relapse after the end of treatment.
• Many patients who do not receive directly observed treatment stop taking drugs once they feel better.
• Hence, by providing DOT, the NTEP ensures that patients receive the right drugs, in the right doses, at the right intervals and for the right duration.

The modern treatment strategy is based on standardized short-course chemotherapy regimens largely administered on a domiciliary basis, utilising the DOTS strategy and proper case management to ensure completion of treatment and cure.

Resources

• Training Modules (1-4) for Programme Managers and Medical Officers, 2020.
• Treatment of Tuberculosis Disease, CDC, 2006.
• Guide on Tuberculosis Control for Primary Health Care Providers, WHO, 2015.
• Treatment of Tuberculosis: Guidelines for National Programmes, WHO, 2003.

Assessment

Tuberculosis treatment and its different regimens have scientific backgrounds for their formulations. To understand this, we need to know about the mode of action of each anti-TB drug first.

Mode of Action of Anti-TB Drugs

Anti-TB drugs have the following three actions:

1. Early bactericidal activity: Killing of actively growing bacilli (in the phase of rapid multiplication and uninhibited metabolic activity).
2. Sterilizing activity of persisting bacilli, i.e., metabolically inhibited organisms in a quasi-dormant state.
3. Ability to prevent the emergence of drug resistance.

The ranking of first-line drugs with respect to their type of activity is indicated in Table 1 below.

Table 1: Ranking of first-line anti-TB drugs used in the treatment of drug-sensitive TB, based on the mode of action and activity

Thus, each drug has unique characteristics and drug combinations will make the regimen more effective.

Need for Long Duration of Treatment of TB

• Anti-TB drugs mostly kill actively multiplying tubercle bacilli.
• When bacilli have low metabolic activity, i.e., when bacterial growth has almost come to a standstill and the organisms are “dormant”, they are not killed by otherwise bactericidal drugs. Such organisms are referred to as persisters*.
• Though they may survive in the presence of drugs, behaving as if they were drug-resistant, they are in fact susceptible to the drugs.
• Thus, if for some reason these organisms regain their ability to multiply freely, they would be killed by the very drugs that had not harmed them before.
• When dormant bacilli again become metabolically active and start multiplying during effective chemotherapy, they are soon killed.
• Once chemotherapy has been completed, the revived bacilli may continue to multiply and thus cause relapse.
• This explains why conventional chemotherapy needs to be of long duration.

Resources

• Training Modules (1-4) for Programme Managers and Medical Officers, 2020.
• Tuberculosis Case-finding and Chemotherapy: Questions and Answers, K. Toman.

 Assessment

Standard TB Treatment is divided into two phases

• Intensive Phase(IP): In this phase,
  • Kills most of the TB bacteria during the first 8 weeks of treatment, but some bacteria can survive longer
  • Therefore, more drugs are administered to kill the bacteria and reduce the severity of disease.
  • Treatment in this phase usually is of short duration(2 to 6 Months or more) in comparison to Continuation Phase(CP)

• Continuation Phase(CP): In this phase,
  • All the remaining TB bacteria are in the dormant stage i.e., stage when growth and development of bacteria are temporarily stopped.
  • Therefore, fewer but powerful antibiotics are administered to kill those bacteria. 
  • Treatment in this phase usually lasts longer than Intensive Phase(IP)(4 to 18 Months or more)

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Fixed-dose combinations (FDCs) are drug formulations where two or more drugs are combined physically into one formulation such as a tablet or pill.

This is more convenient to the patients taking medicines and it also simplifies the supply chain.

Resources:

• Technical and Operational Guidelines for TB Control in India 2016

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Fixed-Dose Combination(FDC) provides a simple approach to deliver the correct number of drugs at the right dosage as all the necessary drugs are combined in a single tablet. By altering the number of pills according to the patient’s body weight, complete treatment is delivered without the need for calculation of dose

Figure: Advantages of Fixed Dose Combination(FDC)

A regimen means a prescribed systematic form of treatment for a course of drug(s). For TB treatment, Multi drug combination of regimen is followed. 

All TB drug regimens have an initial intensive phase(IP) followed by a continuation phase(CP). 

Following are some of the main TB drug regimens used based on the drug resistance pattern detected for TB patients.

