Rifamycins are bactericidal and suppress the RNA synthesis by inhibiting the DNA-dependent RNA polymerase (see Table: rifamycins). Rifamycins rifampicin rifabutin rifaximin rifapentine rifampin, rifabutin and rifapentine rifampin, rifabutin and rifapentine have similar pharmacological properties, antimicrobial activity spectra and unwanted effects. Pharmacology The absorption after oral administration is good and leads to a broad distribution in body tissues and fluids, including cerebrospinal fluid. Rifampicin accumulates in polymorphonuclear granulocytes and macrophages, which facilitates the elimination of bacteria from abscesses. It is metabolized in the liver and biliary and to a much smaller Notes as the urine eliminiert.Indikationen Rifampicinwirkt against most gram positive and some gram negative bacteria Mycobacterium sp. Due to rapid development of resistance rifampicin is rarely used as a single agent. Rifampicin is used with other antibiotics for TB (tuberculosis (TB): first-line drugs) Atypical mycobacteria (rifampicin is effective against many non-tuberculous mycobacteria, but rapidly growing mycobacteria such as Mycobacterium fortuitum, M. chelonae or M. abscessus are of Nature (from resistant) leprosy with dapsone with or without clofazimine) staphylococcal infections, including osteomyelitis, Klappenprothesenendokarditis and infection with foreign bodies such. As a prosthetic joint infection (in other staphylococcal antibiotics) Legionella infections (older data point to better results for rifampicin out when used with erythromycin; the use of rifampicin with azithromycin or a fluoroquinolone offers no advantage) pneumococcal meningitis when organisms susceptible to rifampicin are (with vancomycin with or without ceftriaxone or cefotaxime with ceftriaxone or cefotaxime-resistant pathogens [MIC> 4 ug / ml]), or if clinical or microbiological delayed reaction is expected. Rifampicin can be used as a single agent for the prophylaxis following close contact with patients with meningococcal or haemophilus influenzae type b meningitis. Rifabutin and rifampin are equally effective for TB treatments in HIV-positive and HIV-negative patients. Rifabutin is more effective than rifampicin against M. avium complex, and is preferably used in these infections as part of a combination therapy, but otherwise Rifampin is preferred. Rifapentine is used to pulmonary TB and latent TB to behandeln.Kontraindikationen rifampin and rifabutin are in patients who have had an allergic reaction to this, kontraindiziert.Anwendung during pregnancy and lactation rifabutin is in pregnancy category B (animal studies show no risk and experience humans are incomplete or animal studies show risk, but human studies do not). Safety during breast-feeding is not known. Rifampicin and rifapentine are in Pregnancy Category C (animal studies show some risk [in this case, teratogenicity], evidence in human studies are insufficient, but sometimes the clinical benefit outweighs the risk). The drug crosses the placenta. Nevertheless, when risk of TB in the mother is moderate or high, the treatment considered less harmful to the fetus than an untreated TB of the mother and is therefore recommended. Because of the potential tumorigenicity, which was found in animal studies, the manufacturer does not recommend the use of rifampicin during lactation. However, the Centers for Disease Control and Prevention (CDC) rifampin seen not as a contraindication to breastfeeding; a decision to either stop breast-feeding or taking the drug should be made depending on the importance of the drug to the mother ist.Nebenwirkungen Among the side effects hepatitis (severe) GI disorders CNS effects myelosuppression hepatitis occurs more frequently when isoniazid or pyrazinamide is concurrently administered with rifampicin. During the first week of therapy rifampicin can lead to a temporary increase of unconjugated serum bilirubin due to competition from Rifambicin and bilirubin to excretion, which in itself is not an indication for the interruption of treatment. Among the CNS effects headache, dizziness, ataxia and confusion may belong. Rash, fever, leukopenia, anemia, thrombocytopenia, interstitial nephritis, acute tubular necrosis, renal failure and interstitial nephritis are generally considered hypersensitivity reactions and occur when the treatment is interrupted or if the treatment after an interruption is resumed from a once-daily dosing application ; these are reversible if the intake of rifampicin is stopped. Less serious side effects are common; these include heartburn, nausea, vomiting and diarrhea. Rifampicin colored urine, saliva, sweat, sputum and tears orange.Überlegungenzur dosage If patients have liver disease, should prior to treatment with Rifambicin and during treatment every 2-4 weeks liver function tests performed or an alternative drug to be used. Dosage adjustment in renal impairment is not required. Rifampin has on interactions with many drugs, because it is a potent inducer of the hepatic microsomal enzyme cytochrome P-450 (CYP 450). Rifampicin accelerates the precipitation and can reduce the effectiveness of the following drugs: ACE inhibitors, atovaquone, barbiturates, ?-blockers, calcium channel blocker, chloramphenicol, clarithromycin, oral and systemic hormonal contraceptives, corticosteroids, cyclosporin, dapsone, digoxin, doxycycline, fluconazole, haloperidol, itraconazole, ketoconazole, the non-nucleoside reverse transcriptase inhibitors delavirdine and nevirapine, opioid analgesics, phenytoin, protease inhibitors, quinidine, sulfonylureas, tacrolimus, theophylline, thyroxine, tocainide, tricyclic antidepressants, voriconazole, warfarin, and zidovudine. To obtain an optimal therapeutic effect of these drugs, doctors need to adjust the dosage if the treatment begins with rifampicin or stopped eventually. Conversely inhibit protease inhibitors, as well as other drugs (eg. B. azoles, the macrolide is clarithromycin, non-nucleoside reverse transcriptase inhibitors) CYP450 enzymes and increase the levels of the rifamycins and thus possibly the frequency of toxic reactions. For example, frequently occurs uveitis when rifabutin is administered with clarithromycin or azoles. Rifaximin Rifaximin is a derivative of rifamycin that is poorly absorbed after oral administration; 97% is excreted unchanged in the chair. Rifaximin may be administered to the empirical treatment of traveler’s diarrhea, which is caused primarily by enterotoxigenic and enteroaggregative Escherichia coli. It is not known whether rifaximin even with diarrhea due to pathogens other than E. coli. acts. Because Rifaximin is not absorbed systemically, it should not be used to treat infectious diarrhea caused by invasive enteric bacterial pathogens (eg. As Salmonella, Campylobacter sp) were caused. The dose is 200 mg p.o. every 8 hours for 3 days in adults and children> 12 years. Adverse effects are for. As nausea, vomiting, abdominal pain and bloating.