This is just an introduction to tuberculosis. We'll just put Tuberculosis I for the title.
I use the acronym RIPE as in the induration which shows a positive TB
test looks like the skin is ripe.
I'm going to change that a little bit to RIPE-R just so that we'll talk about another R
that is very important. The RIPE or RIPE-R acronym begins with rifampin, brand
Rifadin, though
worldwide
I see rifampicin as the drug name.
Isoniazid, which really comes generic only, the medical abbreviation is INH.
These words tend to get really long. Pyrazinamide, which is PZA, and then ethambutol,
which is brand Myambutol. So R - rifampin, I - isoniazid, P - pyrazinamide, E - ethambutol.
If you had a protease inhibitor substitution,
you would use a protease inhibitor
substitution for rifampin,
which would be rifabutin, brand Mycobutin, if the patient was HIV positive on a protease inhibitor.
Practice question one,
we're not going to do the classes because they're all anti-tubercular. Their mechanism of action isn't really as important in this.
'Generally, we use multiple medicines for TB treatment except for latent TB, when a nine-month course of blank might be appropriate?'
Select all that apply.
In this case it would be
isoniazid. It's really the staple of
the
four drugs that we would use initially for TB. If it's an active TB,
practice question two let's make A) correct: 'The TB medication that can cause body fluids including urine to turn red-orange?'
That's rifampin. Use the R for red as a way to remember it. The saliva, the sweat, the tears
can also become red orange as well.
Question three:
'This TB medication is a metabolic inducer making some medicines less effective?' Just to remind you, a metabolic inducer is
the opposite of a metabolic inhibitor, so a metabolic inhibitor
stops or slows the
metabolism of a drug. When you slow the metabolism or the change into
metabolites, then you get more of the drug around.
An inducer will do the opposite in which if you induce the metabolism,
you actually speed it up and whatever interaction it has, there's going to be less of it around. Rifampin
has this interaction with warfarin,
oral contraceptives, and protease inhibitors, and
that would mean that you have less warfarin,
so instead of the patient bleeding, it would actually cause the patient to be under-coagulated
if that's a word where they might have a stroke or they might have
Some kind of thrombotic event because the coagulation is not proper.
The oral contraceptives, if you have less oral contraceptive might result in pregnancy, and the protease inhibitors,
it would cause them to not work as well, and then that would allow the HIV to remain.
Rifampin would be
the one that causes this metabolic induction.
'This TB medication would be replaced by rifabutin in an HIV-positive patient on a protease inhibitor?'
Rifampin again, because of that metabolic induction. Now we would replace it with rifabutin. It's related but not quite the same.
Question five: 'This TB medication can cause peripheral neuropathy?'
Isoniazid, which is a staple, can cause peripheral neuropathy. It is a weakness
that
the nerves cause, so somebody buttoning a shirt might really struggle with it because they really can't feel
that tactile sensation that they normally do. Think of the isoniazid, it's 'N' for neuropathy to remember that.
Number six: 'This TB medication may necessitate treatment with a ibuprofen for joint pain?'
A side effect of pyrazinamide in almost half of patients that get it is
something called polyarthralgia.
Many from poly- and then -arthralgia is
joint pain, so many joint pain or pain in many joints.
Use the 'P' in pyrazinamides to help you remember polyarthralgia.
Question seven: 'This TB medication may cause optic neuritis?'
Ethambutol
is
known for this and you can take the 'E' for eyes or the 'o' from optic to remember optic neuritis from ethambutol.
Question eight: 'Most first-line TB medications cause hepatotoxicity, which is the exception?'
Rifampin, isoniazid and pyrazinamide, they all are hepatotoxic, all damage the liver.
When there are patients on all these medicines, we really need to watch liver function tests.
Ethambutol doesn't have that hepatotoxicity as the side effect. It's the one exception.
Question nine:
'In the first two months of TB treatment of an HIV negative patient, we expect
which medications in the regimen?' We would actually expect all four - rifampin, isoniazid,
pyrazinamide and ethambutol for quad therapy.
Practice question ten: 'In the next four months of TB treatment, that kind of continuation
phase, of an HIV negative patient, we expect which medications in the regimen?' It would be rifampin and isoniazid.