• First-Line Anti TB Drugs(Prescribed for Drug Sensitive TB DS-TB)
  • Daily weight band wise FDC

• Second-Line Anti TB Drugs (Prescribed for Drug Resistance TB - DR-TB)
  • H Mono Poly Regimen
  • Shorter oral Bedaquiline containing MDR-TB regimen
  • Longer oral Bedaquiline containing regimen
  • Shorter injectable containing MDR-TB regimen

To know the TB treatment response and to determine that if patient is cured, TB patients are clinically evaluated at the end of every four weeks of treatment, and they are also followed up by performing sputum test at end of each treatment phase (i.e. Intensive phase and Continuation phase)

TB patients during clinical evaluations are assessed to

• Identify possible adverse reactions to medications;
• Check for any comorbid conditions;
• Weight change;
• monitor adherence; and determine treatment efficacy by observing their symptoms

Although each patient responds to treatment at a different pace, all TB symptoms should gradually improve and eventually go away.

Patients whose symptoms do not improve during the first 2 months of treatment, or whose symptoms worsen after improving initially, should be re-evaluated for adherence issues and development of drug resistance.

After completion of TB treatment, all patients should be followed up at the end of

• 6 months,
• 12 months,
• 18 months &
• 24 months

TB patients at the follow up should be screened for any clinical symptoms and/or cough. If found positive on screening, then sputum microscopy and/or culture should be considered. This is important in detecting the recurrence of TB at the earliest.

After completion of TB treatment, if the patient has not developed any clinical symptoms and/or cough and also if the microscopy remains negative during their follow up, then the patient is considered as “Relapse Free Cure from TB.”

When a TB patient consumes all the doses under the prescribed regimen, then Treatment Outcome is declared for a Patient.

Treatment success is considered when a TB patient either Cured or Treatment completed is accounted in treatment success

Adverse Drug Reactions(ADR) are unwanted or harmful reactions experienced following the use of a drug or combination of drugs and are suspected to be related to a drug. Severity of adverse effects varies from tolerable and mild ADRs to serious and life threatening ADRs.

Figure: Various Adverse Drug Reactions

Common ADR Symptoms:

• Pain in upper abdominal area, with loss of appetite
• Nausea – Uneasy feeling with inclination to vomit, after having the drugs
• Gastritis – Burning sensation in lower chest region, bloating sensation, sourness in mouth
• Diarrhoea - Loose stool(2-3 in a day)

Adverse Drug Reactions(ADR) are classified into serious and non-serious ADR depending upon the intensity of symptoms experienced by the patient. Below is the brief overview

1. Counsel and reassure the patient as the common occurring adverse effects usually resolve with time.
2. Advise the patient to take all the drugs together.
3. Advise patient to take light meal (biscuits, bread, rice etc.) before taking drugs.
4. Inform patients that they may take drugs embedded in banana or at the bedtime to reduce their associated side effects.
5. Encourage patients to keep themselves hydrated by increasing fluid intake.
6. Provide ORS (Oral Rehydration Solution) to counter dehydration due to loose motion and vomiting.

Figure: Referral to PHI for ADR

Resources:

• Training Guide for Peripheral Health Workers on Adverse Drug Reactions

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The Tuberculosis Treatment Card is a paper-based recording form that is kept in the institution treating the TB patient under the National TB Elimination Programme (NTEP). It is a pre-requisite documentation related to treatment services offered to TB patients under NTEP.

Uses of the TB Treatment Card

The TB treatment card is primarily used for:

1. Documenting administered drugs with their dosages
2. Documenting follow-up investigation results
3. Monitoring adherence to treatment
4. Recording adverse events
5. Recording treatment outcomes

There are two pages in the TB treatment card and details in each page is delineated in the table below.

Important Points to Note

• The TB treatment card is filled at the Peripheral Health Institution (PHI) when a patient is initiated on treatment.
• The original TB treatment card is kept at the PHI and updated fortnightly.
• A duplicate treatment card is to be given to the treatment supporter for documentation of daily events. 
• The treatment supporter should be trained on how to record the treatment card. 
• Details on the patient’s HIV status are not included in the treatment supporter’s copy to maintain confidentiality.

The figure below shows the 1^st page of the TB treatment card. Click here to access the full form in the NTEP Training Modules 1-4 for Programme Managers & Medical Officers, p. 223.

Figure: First Page of the TB Treatment Card; Source: NTEP Training Modules 1-4 for Programme Managers & Medical Officers, p. 223

Resources

• NTEP Training Modules 1-4 for Programme Managers & Medical Officers, 2020.

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In the National TB Elimination Programme (NTEP), the ‘NTEP TB identity card’ is provided for their identification and record of clinical follow-ups.

The identity card is completed for each patient who has a Tuberculosis (TB) Treatment Card, and it is kept with the patient. Information from the TB Treatment Card is used to complete the identity card.

There are 3 parts in the NTEP TB identity card and details in each part is delineated in Table 1.

