antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
used to treat
tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...
rifampin
Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), ''Mycobacterium avium'' complex, leprosy, and Legionnaires’ disease. It is almost always used tog ...
such as people with
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
on
antiretrovirals
The management of HIV/AIDS normally includes the use of multiple antiretroviral drugs as a strategy to control HIV infection. There are several classes of antiretroviral agents that act on different stages of the HIV life-cycle. The use of multipl ...
. For active tuberculosis it is used with other antimycobacterial medications. For latent tuberculosis it may be used by itself when the exposure was with
drug-resistant TB
Multidrug-resistant tuberculosis (MDR-TB) is a form of tuberculosis (TB) infection caused by bacteria that are resistant to treatment with at least two of the most powerful first-line anti-TB medications (drugs): isoniazid and rifampin. Some f ...
.
Common side effects include
abdominal pain
Abdominal pain, also known as a stomach ache, is a symptom
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than ...
,
nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
, rash,
headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Headaches can occur as a result ...
uveitis
Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and ...
. , especially when hitting Bartonella and Babesia colonies in the capillaries of the ciliary body in the eye anterior chamber. While no harms have been found during
pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ca ...
it has not been well studied in this population. Rifabutin is in the
rifamycin
The rifamycins are a group of antibiotics that are synthesized either naturally by the bacterium ''Amycolatopsis rifamycinica'' or artificially. They are a subclass of the larger family of ansamycins. Rifamycins are particularly effective again ...
family of medications. It works by blocking
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
production in bacteria.
Rifabutin was approved for medical use in the United States in 1992. It is on the
World Health Organization's List of Essential Medicines
The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health ...
.
Medical uses
Rifabutin is now recommended as first-line treatment for
tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...
(TB), but
rifampicin
Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), mycobacterium avium complex, ''Mycobacterium avium'' complex, leprosy, and Legionnaires’ disease. ...
was used more widely because of its cheaper cost. However, due to the expiration of patents, prices are now similar.
Rifabutin is also used in the treatment of ''Mycobacterium avium'' complex disease, a bacterial infection most commonly encountered in people with late-stage
AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...
. Its has fewer drug interactions than rifampicin, therefore people with HIV/AIDS on
HAART
The management of HIV/AIDS normally includes the use of multiple antiretroviral drugs as a strategy to control HIV infection. There are several classes of antiretroviral agents that act on different stages of the HIV life-cycle. The use of multiple ...
are typically prescribed rifabutin instead of rifampicin for the treatment of TB.
Rifabutin is well-tolerated in people with HIV-related TB, but new findings suggest that those with low CD4+ cell counts have a higher risk of treatment failure or relapse due to acquired rifamycin resistance. Since patients co-infected with TB and HIV are likely to be treated for TB first, when the CD4+ cell population is depressed at the time TB treatment begins, doctors and patients should be aware of the possibility for rifamycin resistance to develop.
Chron's disease
Rifabutin is being tested in clinical trials for treating
Crohn's disease
Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension ...
as part of the anti-
MAP
A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.
Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although ...
therapy. In a Phase III study administering sub-therapeutic doses of rifabutin in combination therapy to patients not identified with ''Mycobacterium avium'' ''paratuberculosis'' (MAP) infections, it was associated with significant short term benefits.
Others
Rifabutin is also being investigated for the treatment of infections caused by the Gram-negative bacillus ''
Acinetobacter baumannii
''Acinetobacter baumannii'' is a typically short, almost round, rod-shaped ( coccobacillus) Gram-negative bacterium. It is named after the bacteriologist Paul Baumann. It can be an opportunistic pathogen in humans, affecting people with compromi ...
'', which has shown promise in animal studies.
Rifamycins, including rifabutin, are useful in the treatment of ''
Chlamydophila pneumoniae
''Chlamydia pneumoniae'' is a species of ''Chlamydia (genus), Chlamydia'', an Obligate intracellular parasite, obligate intracellular bacterium that infects humans and is a major cause of pneumonia. It was known as the Taiwan acute respiratory ag ...
'' (Cpn) infection.
History
Scientists at the Italian drug company Achifar discovered rifabutin in 1975. (Eventually Archifar became part of
Farmitalia
Farmitalia was an Italian pharmaceutical company best known for its parallel discovery with Rhone-Poulenc of daunorubicin and subsequent discovery of doxorubicin.
Farmitalia had been founded in 1935 as a joint venture by Rhone-Poulenc and Monte ...
Carlo Erba, a unit of the conglomerate Montedison which was subsequently bought by
Pharmacia
Pharmacia was a pharmaceutical and biotechnological company in Sweden that merged with the American pharmaceutical company Upjohn in 1995.
History
Pharmacia company was founded in 1911 in Stockholm, Sweden by pharmacist Gustav Felix Grönfeldt ...
) This company's Adria Laboratories subsidiary filed for
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
(FDA) approval of rifabutin under the brand name Mycobutin in the early 1990s and the drug gained FDA approval in December 1992.
Rifabutin is primarily bactericidal antibiotic drug used to treat tuberculosis. Its effect on bacteria is based on the DNA-dependent RNA polymerase blocking drug rifamycin S, a semi-synthetic derivative. It is effective, for example, in highly resistant mycobacteria, Gram-positive bacteria (and some are effective against Gram-negative bacteria), but also against ''
Mycobacterium tuberculosis
''Mycobacterium tuberculosis'' (M. tb) is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' has an unusual, waxy coating on its c ...
'', ''M. leprae'', and ''M. avium intracellulare''.