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TB Treatment Regimen. Gina S. de los Reyes, M.D., FPCP, FPCCP. Outline. Short Course Treatment; Fixed Dose Combination Classification of TB Cases Treatment Regimens Treatment of TB in Special Situations Symptom-based approach to adverse effects of TB drugs. Who requires treatment for PTB?.
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TB Treatment Regimen Gina S. de los Reyes, M.D., FPCP, FPCCP
Outline • Short Course Treatment; Fixed Dose Combination • Classification of TB Cases • Treatment Regimens • Treatment of TB in Special Situations • Symptom-based approach to adverse effects of TB drugs
Who requires treatment for PTB? 1. Active PTB (Class 3) 2. Inactive PTB (Class 4) but with no previous adequate/completed treatment 3. TB suspect (Class 5) when the probability of TB is high, while awaiting confirmation
Aims of Treatment 1. To cure patients with the least interference with their lives. 2. To prevent death in seriously ill patients. 3. To prevent extensive damage to the lungs with the consequent complications. 4. To avoid relapse of the disease. 5. To prevent the dev’t of drug-resistant T.B (acquired resistance). 6. To protect his/her family and the community from infection.
Anti-TB drugs : Actions & Adverse EffectsFirst line drugs Drug Action Adverse Effects Isoniazid Bactericidal Hepatitis Peripheral Neuropathy Rifampicin Bactericidal Gastro’nal Cutaneous rxn Hepatitis
Anti-TB drugs Ethambutol Bacteriostatic Retrobulbar neuritis Pyrazinamide Bactericidal Hepatotoxicity Arthralgia Streptomycin Bactericidal Ototoxicity Cutaneous Hypersen- sitivity
Second-line drugs • Ethionamide • Prothionamide • Sodium para-aminosalicylate (PAS) • Cycloserine • Ofloxacin • Ciprofloxacin • Capreomycin • Kanamycin • Viomycin • Amikacin • Co-amoxiclav • Clarithromycin • Rifamycin derivatives-Rifabutin, Rifapentene
Drug Doses Dosage in mg/kg (range) Drug Daily Thrice/week Isoniazid 5 10 (4-6) (8-12) Rifampicin 8 10 (8-12) (8-12)
Drug Doses Pyrazinamide 25 35 (28-30) (30-40) Ethambutol 15 30 (15-20) (25-35) Streptomycin 15 15 (12-18) (12-18)
FIXED- DOSE COMBINATION (FDC) ANTI-TB DRUGS • Formulation where two or more anti-TB drugs are present in fixed proportions • Advocated by WHO & the International Union Against Tuberculosis & Lung Diseases (IUATLD) to replace single-drug preparations as treatment for TB
FDCs • For the patient: simplified drug intake • Fewer pills to swallow • Pills are identical • Correct regimen is followed
FIXED DOSE COMBINATION: SIMPLER DOSE COMPUTATION Practical dosing: < 55 kg: 3 tablets daily > 55 kg: 4 tablets daily
Short Course Chemotherapy • 6 months regimen which includes Rifampicin and Pyrazinamide • Standard Treatment- at least 12 months (w/o Rifampicin)
2 Phases of SCC Intensive phase- 2 months Continuation phase- 4 months
Short Course Chemotherapy Advantages Easy to take Pt feels better quickly Sputum becomes (-) quickly Relapse rate lower If relapse occurs, TB remains sensitive Much cheaper than standard tx
Objectives of SCC • To achieve better bactericidal and sterilizing activities • To prevent emergence of resistance
Resistant Mutants • Small number which are naturally resistant • More will occur in TB cavity • If only one drug is given the sensitive TB are destroyed but the resistant ones multiply • NEVER GIVE A SINGLE DRUG (MONOTHERAPY)
Classification of TB Cases • Pulmonary TB • Smear (+) • Smear (-) • Extrapulmonary TB
PTB-Smear Positive • At least 2 sputum specimens (+) for AFB • +/- X-ray abnormalities consistent with active TB • 1 sputum specimen (+) for AFB • and with X-ray abnormalities consistent with active TB • 1 sputum specimen (+) for AFB • with sputum culture (+) for M. tuberculosis
PTB – Smear Negative At least 3 sputum specimens (-) for AFB X-ray abnormalities consistent with active TB No response to a course of antibiotics and/or symptomatic medications Decision by a medical officer to treat with anti-TB drugs
Extrapulmonary TB At least 1 mycobacterial smear/culture (+) from an extrapulmonary site (organs other than the lungs: pleura, lymph nodes, gut, skin, joints, bones, meninges, intestines, peritoneum, pericardium, etc) Histological and/ or clinical evidence consistent with active TB & there is decision by a Medical Officer to treat pt with anti-TB drugs
Types of TB Cases New Relapse Failure Return after default (RAD) Transfer-in Other
Types of TB Cases New-pt who has never had tx for TB or who has taken anti-TB drugs for < 1month Relapse- pt. previously treated for TB, has been declared cured or tx completed, and is diagnosed with ( + ) smear or culture for TB Failure- pt while on tx is sputum smear ( + ) at 5 months or later during the course of tx
Types of TB Cases • Return after defaultA patient who returns to treatment with positive bacteriology (smear or culture), following interruption of treatment for 2 months or more. • Transfer-in- pt who has been transferred from another facility with proper referral slip to continue
Types of TB Cases Other 1. Pt starting treatment again after interrupting treatment for >2 mos. and has remained smear (-) 2. Pt who was initially registered as new smear-negative case, turned out to be smear (+) during the tx. 3. Chronic case: pt who is sputum(+) at the end of a re-treatment regimen.
