ANTIMYCOBACTERIAL 1

Question 1

Definisi antimycobacterial agents?

Answer 1

• Agen yg digunakan utk merawat jangkitan mycobacterial seperti tuberculosis & leprosy
• Memerlukan pengambilan multiple-drug regime utk jangka masa yg panjang

Question 2

Definisi tuberculosis?

Answer 2

• Penyakit berjangkit yang disebabkan oleh Mycobacterium tuberculosis yang menyerang paru-paru serta boleh merosakkan sistem saraf tunjang,sistem kalenjar, sistem peredaran darah & tulang
• Dijangkiti melalui titisan cecair drpd org yg telah dijangkiti

Question 3

Nyatakan & terangkan jenis tuberculosis

Answer 3

(1) Active TB - dijangkiti TB dimana bakteria penyebab TB bersifat aktif, menunjukkan simptom jangkitan TB & berupaya utk merebak
(2) Latent TB - dijangkiti TB dimana bakteria penyebab TB bersifat tidak aktif, tidak menunjukkan simptom jangkitan TB & tidak berupaya utk merebak

Question 4

Nyatakan simptom TB & tanda2 jangkitan

Answer 4

• batuk serius, demam, berpeluh pd waktu malam, letih, sakit dada, hilang berat badan, sakit tulang belakang, kerosakan sendi, hati & buah pinggang gagal berfungsi, kencing berdarah, meningitis

Miliary TB - blh mengancam nyawa apb bakteria TB merebak keseluruh badan & lesion TB wujud dgn byk menybbkan anemia,sgt lemah & perubahan berat bdn scr mendadak

Question 5

Nyatakan cara diagnosis TB

Answer 5

(1)Xray imaging - tompokan putih

(2) Laboratory test :
(a) Pulmonary tb - sampel kahak
(b) Extrapulmonary tuberculosis - sampel dri tmpt yg dijangkiti sprti CSF fluid & pleural fluid

(3) Screening test :
(a) Chest xray
(b) Mantoux test - mengenalpasti tb melalui saiz bengkak stlh disuntik tuberculin

Question 6

Golongan yg berisiko dijangkiti TB

Answer 6

• kontak rapat pesakit tb
• pesakit yg immunocompromised
• pesakit yg salahgunakan dadah & perokok tegar
• pesakit yg tinggal dikwsn sempit, kecil atau kurg pengudaraan udara yg bersih

Question 7

Nyatakan prinsup utk rwtn TB

Answer 7

• kecilkan bil bakteria secepat mungkin
• elakkan bakteria mnjadi rintng trhdp ubat
• rwtn jangka pnjg utk elakkan relapse

Question 8

Terangkan DOTS (directly observed treatment)

Answer 8

• Pesakit TB blh smbuh jika diberi ubat yg tpt dlm tempoh yg secukupnya
• Rwatan utk penyakit TB atau DOTS = 6bulan

(1)Rwtn harian selama 2 bulan = 4 jenis ubat mengikut dos regimen rawatan yg betul dibwh penyeliaan oleh kakitangan perubatan / org lain yg dilantik utk meyediakan rwtn
Cth ubat : Isoniazid (H) + Rifampicin (R) + Pyrazinamide (Z) + Ethambutol (E)

(2) Rwatan seterusnya = 3 kali seminggu selama 4bulan = 2 jenis ubat diambil dibwh penyeliaan
Cth ubat : Isoniazid (H) + Rifampicin (R)

Question 9

Terangkan FDCS (fixed dose combinations)

Answer 9

• 2 atau lebih ubat digabungkan dalam 1 tablet
• Ini meningkatkan compliance kurang bg mengurangkan bil tablet yg perlu diambil

Cth FDCS

(1) Forecox -Trac Film Coated Tab : Isoniazid, Rifampicin, Ethambutol & Pyrazinamide
(2) Akurit-Z Tab : Isoniazid, Rifampicin & Pyrazinamide
(3) Rimactazid 300 Sugar Coated Tab : Isoniazid, Rifampicin
(4) Akurit-4 : Isoniazid, Rifampicin, Ethambutol & Pyrazinamide

Question 10

Xtra Info

Answer 10

• 4 drug combination : Isoniazid 75mg, Rifampicin 150mg, Ethambutol 275mg & Pyrazinamide 400mg tablet
• 3 drug combination : Isoniazid 75mg, Rifampicin 150mg & Pyrazinamide 400mg tablet

Question 11

Kategori bagi antimycobacterial agent

Answer 11

(1) First line
- Isoniazid (isonicotinic acid hydrazide) = Hydra, Isovit
- Rifampicin = Rifadin, Rimactane
- Pyrazinamide = Rifater, Rimstar & Voractiv
- Ethambutol = Myambutol, Etibi, Servambutol
- Streptomycin - Ambistryn-S,

