Ethambutol
- 74-55-5 ( free base )
- 1070-11-7 ( dihydrochloride)
J04AK02
Antibiotic
- Free Base: 87.5 to 88.8 ° C
- Dihydrochloride: 198.5 to 200.3 ° C
Risk
240 mg · kg -1 ( LD50, mouse, i.v.)
Template: Infobox chemical / molecular formula search available
Ethambutol is a drug from the group of antibiotics, which is preferably used to treat tuberculosis, but also in other caused by mycobacteria infections. He may only be used in combination with other antimycobacterial agents. Due to the significant side effect profile, its use should be closely - are monitored - especially ophthalmologist.
Operation
Ethambutol is rapidly taken up by mycobacteria. It interferes with the normal structure of the cell walls due to their special structure in mycobacteria whose exceptionally high resistance caused by the biosynthesis of specific polysaccharides, known as arabinogalactans, Arabinomannane and peptidoglycans, is prohibited. This is due to an inhibitory effect on a path of the carbohydrate metabolism, the results of the glucose towards the arabinose and mannose.
It acts depends on the concentration bacteriostatic to bactericidal only to just proliferating ( proliferating ) pathogens. A primary resistance of mycobacteria to ethambutol is rare and acquired only develop slowly. There is no cross-resistance to other TB agents.
Pharmacokinetics
Ethambutol is absorbed rapidly and almost completely after taking from the gastrointestinal tract ( absorption ~ 80%). The highest concentration in the blood ( peak concentration ) is reached approximately 2-4 hours after ingestion. Excretion is primarily unchanged via the kidneys. Only a small proportion is excreted unchanged via the bile or in modified form in the urine. After 24 hours the concentration in the blood decreases less than one tenth of the peak level. Both red blood cells (erythrocytes ) and the tissue cells in the lung ( alveolar macrophages ) can accumulate ethambutol, so that the concentration in the cells is significantly higher than in serum.
Side effects
Depending on the dose administered and the duration of treatment there may be an inflammation of the optic nerve ( optic neuritis ) may occur, which later manifests itself initially by disturbance of color vision in visual field loss to complete loss of vision. Also, damage to both the central as well as peripheral nervous system ( neuropathy) with dizziness, headache, confusion states, hallucinations, weakness and numbness ( paresthesia ) are described. Common side effects include a rise in uric acid concentration in the serum, which returns to normal after discontinuation. Rarely, loss of appetite, heartburn, vomiting, diarrhea or allergic reactions with fever, or itchy rashes. Very rarely, changes in the blood picture with reduction in the number of white blood cells (leukocytes) or platelets (thrombocytes), and liver and kidney dysfunction can be observed.
Stereoisomerism
2 - [2 - (1- hydroxybutan -2- ylamino) ethylamino] butan- 1-ol contains two stereogenic centers, which are therefore provided with the same substituents, there is of the substance to three stereoisomers namely the ( S, S) - form, to mirror image (enantiomers ) (R, R)-form and the meso form. Only the (S, S ) is used as a drug form.
Trade names
EMF Fatol (D), Etibi (A) Myambutol (D, A, CH)
Rimstar (CH)