Legionella infection, treatment

It Is easier to demonstrate synergy in vitro than in vivo, and concerns about the toxic contribution of the sulfonamide (and, doubtless, commercial considerations as well) have led to a recent vogue for the use of trimethoprim alone. Trimethoprim has a broad spectrum in vitro, so it Is potentially useful against many microorganisms. Combined with sulfamethoxazole, it Is used for oral treatment of urinary tract infections, shigellosis, otitis media, traveler s diarrhea, methicillin-resistant Staphylococcus aureus (MRSA), Legionella infection, and bronchitis. 

It is indicated in the treatment of lower respiratory tract infection e.g. bronchitis and pneumonia, upper respiratory tract infections e.g. pharyngitis and sinusitis, infections due to chlamydia, legionella and mycoplasma, skin and soft tissue infections and eradication of H. pylori with acid suppressants. 

Levofloxacin, gatifloxacin, gemifloxacin, and moxifloxacin, so-called respiratory fluoroquinolones, with their enhanced gram-positive activity and activity against atypical pneumonia agents (eg, chlamydia, mycoplasma, and legionella), are effective and used increasingly for treatment of upper and lower respiratory tract infections. 

Treatment should continue for 10 days for a severe infection and longer for certain pathogens such as Staphylococcus aureus and Legionella pneumophila. 

Clarithromycin is indicated for the treatment of mild to moderate upper and lower respiratory tract infections as well as skin infections caused by susceptible strains of Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, H. influenzae, Legionella pneumophila, and Mycoplasma pneumoniae. The usual dosage is 250 to 500 mg twice a day for 7 to 14 days. 

There is accumulating data that alterations in cytokine expression play a critical role in enhanced mortality and morbidity in experimental animals. Klein et al. (1993) reported that THC induced cytokine-mediated mortality of mice infected with L. pneumophila. Mice administered two injections of THC, one before and one after a sublethal dose of Legionella experienced acute collapse and death. The THC-induced mortahty resembled cytokine-mediated shock, and acute-phase serum from these animals contained significantly elevated levels of TNF and IL-6. The investigators concluded that THC increased the blood levels of acute-phase cytokines in the infected animals and that these elevated levels, at least in part, accounted for mortalities induced by THC. Newton et al. (1994) demonstrated that drug treatment of mice suppressed Thi anti-Legionella immu-... 

Klein TW, Newton CA, Nakachi N, Friedman H (2000) Delta-9-tetrahydrocannabinol treatment suppresses immunity and early IFN-gamma, lL-12, and IL-12 receptor beta 2 responses to Legionella pneumophila infection. J Immunol 164 6461-6466... 

C. Clinical Uses Erythromycin is effective in the treatment of infections caused by Mycoplasma pneumoniae, corynebacterium. Chlamydia trachomatis, Legionella pneumophila, Ureaplasma urealyticum, and Bordetella pertussis. The drug is also active against gram-positive cocci, including pneumococci and beta-lactamase-producing staphylococci (but not MRSA strains). 

Kutzman I, Soldo I, Schonwald S, Culig J. Azithromycin for treatment of community acquired pneumonia caused by Legionella pneumophila a retrospective study. Scand J Infect Dis 1995 27 503-505. 

---