Treatment Regimens Each standard drug is indicated by a capital letter.H- IsoniazidR- Rifampicin Z- PyrazinamideE- Ethambutol S- Streptomycin
Treatment of TB in Special Situations TB in pregnancy/lactation TB in pts with hepatic disease TB in pts with renal disease TB in the elderly TB in HIV/AIDS
Tuberculosis in Pregnancy • INH, Ethambutol & Rifampicin can be used • Not recommended: Pyrazinamide, Streptomycin, Kanamycin, Capreomycin Consensus Statement ( Phil. Practice guidelines Group on Infectious Diseases)
TB treatment in Pregnancy • Non-cavitary Disease -9HRE • Cavitary Disease- 12HRE Consensus Statement ( Phil. Practice guidelines Group on Infectious Diseases)
TB and Lactation • Breast feeding not discouraged • Anti-TB drug concentration - low, non-toxic & non-therapeutic in breast milk Consensus Statement ( Phil. Practice guidelines Group on Infectious Diseases)
TB treatment & Liver Disease • Hepatitis virus carriage or a past hx of acute hepatitis w/o clinical evidence of chronic liver disease Rx- Usual short course chemotherapy • established chronic liver disease • 2SHRE/6HR • 2SHE/10 HE
TB treatment & Liver Disease • Hepatic failure • Streptomycin & Ethambutol can be given. • If a third drug is needed, Isoniazid or Rifampicin can be given cautiously in lowered doses • Acute Hepatitis – defer until hepatitis resolved or • 3SE/6HR
TB treatment & renal insufficiency/ renal failure • Isoniazid, Rifampicin & Pyrazinamide can be given in normal dosages • 2HRZ/6HR
Others • TB in the Elderly • 9HR • TB in HIV + • with susceptibility testing • 2HRZE/4-7HR • w/o susceptibility testing • Non-cavitary- 9HRZE • Cavitary -12HRZE
Symptom-based approach to adverse effects of TB drugs Side-effects (Minor) Drugs responsible Management 1. Gastro-intestinal intolerance Rifampicin Give medication at bedtime 2. Mild skin reactions Any kind of drugs Give anti-histamine 3. Orange/red Colored urine Rifampicin Reassure the patient
Side effects Drug(s) responsible Management 4. Pain at injection site Streptomycin Warm compress; Rotate sites of injection Pyridoxine (Vit B6) 100-200 mg for tx; 10mg for prevention 5. Burning sensation of the feet Isoniazid
Side effects Drug(s) responsible Management 6. Arthralgia Pyrazinamide Aspirin or NSAID Allopurinol Antipyretics 7. Flu-like symptoms (fever, inflammation of the resp. tract) Rifampicin
Major side effects Drug(s) responsible Management 1. Severe skin rash due to hypersensitivity Any kind of drugs (esp Strep) Discontinue Anti-TB drugs 2. Jaundice due to hepatitis Any kind of drugs (esp Isoniazid, Rifampicin and Pyrazinamide D/C anti-TB drugs If sx subside, resume tx and monitor
Major side effects Drug(s) responsible Management 3. Impairment of visual acuity & color vision (optic neuritis) Ethambutol Discontinue Ethambutol & refer to an opthalmologist 4. Hearing impairment, tinnitus, vertigo Streptomycin Discontinue Streptomycin
Challenge doses for detecting cutaneous or hypersensitivity to anti-TB drugs Drug Challenge Doses Day 1 Day 2 Isoniazid 50mg 300mg Rifampicin 75mg 300mg Pyrazinamide 250mg 1.0g Ethambutol 100mg 500mg Streptomycin 125mg 500mg