The information contained in this card will help to continue treatment in case the patient is transferred or admitted to any other health facility any time during the treatment period. The TB identity card is shown in Figure 1.

Figure 1: NTEP TB Identity Card; Source: NTEP Training Modules 1-4 for Programme Managers & Medical Officers, 2020

Resources

• NTEP Training Modules 1-4 for Programme Managers & Medical Officers, 2020

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TB patients may not stay in one place throughout the treatment duration. When they move from one place to other, there should be a mechanism to hand over the responsibility of continuing the patient's treatment in a facility near the new place of the patient. This is the concept of patient transfer and can be easily managed in Nikshay portal.

• The transfer module in Nikshay enables transfer requests of patients between Health Facilities (HFs) across the country.
• Provision of shifting of patient from one HF to another is possible if the patient changes his/her residence for the purpose of treatment.
• The requests are of two types: “Transfer In” and “Transfer Out”.
• All transfer requests needs to be accepted by the “District/ TB Unit (TU)/ Peripheral Health Institute (PHI)” where the transfer request is made in order for it to take effect.
• Transfer requests can be made to even the District/ TU level. However, it can be completed only once the “Transferred to PHI” has been assigned.

Figure: Transfer Management in Nikshay; Source: Nikshay Zendesk, Nikshay Knowledge Base, Advanced Transfer in Web.

Steps in Transfer of TB Patient

1. In Nikshay, the referring HF updates details from the current HF of patient to the HF where patient is being transferred.

2. The receiving HF gets the intimation about the transfer.

The patient transfer module also provides the provision to pull the patient belonging to another HF to the recipient HF. The accountability of the transferred patients is now with the receiving HF and the treatment initiating facility.

A separate transfer register is also available to get details about various transfers from and to a given district, which can be downloaded from Nikshay reports.

Resources

• Nikshay Zendesk, Nikshay Knowledge Base, Advanced Transfer in Web.
• Guidelines for PMDT in India, 2021.

Assessment

​The management principles of Extrapulmonary Tuberculosis (EPTB) are shown in the figure below.

Figure: Ten principles about what every EPTB patient in India needs as a basic standard of care

Abbr: CBNAAT:Cartridge-based Nucleic Acid AMplification Test; PTB: Pulmonary TB; NTEP: National TB Elimination Programme

Diagnosis of EP-TB

• All efforts need to be made to get a microbiological confirmation whenever a sample is available. 
• Clinical diagnosis can be made by treating physician based on the clinical features, lab investigations, imaging studies and by ruling out other causes

Treatment Regimen and Duration for EPTB

The treatment regimen and schedule for EPTB cases will remain the same as for pulmonary TB (2HRZE/ 4HRE). However, the duration of the continuation phase in EPTB may be extended in special situations such as TB Meningitis, bone and spine TB etc.

Role of Surgery in EPTB Cases

• Surgery is sometimes required for the diagnosis of EPTB. It is reserved for management of late complications of the disease.

Monitoring Treatment Response

• Response to treatment in EPTB may be best assessed clinically. Clinical follow-up is the most important criterion for the follow-up of EPTB patients. The clinician can assess the patient’s condition by checking weight gain and a decrease/ increase in presenting clinical symptoms.
• Investigations such as Acid-fast Bacilli (AFB) microscopy, chest X-ray, liver function tests, serum creatinine, and USG-abdomen can be used to monitor the treatment status.

The treatment support and other monitoring activities remain the same as for pulmonary TB.

Resources

• Training Modules (1-4) for Programme Managers and Medical Officers, 2020.
• Index TB Guidelines on Extra-pulmonary Tuberculosis for India, Central TB Division, 2016.

Assessment

Treatment interruption is defined as a patient-initiated episode in which the patient discontinues TB treatment. All efforts must be made to ensure that TB patients do not interrupt treatment or are not lost to follow-up. Action should be taken to promptly retrieve patients who fail to come for their daily dose by the treatment supporter

The management of treatment interruptions is made based on the following criteria:

i. Type of case: Whether new, relapse or failure

ii. Duration of treatment taken: Less than one month/ more than one month. This helps in assessing the risk of the presence of drug resistance.

iii. Duration of Interruption: Less than one month/ more than a month.

If treatment interruption is more than one month, the outcome is declared as ‘lost to follow up’.

If a patient returns to the health facility after interrupting treatment for more than one month, the patient sample needs to be subjected to Drug Susceptibility Testing (DST) to determine resistance/ sensitivity status to anti-TB drugs.

In case the interruption is for less than one month, the same treatment regimen is completed to complete all doses.

