Drugs and Resistances
Tuberculosis
is a bacterial infection which is good because antibiotics are available to
fight TB.
TB Antibiotics have been around since 1944 when Streptomycin was
introduced and others subsequently followed, including:
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Isominazid-1952
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Rifampicin-1965
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Ethambutol-1968
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Pyrazinamide-1970
Most are used in conjunction with each other and can come in fixed doses that enable quick and effective treatment.
Drug resistant (DR) Tuberculosis is defined as a strain of Tuberculosis that is resistant to one of the "first line" drugs listed above.
When drug-resistance strains pop up many treatment options are suppressed and doctors are forced to use more dangerous second-line drugs.
The most prevalent resistance strains render Isomiazid and Rifampicin useless and Rifabutin will only work 30% of time if the strain is resistant to
Rifampicin because of molecular similarity.
Multi-Drug resistant (MDR) Tuberculosis is defined as a strain of Tuberculosis that is resistant to more than one first line drug.
As resistance emerges treatment costs increase to $15,000 per person/treatment which equates to 3000 times the cost of treating regular TB.
The duration also increases from 6-8 months to 18-24 months with MDR strains. In conjunction, the second line drugs can cause nasty side
effects such as depression, hepatitis, and hallucinations. The reason the cost increases so much is due to the inability to "buffer stock" the drugs
because most second line drugs have a short shelf life. 500,000 new cases of MDR Tuberculosis are document yearly.
The scariest DR Tuberculosis strains are the Extreme Drug Resistant (XDR) strains which are defined as strains resistant to three or more of
the six classes of second-line drugs. They are non-responsive to virtually all treatment options and achieve upwards of 95% mortality rates
with a very short gestation period. In Latvia 19% of all MDR-TB cases met the XDR-TB criteria and in a study, 52 of 53 patients studied
died within 25 days of being diagnosed.
AIDS and TB are a very lethal combination because as AIDS decreases the immune systems response, TB explodes. Of the 40 million people around the world
with AIDS 1/3 have TB. TB is the leading cause of death amongst AIDS victims with a 90% mortality rate amongst the untreated. TB also acts rather strangely in
AIDS victims undergoing migration more easily to places like the brain and spinal cord.
So what can we do? Unfortunately there is no market pressure to produce new medication due to third world countries being the most afflicted. TB is effectively
a poor man’s disease as they can’t afford the medication required to be cured.
In the coming years decrease the prevalence of TB worldwide include:
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Free screening to HIV positive people
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Free HIV tests to TB positive people
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New drugs with shorter treatment time
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Fixed combo doses for children