TB

Question 1

There are two TB regimens recommended for the treatment of tuberculosis in the UK. What are these and can they be used at the same time?

Answer 1

1) unsupervised regimen or the supervised regimen

2) the two regimens should not be used concurrently

Question 2

outline the treatment of TB during the initial phase, including which drugs are involved

Answer 2

1) Rapidly reduce population of mycobacterium tuberculosis - to minimise resistance
2) 4 drugs: Isoniazid, rifampicin, pyrazinamide, ethambutol used daily ( Rifater) with pyridoxine
3) Last for 2 months. Treatment should be started without waiting for culture results and continued even if initial culture results are negative

Question 3

what is the purpose of pyridoxine hydrochloride?

Answer 3

prophylaxis of isoniazid-induced neuropathy

Question 4

outline the treatment of TB during the continuation phase, including which drugs are involved

Answer 4

1) After initial phase, OD treatment is continued for 4 months
2) 2 drugs : Rifampicin and isoniazid (preferably combination - Rifinah) with pyridoxine

Question 5

who is the unsupervised treatment suitable for?

Answer 5

1) patients who are likely to take antituberculosis drugs reliably without supervision.
2) The standard unsupervised six month treatment regimen may be used during pregnancy and is fine in BF

Question 6

Drug administration should be fully supervised (directly observed therapy, DOT) in patients who cannot comply reliably with the treatment regimen. if this is not possible what option is available?

Answer 6

1) a supervised dosing schedule of three times a week should be considered.
2) Regimens with a dosing schedule of fewer than three times a week should not be used.

Question 7

Directly observed therapy should be offered to patients which patients?

Answer 7

1) history of non-adherence
2) previously been treated for tuberculosis
3) denial of the tuberculosis diagnosis
4) have multidrug-resistant tuberculosis
5) psychiatric or cognitive disorder
6) Homelessness, drug or alcohol misuse;
7) are in prison, or have been in the past 5 years
8) are too ill to self-administer treatment
9) request directly observed therapy

Question 8

how does treatment for TB differ if there is Central nervous system involvement?

Answer 8

1) initial 2 month phase same, continuation with rifampicin and isoniazid (+pyridoxine) for 10 months
2) high dose of dexamethasone or prednisolone started at the same time and then withdrawn over 4–8 weeks

Question 9

how should close contacts be managed with TB?

Answer 9

1) Aged under 65 years who is a close contact (prolonged e.g. partners) of a person with pulmonary or TB should be tested for latent tuberculosis
2) Chemoprophylaxis offered to all patients aged < 65 years, with evidence of latent tuberculosis if the close contact has suspected/confirmed-active TB

Question 10

should health care workers from a TB country be tested?

Answer 10

new entrants from a high incidence country should be offered appropriate testing for latent tuberculosis if BCG vaccination cannot be verified

Question 11

how should latent TB be treated?

Answer 11

1) Either isoniazid (+pyridoxine ) alone for six months

2) or rifampicin and isoniazid (+ pyridoxine hydrochloride) for three months

Question 12

how should Treatment failure for TB be managed?

Answer 12

1) Major causes of failure are incorrect prescribing or inadequate compliance by the patient
2) Monthly tablet counts and urine examination (rifampicin imparts an orange-red coloration) may be useful indicators of compliance with treatment..

Question 13

what is classified as treatment interruption in in TB therapy?

Answer 13

1) A break in antituberculosis treatment of at least two weeks (during the initial phase) or missing more than 20 % of prescribed doses is classified as treatment interruption

Question 14

During the first two months (‘initial phase’) of rifampicin administration what hepatic changes might occur?

Answer 14

1) transient disturbance of liver function with elevated serum transaminases is common but generally does not require interruption of treatment.
2) Occasionally more serious liver toxicity requires a change of treatment particularly in those with pre-existing liver disease.

Question 15

On intermittent treatment six toxicity syndromes have been recognised and can occur in 20–30% of patients. list these

Answer 15

1) Influenza-like
2) Abdominal
3) Respiratory symptoms
4) Shock
5) Renal failure
6) Thrombocytopenic purpura

Question 16

what is the treatment for TB in children?

Answer 16

treatment is the same for children. But care is needed in young children receiving ethambutol because of the difficulty in testing eyesight and in obtaining reports of visual symptoms.

Question 17

what should be monitored during TB treatment?

Answer 17

1) Drug levels
2) FBC
3) Urinalysis
4) Hepatic
5) Renal
6) Vision
7) Hearing in elderly

Question 18

what patient and carer advice should be given to patients taking rifampicin?

Answer 18

1) discolor contact lenses, urine colour orange
3) side effects include the six toxicity syndromes , may occur with intermittent therapy
3) Told how to recognise signs of liver disorder e.g. symptoms such as persistent nausea, vomiting, malaise or jaundice develop.

Question 19

what are the monitoring requirements for rifampicin?

Answer 19

1) Renal function, Hepatic function before treatment
2) Hepatic : Further checks only necessary if the patient develops fever, malaise, vomiting, jaundice or unexplained deterioration during treatment.
2) Blood counts and liver functions should be monitored with prolonged therapy

Question 20

what side effect can ethambutal cause ?

• other SE include: Hyperuricaemia; nerve disorders; visual impairment

Answer 20

1) Ocular toxicity common with excessive dosage or renal function impaired (avoid if severe). Early discontinuation of the drug is almost always followed by recovery of eyesight.
2) Visual acuity should be tested by Snellen chart before treatment with ethambutol.

Question 21

what patient and carer advice should be given to those taking ethanmbutol?

Answer 21

ocular toxicity - discontinue therapy immediately if they develop deterioration in vision and promptly seek further advice.

Question 22

who should isoniazid be used in caution with?

Answer 22

1) Drug-induced liver disease
2) diabetes mellitus
3) epilepsy
4) Acute porphyrias

Question 23

what side effect is isoniazid known for causing and how is this managed?

Answer 23

1) Peripheral neuropathy - higher risk in diabetes, alcohol dependence, chronic renal failure, pregnancy, malnutrition
2) In patients at increased risk of peripheral neuropathy, pyridoxine given

Question 24

what are the main side effects of isoniazid?

Answer 24

1) Hepatitis more common in those aged over 35 years and those with a daily alcohol intake
2) in renal impairment risk of ototoxicity and peripheral neuropathy

Question 25

what patient and carer advice should be given to those taking isoniazid?

Answer 25

1) Avoid tyramine-rich foods

2) Told how to recognise signs of liver disorder

Question 26

summarise the side effects caused by TB treatment

Answer 26

1) Isoniazid - peripheral neuropathy
2) Ethambutol - ocular toxicity
3) Rifampicin - orange/red urine, contact lenses
4) pyrazinamide, Isoniazid, Rifampicin - liver toxicity