Trimethoprim, consider

Repeat every 28 days to maximal response plus 2 cycles Consider prophylaxis with trimethoprim-sulfanethoxazole... 

Consider prophylaxis with trimethoprim-sulfanethoxazole Rituximab 375 mg/M2 IV days 1,8,15,22... 

The answer is d. (Hardman, p 989.) Both trimethoprim-sulfamethoxazole and pentamidine are effective in pneumonia caused by E carinii. This protozoal disease usually occurs in immunodeficient patients, such as those with AIDS. Nifurtimox is effective in trypanosomiasis and metronidazole in amebiasis and leishmaniasis, as well as in anaerobic bacterial infections. Penicillins are not considered drugs of choice for this particular disease state. 

Cephalexin is considered safe and effective. Nitrofurantoin should not be used after week 37 due to concern for hemolytic anemia in the newborn. Sulfa-containing drugs may increase risk for kernicterus in the newborn and should be avoided during the last weeks of gestation. Folate antagonists, such as trimethoprim, are relatively contraindicated during the first trimester because of their association with cardiovascular malformations. Fluoroquinolones and tetracyclines are contraindicated. 

Initial therapy with trimethoprim-sulfamethoxazole appears to be effective for CA-MRSA and should be considered in geographic areas in which CA-MRSA are commonly encountered. Alternative agents for documented infections with resistant gram-positive bacteria such as methicil-lin-resistant staphylococci and vancomycin-resistant enterococci include linezolid, quinupristin/dalfopristin, daptomycin, and tigecycline. 

Tetracycline or trimethoprim-sulfamethoxazole and fluoroquinolones are recommended as alternatives for infections caused by P. multocida or those allergic to penicillins (but not in children or pregnant women). Erythromycin may be considered an alternative in growing children or pregnant women. 

The recommended treatment is doxycycline (200 mg/day) plus rifampin (600 mg/day) for six weeks. An alternative effective treatment is six weeks of doxycycline (200 mg/day) plus streptomycin (1 gm/day) for three weeks. Trimethoprim-sulfamethoxazole given four to six weeks is less effective. In 5 to f 0 percent of cases, there may be a relapse or treatment failure. Regarding prophylaxis, killed and live attenuated human vaccines are available in many countries but are considered of unproven efficacy. There tends to be no information on the use of antibiotics for prophylaxis against human brucellosis. 

Tetracycline 500 mg every six hours or doxycycline 100 mg every twelve hours for five to seven days will shorten the duration of illness, and fever usually disappears within one to two days after treatment is begun. Ciprofloxacin and other quinolones are active in vitro and should be considered for victims unable to take tetracycline or doxycycline. Successful treatment of Q fever endocarditis is much more difficult. Tetracycline or doxycycline given in combination with trimethoprim-sulfamethoxazole (TMP-SMX) or rifampin for twelve months or longer has been successful in some cases. However, valve replacement is often required to achieve a cure. 

Trimethoprim is a diaminopyrimidine derivative. It is reasonably basic (p/fa 7.2) and we should remember here that amino substituents are able to utilize their lone pairs and provide resonance stabilization to a conjugate acid. Consequently, aminopyrimidines protonate on a ring nitrogen. If we consider protonation of the two ring nitrogens separately, and then think about potential resonance stabilization, we can predict the site of protonation. 

Trimethoprim exhibits broad-spectrum activity. It is most commonly used in combination with sulfamethoxazole and is active against most gram-positive and gramnegative organisms, especially the Enterobacteriaceae. There is little activity against anaerobic bacteria P. aeruginosa, enterococci, and methiciUin-resistant staphylococci should be considered resistant to trimethoprim. 

A combination of trimethoprim-sulfamethoxazole is effective treatment for a wide variety of infections including P jiroveci pneumonia, shigellosis, systemic salmonella infections, urinary tract infections, prostatitis, and some nontuberculous mycobacterial infections. It is active against most Staphylococcus aureus strains, both methicillin-susceptible and methicillin-resistant, and against respiratory tract pathogens such as the pneumococcus, Haemophilus sp, Moraxella catarrhalis, and Klebsiella pneumoniae (but not Mycoplasma pneumoniae). However, the increasing prevalence of strains of E coli (up to 30% or more) and pneumococci that are resistant to trimethoprim-sulfamethoxazole must be considered before using this combination for empirical therapy of upper urinary tract infections or pneumonia. 

On the other hand, the volume of disfiibution is significantly increased for orally administered trimethoprim in feverish rabbits compared with their healthy counterparts and absorption is reduced (38). The significance of these changes can be appreciated if one considers that the total body clearance of a drug is... 

In chronic bronchitis, suppressive chemotherapy, generally needed only during the colder months (in temperate, colder regions), may be considered for patients with symptoms of pulmonary insufficiency, recurrent acute exacerbations or permanently purulent sputum. Amoxicillin or trimethoprim is suitable for treatment. 

It is important to consider the influence of interaction between functional groups of drugs that leads to their habit modification when formulated in suspension dosage form. Proton transfer from the N atom of sulfamethoxazole to the pyrimidine basic N1 atom of trimethoprim has been reported to occur in their equimolar complexes. Bettinetti et al. have reported nucleation of the complex of trimethoprim and sulfa-methoxypyridazine (1 1) to be accelerated by water or wet granulation. Our studies on cotrimoxazole (unpublished results) revealed immediate formation of fine needle-shaped crystals irrespective of the initial shape of sulfamethoxazole and trimethoprim crystals as a result of the interaction between the two drugs in suspension form. Small needles (Fig. 6A) were... 

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