Modes of Retrieval

TB treatment is supervised by a trained treatment supporter (a health worker, family member or community volunteer). The residential address is verified for all TB patients by home visits. However, in case of treatment interruption, patient retrieval action is required.

Retrieval can be done by the following modes:

1. Retrieval of patients interrupting treatment within 24 hours of discontinuation is done by the Treatment Supporter (TS) or Accredited Social Health Activist (ASHA)/ Auxilliary Nurse Midwife (ANM)/ Multipurpose Worker (MPW). The reason for interruptions should be reviewed carefully and efforts made to counsel and bring the patient back for treatment.

2. If the TS is not successful in retrieving such patients, it should be reported to the next higher level of supervisors, like Senior Treatment Supervisor (STS), and they should take all efforts to counsel and retrieve the patient.

3. If the patient interrupts treatment on more than one occasion, the Medical Officer of the Peripheral Health Institute (MO-PHI) should visit the patient’s home. The MO-PHI should give intensive counselling to the patient and may provide additional support to continue the treatment without interruption.

4. Innovative use of information and communication technologies for treatment adherence monitoring through 99 DOTS, Medication Event Reminder Monitor (MERM), etc. are also beneficial in finding missed doses and initiating retrieval action by the health staff.

Resources

1. Training Modules (1-4) for Programme Managers and Medical Officers.

2. Guidelines for PMDT in India, 2021.

Assessment

There are five principal ways to prevent Drug-resistant Tuberculosis (DR-TB), as given in the figure below.

Image

 Figure: Five Principal Ways to Prevent DR-TB; Source: Guideline for PMDT in India, 2021.

• Drug resistance cannot be prevented by mere diagnosis and treatment of DR-TB.
• Basic TB diagnostic and treatment services should receive priority for the prevention of drug resistance.
• Systems for early detection and treatment of DR-TB should be integrated into the existing TB services and the general health system.
• Healthcare facilities and congregate settings should be provided with proper infection control measures.
• Transmission should be prevented by addressing non-specific determinants like access to care, comorbidities and awareness.

Resources

• Guidelines for PMDT in India, 2021.
• Companion Handbook to the WHO Guidelines for the Programmatic Management of Drug-resistant Tuberculosis.

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The suggested treatment regimen covering maximum non-Mycobacterium Tuberculosis (NTM) mainly Mycobacterium Avium Complex (MAC) is as follows: 

• Rifampicin (R) 450-600 mg OD
• Ethambutol (E) 800-1200 mg OD
• Clarithromycin (Clr) 1 gm OD (split into two doses)
• Add injection Amikacin (Am) 750 mg – 1 gm thrice weekly for the first 2-3 months

Intensive Phase (IP) is for 3 months and can be extended to a maximum of 6 months with all four drugs. 

Continuation Phase (CP) of treatment will be with the same drugs except for injectable. This should be continued for 12 months after sputum culture conversion. Drugs will be given as per the standard weight bands.

If the patient does not culture convert by end of 3 months, then species identification and Drug Susceptibility Testing (DST) are required for further management. 

Management of complicated/ invasive TB disease:

• Recommended initial regimen for most patients with nodular/ bronchiectatic MAC lung disease:
  • Thrice-weekly regimen including Clarithromycin 1000 mg or Azithromycin 500 mg, Ethambutol 25 mg/kg, and Rifampicin 600 mg administered three times per week.
• Recommended initial regimen for fibro-cavitary or severe nodular/ bronchiectatic MAC lung disease: 
• Clarithromycin 500-1000 mg/day or Azithromycin 250 mg/day, Ethambutol 15 mg/kg/day, and Rifampicin 10 mg/kg/day (maximum, 600 mg). 

Points to Note

• Intermittent drug therapy is not recommended for patients who have a cavitary disease, patients who have been previously treated, or patients who have moderate or severe disease.
• The primary microbiologic goal of therapy is 12 months of negative sputum cultures while on therapy; therefore, sputum must be collected from patients for Acid-fast Bacilli (AFB) examination throughout treatment on monthly basis in IP and quarterly basis in CP after culture conversion is achieved.
• Given these complexities, the treatment of NTM will be the prerogative of the Nodal Drug-resistant TB Centres (NDR-TBCs).

Resources

• Training Modules (1-4) for Programme Managers & Medical Officers (NTEP), 2020.
• British Thoracic Society Guidelines for the Management of Nontuberculous Mycobacterial Pulmonary Disease, 2017.
• Guidelines for Programmatic Management of Drug-resistant Tuberculosis in India, March 2021.

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