Tuberculosis flashcards
13 high-yield MRCP Part 1 cards from the Intellect Medicos Respiratory Medicine course. Try to answer each question before you open it — then study them properly with spaced repetition, which brings each card back just before you would forget it.
Study these 13 cards Save progress — free account
-
What is the standard treatment regimen for fully sensitive pulmonary TB?
Show answer
2 months of rifampicin, isoniazid, pyrazinamide and ethambutol (2HRZE), then 4 months of rifampicin and isoniazid (4HR).
Why? Four drugs in the intensive phase prevent resistance; the continuation phase sterilises remaining bacilli. Total 6 months.
-
How does treatment of TB meningitis (CNS TB) differ from pulmonary TB?
Show answer
Total 12 months (2HRZE + 10HR), plus adjunctive dexamethasone (or prednisolone) weaned over several weeks.
Why? Steroids reduce inflammation, death and neurological damage in TB meningitis.
-
What are the treatment options for latent TB infection (course notes)?
Show answer
3 months of rifampicin plus isoniazid (3RH), or 6 months of isoniazid alone (6H).
Why? Latent TB is asymptomatic and not infectious, but treatment prevents later reactivation.
-
Which vitamin is given with isoniazid, and why?
Show answer
Pyridoxine (vitamin B6), to prevent peripheral neuropathy.
Why? Isoniazid causes B6 deficiency; the risk is higher in diabetes, alcohol misuse, CKD, HIV, malnutrition and slow acetylators.
-
Name two important adverse effects or interactions of rifampicin.
Show answer
Any two of: orange-red body fluids (urine, tears — stains contact lenses); hepatitis; potent liver enzyme induction (e.g. makes hormonal contraception, warfarin and DOACs less effective).
Why? As a strong CYP450 inducer, rifampicin lowers levels of many drugs, so a full medication review is needed.
-
Which TB drug commonly causes hyperuricaemia and gout?
Show answer
Pyrazinamide.
Why? It reduces renal urate excretion. Pyrazinamide is also hepatotoxic.
-
Which TB drug causes optic neuritis, and what should be checked before starting it?
Show answer
Ethambutol; check visual acuity and red–green colour vision at baseline.
Why? Early signs are reduced acuity and red–green colour blindness. The dose is reduced in renal impairment.
-
What is the gold-standard investigation for pulmonary TB?
Show answer
Sputum mycobacterial culture (usually 3 samples, including an early-morning sample).
Why? Culture confirms the diagnosis and gives drug sensitivities. Smear microscopy (acid-fast bacilli) and NAAT/PCR give faster results.
-
Which tests detect LATENT TB infection?
Show answer
Interferon-gamma release assay (IGRA) or Mantoux tuberculin skin test.
Why? Both show immune sensitisation, not active disease; active TB must first be excluded (symptoms, CXR).
-
What is the Ghon complex in primary TB?
Show answer
A subpleural lung lesion (Ghon focus) plus enlarged hilar lymph nodes.
Why? Primary infection is often silent and heals, but bacilli may stay dormant and reactivate later.
-
Why does reactivation (post-primary) TB favour the upper lobes?
Show answer
The upper lobes have the highest oxygen tension, which suits the obligate aerobe M. tuberculosis.
Why? Reactivation TB causes upper-lobe cavitation with cough, haemoptysis, fever, night sweats and weight loss.
-
What are the typical CSF findings in TB meningitis?
Show answer
Lymphocytic pleocytosis, high protein and low glucose.
Why? Onset is subacute; cranial nerve palsies (especially VI) and hydrocephalus are classic complications.
-
Which part of the spine is typically affected in Pott's disease, and what are its key features?
Show answer
Thoracic and lumbar vertebrae: vertebral body destruction, disc-space narrowing, paravertebral (psoas) abscess and gibbus deformity.
Why? Cord compression can cause neurological deficit.