Tuberculosis Treatment Course (DOTS Therapy): TB Drugs List and Side effects

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Tuberculosis Treatment is carried out using the DOTS Therapy which stands for Directly Observed Treatment Short course. The DOTS therapy makes use of antituberculosis drugs over a specified period of time under observation as patients may not comply with drugs which leads to multidrug resistant tuberculosis. The DOTS TB treatment therefore combats resistance.

Can Tuberculosis be cured completely?

Tuberculosis can be cured completely when there is compliance with drugs and when it is detected early enough for Treatment to be commenced before any complication develops. Once there is complication, cure for TB can be achieved but some complications may be permanent and can only be alleviated.

Aims of Tuberculosis Treatment

  1. In order to achieve cure for TB
  2. To prevent death from active TB
  3. To prevent complications
  4. To prevent relapse of TB
  5. To reduce transmission of TB to other people
  6. To prevent the development of TB drug resistance, which is a major cause of Multidrug resistant TB

Please note that active tuberculosis treatment should not be initiated with single drug as resistance may occur.

Tuberculosis Treatment Guidelines

  1. All recommended tuberculosis treatment regimen has 2 phases: the Initiation phase or Intensive phase and Continuation Phase.
  2. The initial intensive phase is aimed at killing actively growing and semi-dormant tubercle bacilli
  3. At least 2 bactericidal drugs such as Isoniazid (INH) and Rifampicin are necessary in the initiation phase
  4. Pyrazinamide given in the initial intensive phase allows the duration of treatment to be reduced from 9 to 6 months.
  5. Addition of Ethambutol is of benefit when initial drug resistance is suspected or where the burden of organism is high.

Continuation phase aims to eliminate most residual bacilli and reduces numbers if failures and relapse

TB Drugs List and their abbreviations

  1. Rifampicin (R)
  2. Isoniazid (H)
  3. Ethambutol (E)
  4. Pyrazinamide (Z)
  5. Streptomycin (S)
  6. Capreomycin
  7. Kanamycin
  8. Viomycin
  9. Ethionamide
  10. Rifabutin
  11. Ciprofloxacin
  12. Ofloxacin
  13. Rifapentin
  14. Cycloserine

Classification of Anti tuberculosis drugs

  1. First line TB drugs
  2. Second line TB drugs

DOTS Standard TB Drugs Treatment Combination and Duration

In all cases of Tuberculosis the Standard treatment is applied with addition of few drugs such as: addition of Steroid to Genitourinary TB and Central Nervous system TB. Miliary TuberculosisPulmonary TB and other forms of Extrapulmonary TB all follow the standard treatment outlined below.

Standard 6 months short course chemotherapy

This involves 2 months Intensive phase through the use of:

  • Streptomycin or Ethambutol,
  • Isoniazid,
  • Rifampicin
  • and Pyrazinamide

And 4 months Continuation Phase through the use of

  • Isoniazid
  • Rifampicin

Standard 9 months short course chemotherapy

This involves 2 months Intensive phase through the use of:

  • Streptomycin or Ethambutol,
  • Isoniazid,
  • Rifampicin
  • and Pyrazinamide

And 7 months Continuation Phase through the use of

  • Isoniazid
  • Rifampicin
DOTS Tuberculosis drugs treatment for different types of extrapulmonary TB
DOTS Tuberculosis drugs treatment for different types of extrapulmonary TB

 

First Line TB Drugs Dosage and their Side Effects

These are the recommended drugs used in combination as the first in the treatment of active tuberculosis.

Isoniazid Dosage and Side Effects

Isoniazid Dosage

Daily dose of 5 mg/kg oral (maximum 300mg) or (900mg twice weekly or 600mg thrice weekly).

Isoniazid Side effects

  1. It can cause drug induced Hepatitis
  2. Can cause peripheral neuritis
  3. Drug induced lupus
  4. May cause seizures
  5. Hypersensitivity with rash and fever
  6. Involved in drug interactions with dilantin and disulfiram

Rifampicin Dosage and Side effects

Rifampicin Dosage

10 mg/kg oral (maximum 600mg)

Rifampicin side effects

  1. Orange body secretions
  2. Flu-like syndrome
  3. Drug induced hepatitis
  4. Thrombocytopenia which may cause abnormal bleeding
  5. Nausea, anorexia and diarrhea
  6. Renal failure
  7. Multiple drug interactions

Pyrazinamide Dosage and Side effects

Pyrazinamide dosage

25 to 30mg/kg orally/daily or 30-35 mg/kg weekly

Pyrazinamide Side effects

  1. Hyperuricemia
  2. Drug induced Hepatitis
  3. Body Rash
  4. Nausea and anorexia

Ethambutol Dosage and adverse effects

Ethambutol dosage

  • 25mg/kg daily (orally) for initial 2months of treatment and then 15mg/kg orally for the rest of treatment period
  • Or 50 mg/kg twice weekly or 30mg/kg thrice weekly

Ethambutol Side effects

  1. Optic neuritis
  2. Gastrointestinal discomfort

Streptomycin Dosage and adverse effects

Streptomycin Dosage

  • 15mg/kg given intravenously or intramuscularly (up to a maximum of 1.0g) daily for 5days in a week
  • Or 5mg/kg (maximum 1.5g) twice weekly or thrice weekly

Streptomycin side effects

  1. Ototoxicity
  2. Vestibular dysfunction
  3. Nephrotoxicity
  4. Skin rash
  5. Hypersensitivity reactions

Mechanisms of actions of Essential Antituberculosis drugs

Anti-tuberculosis drugs have 3 main properties: they have bactericidal activity, Sterilizing activity and the ability to prevent resistance to treatment.

  1. Isoniazid and Rifampicin are the most potent of the essential antituberculosis drugs that are active against all populations Rifampicin being the most potent.
  2. Pyrazinamide is most active in acidic environment
  3. Streptomycin is bactericidal in nature and acts against rapidly multiplying TB bacilli
  4. Ethambutol and Thiacetazone helps to prevent resistance

First line Tuberculosis Drugs

  1. Rifampicin
  2. Isoniazid
  3. Ethambutol
  4. Pyrazinamide
  5. Streptomycin

These 4 drugs for TB that are commonly used as first line TB Drugs. This means when you have tuberculosis, these drugs are used first to treat the TB; if it becomes resistant to treatment, then the second line TB drugs can be used.

Second Line TB Drugs list

  1. Cycloserine
  2. Thioamides such as Ethionamide and Prothionamide
  3. Aminoglycosides: examples include Capreomycin, Viomycin and Kanamycin
  4. Fluoroquinolones : examples include Ciprofloxacin and Ofloxacin
  5. Other newer TB drugs include Rifabutin and Rifapentin

DOTS Plus TB management

The DOTS Plus is a strategy for management of cases with multi-drug resistant tuberculosis. It was developed by WHO and partner agencies in 1999 based on the same principle with DOTS.

The DOTS plus includes the use of sputum culture and drug susceptibility test for diagnosis of TB and uses both first line drugs and second line drugs like Ethionamide, Capreomycin, Thiacetacone and Fluoroqiunolones.

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