Tuberculosis

Question 1

Describe approach to suspected TB meningitis treatment

Answer 1

1. TBM is a medical emergency thereofre commence empirical rx if high risk of TBM (try to get a sample beforehand)
2. HRZE for 2 months then HR for 10 months (12 mo total)
3. Adjunctive corticosteroids (dexa or pred) for 6-8 weeks for pts who do NOT have HIV

Question 2

Describe diagnostic approach to suspected TB meningitis

Answer 2

1. Consider TBM as differential
2. Exclude other causes of meningitis
   - CSF culture (can take 2-6/52 but gold standard)/microscopy (poor sensitivity, centrifuge)
   - Viral/bacterial PCRs
   - CrAg and other special tests
   - HIV test
3. Look hard for TB in the CNS
   - Lumbar puncture (culture/microscopy, GeneXpert)
   - Imaging (MRI preferred)
4. Look hard for TB elsewhere
   - CXR +/- CT
   Sputum/BAL/gastric lavage

Question 3

1.What is the approach to rx for a patient HIV-assoc TB? 2. When should you commence ART in a patient with TB who has been found to be HIV positive

Answer 3

1. It is important to urgently commence active TB rx as this is the highest cause of mortality.
2. You would commence TB rx and ART should be commenced as soon as possible within 2 weeks. Can consider prophylaxis with steroids

Question 4

What are the three options for treatment of patients with TB and HIV infection

Answer 4

1. NRTI + NRTI + efavirenz and TB rx as usual (rifampicin does not react with efavirenz but does react with dolutegravir)
2. NRTI + NRTI + dolutegravir BD dosing
3. Rifabutin with a protease inhibitor?
   Rifamycin free TB rx?
   MDT? Assess risk benefit

Question 5

Treatment of TB-IRIS?

Answer 5

Symptomatic - eg drain abscess, NSAIDs
Don’t stop TB rx or ART
Severe cases: consider corticosteroids

Question 6

Treatment of drug-resistant TB?
1. H monoresistance:
2. R monoresistance:
3. RR/MDR:

Answer 6

1. H monoresistance = 6REZLfx
   - 6 mo of rifampicin, ethambutol, pyrazinamied and levofloxacin
2. R monoresistanxce = same as MDR
3. RR/MDR= 3 options:
   
   • BPaLM: 6 mo bedaquiline, pretomanid, linezolid and moxifloxacin
   • OR 9-12 mo all oral regimen which is not used as much
   • Longer regimens where you must use all 3 group A agents and at least one group B agent

Question 7

Why is diagnosis of TB in HIV + patients difficult?

Answer 7

• IGRA/mantoux test less reliable
• Atypical CXR findings
• Bronchial spread of bacilli less likely therefore AFB sputum = less yield

Question 8

Risk factors for TB-IRIS

Answer 8

• Low CD4 count
• Disseminated TB
• HIgh pre-ART viral load/rapid reductionin VL
• Short time between TB treatment + ART initiation

Question 9

In what cases of TB would you consider steroids?

Answer 9

In pericardial TB or TB meningitis. Would also consider in setting of TB-IRIS or for prophylaxis of TB-IRIS in high risk patients.

Question 10

When should you start ART in a patient with TB meningitis

Answer 10

ART should be delayed 4-8 weeks

Question 11

When should you give INH preventative therapy in adults

Answer 11

• In HIV patients at high risk for TB, and in high burden setting would give INH and in low burden setting would consider it

Question 12

What are the side effects of isoniazid

Answer 12

• Peripheral neuropathy therefore supplement with pyridoxine as deficiency is the cause
• Drug-induced hepatitis (LFTs would show a transaminitis). Stop dosing if >5 times normal upper limit of transaminases or if sx or if elevated bilirubin

(and cutaneous hypersensitivity as for all of them)

Question 13

What are the side effects of ethambutol

Answer 13

optic neuropathy (and cutaneous hypersensitivity)

Question 14

What are the side effects of pyrazinamide

Answer 14

• Itching and arthralgia due to increased serum uric acid
• Drug-induced hepatitis (transaminitis) - stop dosing if >5 times normal upper limit of transaminases or if sx or if elevated bilirubin