(2) Second line
- Cycloserine = Seromycin
- Amikacin = Amikin
- Capreomycin = Capastat
- Kanamycin = Kantrex

Question 12

Terangkan Isoniazid MOA & Toxicity

Answer 12

MOA :

• Merencat sisntesis dinding sel
• Merencat sisntesis mycoloic acids (komponen dlm bakteria dinding sel)
• Dinding sel tdk dpt dihasilkan
• Bakteria mati

Toxicity :
- Peripheral neuropathy, Central nervous system toxicity, Hepatotoxicity and Steven Johnson Syndrome

Question 13

Terangkan Isoniazid contraindication & side effect & drug interaction

Answer 13

Contraindications :
- acute liver disease, drug induced liver disease

Side effect :
- jaundice, skin rash, hepatitits, anorexia, abdominal pain, burning

Drug interaction :
Increase toxicity = Carbamazepine,Benzodiazepine, Paracetamol, Serotonergic antidepressants, Warfarin & Theophylline
Reduction in Phenytoin & Diazepam levels

Question 14

Terangkan Rifampicin MOA & Contraindication

Answer 14

MOA :

• Merencat sintesis nukelik acid (RNA)
• Mengikat pd RNA polymerase B subunit
• Menghalang proses transkripsi RNA
• RNA tdk dpt dihasilkan

Contraindication :
- Jaundice

Question 15

Terangkan Side effects & Toxicity & Drug Interactions

Answer 15

Side Effects :
- Jaundice, skin rash, hepatitis, anorexia, nausea, abdominal pain, orange or red urine, flu syndrome (fever, chills, malaise, headache, bone pain)

Toxicity :
- Hepatotoksisiti, Bone marrow suppression

Drug Interactions :
Reduction in plasma level of Anti infectives, Ethinylestradiol, norethindrone, Tamoxifen, Levothyroxine, Methadone,Warfarin. Cyclosporine, Corticosteroid,
Anticonvulsant

Question 16

Terangkan Ethambutol MOA & Drug Interaction

Answer 16

MOA :

• Menghalang arabinosyl transferase (encoded by emb)
• Tiada reaksi polymerization dari arabinoglycan
• Gangguan sintesis dinding sel

Drug Interaction :
- Absorption delayed / reduced by Aluminium hydroxide

Question 17

Terangkan Ethambutol Contraindication & Side Effects & Toxicity

Answer 17

Contraindication :
- Optic neuritis

Side effects :
- Visual Impairment

Toxicity :
- Peripheral neuropathy, ocular effect

Question 18

Terangkan Streptomycin MOA & Side Effcets

Answer 18

MOA :

• Merencat sintesis protein
• Bertindak pd ribosom subunit 30s
• Menganggu translation hingga menyebabkan pentafsiran genetik kod yg slh pd rantaian ribosom bakteria & menghasilkn sintesis protein abnormal
• Menganggu translocation tRNA dari tapak A ke tapak P seterusnya menyebabkan pemanjangan rantai polipeptida terhalang & tiada pembentukan rantai polipeptida yg lengkap

Side Effects :
- Skin rash, deafness (no wax on otoscopy), dizziness (vertigo & nystagmus), decreased urine output.

Question 19

Terangkan Contraindication & Toxicity & Drug Interaction

Answer 19

Contraindication :
- Gagal buah pinggang

Toxicity :
Ototoxicity ( kerosakkan koklea/saraf pendengaran) nephrotoxicity (kerosakan buah pinggang)

Drug Interaction :
- Increase ototoxicity & nephrotoxicity when use with :
Aminoglycoside, Amphotericin B, Cephalosporins, Cyclosporin, Cisplatin, Furosemide, Vancomycin

Question 20

Terangkan Pyrazinamide MOA & Contraindication

Answer 20

MOA :

• Bertindak dimembran sel dengan merencat sintesis fatty acid dgn cara merencat fatty acid synthetase
• Menganggu membran potential & penghasilan tenaga
• Digunakan utk membunuh populasi semi dormant tubercle bacilli in acidic environment

Contraindication :
- Severe hepatic imapirment

Question 21

Terangkan Pyrazinamide Side Effects & Toxicity & Drug Interactions

Answer 21

Side Effects :
- Skin rash, jaundice, hepatitis, anorexia, nausea, abdominal pain & joint pains

Toxicity :
- Hepatotoxicity, skin rash

Drug Interactions :
- Excretion may be blocked by probenecid

Xtra Info
- BCG (Basillus Calmette - Guerin) tidak menghalang jangkitan tetapi hanya menguatkan sistem imun