Trimethoprim-sulfamethoxazole TMP-SMX

Streptococcus gentamicin (5 mg/kg per day, dosing based on serum levels) Alternative Therapies Trimethoprim-sulfamethoxazole (TMP-SMX) 10-20 mg/kgTMP IV per day in divided doses every 6-8 hours or meropenem Standard Therapy TMP-SMX Rash, Stevens-Johnson syndrome, bone marrow suppression, nausea/vomiting, hepatotoxicity 14-21... 

CA-MRSA is susceptible to more antibiotics than HA-MRSA. Like HA-MRSA, CA-MRSA typically is sensitive to vancomycin, linezolid, daptomycin, tigecycline, and quinupristin/ dalfopristin, but it also may be sensitive to clindamycin, doxy-cycline, minocycline, and/or trimethoprim-sulfamethoxazole (TMP-SMX).14... 

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-sulfamethoxazole (TMP-SMX) was introduced as a fixed dose combination in 1968. Trimethoprim was added to sulfamethoxazole to synergisti-cally and sequentially inhibit bacterial synthesis of tetrahydrofolic acid. The combination was also designed to delay development of bacterial resistance. Sulfamethoxazole was selected in part because it is a congener of the frequently used sulhsoxazole but exhibits slower enteric absorption and urinary excretion. Sulfamethoxazole has a half-life similar to that of trimethoprim. 

The incidence of Pneumocystis carinii pneumonia (PCP) within the first year after transplantation is reported to be 3% to 5%. " Low-dose trimethoprim-sulfamethoxazole (TMP-SMX 400 mg/ 80 mg three times weekly) is effective in the prevention of PCP infections. Alternative agents include aerosolized pentamidine (300 mg every month), dapsone, and atovaquone. The duration of PCP prophylaxis is unclear. The risk of infection caused by P. carinii is likely to decrease as immunosuppression is reduced therefore, prophylaxis in patients requiring treatment for acute rejection may be appropriate. 

Oral Therapy Sulfonamides Trimethoprim-sulfamethoxazole (TMP-SMX) These agents generally have been replaced by more agents due to resistance. This combination is highly effective against most aerobic enteric bacteria except Pseudomonas aeruginosa. High urinary tract tissue levels and urine levels are achieved, which may be important in complicated infection treatment. Also effective as prophylaxis for recurrent infections. 

A family of antibiotics called sulfonamides, that stops the growth of bacteria, is used to treat UTI. These include trimethoprim-sulfamethoxazole (TMP-SMX) and cephalasporins. Aztreonam and fluoroquinolones are used as urinary tract antiseptics. Phenazopyridine (Pyridium) is used to treat pain from a UTI. 

Lee BL, Lampiris H, Colbom DC, Lewis RC, Narang PK, Sullam P The effect of rifabutin (RBT) on the pharmacokinetics (PK) of trimethoprim-sulfamethoxazole (TMP-SMX) in HIV-infected patients Intersci Ccmf Antimicrob Agents Chemoffier (1995) 35, 7... 

Trimethoprim-sulfamethoxazole (TMP-SMX) (20 mg/kg/day of trimethoprim) is the treatment of choice for P. carinii pneumonia (PCP). Oral therapy with TMP-SMX is reserved for children with mild PCP who do not have malabsorption or diarrhea. Intravenous pentamidine (4 mg/kg/day, given once a day) can be given to children with PCP who are intolerant of TMP-SMX or who have not responded after 5 days of TMP-SMX therapy. Other treatment regimens that may be considered for patients who are intolerant of or fail TMP-SMX and pentimidine are (1) atovaquone (40 mg/kg/ day, in two divided doses) for mild/moderate PCP only (2) dapsone with trimethoprim (3) trimetrexate with leucovorin and (4) clindamycin and primaquine. These alternate treatments have limited experience in pediatric patients. 

ACE-I, angiotensin-converting enzyme inhibitors ARB, angiotensin-receptor blockers AZA, azathioprine CMV, cytomegalovirus CPK, creatinine phos-phokinase CSA, cyclosporine HMG-CoA, 3-hydroxy 3-methylglutaryl coenzyme A reductase K+, potassium LFTs, liver function tests Rl, renal insufficiency SCr, serum creatinine SRL, sirolimus TAC, tacrolimus TMP-SMX, trimethoprim-sulfamethoxazole. 

BUN, blood urea nitrogen CBC, complete blood cell count CNS, central nervous system CYP, cytochrome P-450 isoenzyme LFT, liver function test MAO, monoamine oxidase QTc, Q-T interval corrected for heart rate SCr, serum creatinine TMP-SMX, trimethoprim-sulfamethoxazole. 

DS, double strength SS, single strength TMP, trimethoprim TMP-SMX, trimethoprim-sulfamethoxazole. °Dosing internals for normal renal function. 

Serious adverse effects are rare except in AIDS patients. TMP-SMX can cause the same adverse effects as those associated with sulfonamide administration, including skin rashes, central nervous system (CNS) disturbances, and blood dyscrasias. Blood dyscrasias, hepatotoxicity, and skin rashes are particularly common in patients with AIDS. Most of the adverse effects of this combination are due to the sulfamethoxazole component. Trimethoprim may increase the hematological toxicity of sulfamethoxazole. Long-term use of trimethoprim in persons with borderline foUc acid deficiency, such as alcoholics and the malnourished, may result in megaloblastic anemia, thrombocytopenia, and granulocytopenia. 

PCP = Pneumocystis carinii pneumonia AIDS = acquired immunodeficiency syndrome ADR adverse drug reaction TMP-SMX = trimethoprim sulfamethoxazole. 

TMP-SMX = trimethoprim-sulfamethoxazole CSA = cyclosporine TAC = tacrolimus ACEI = ACE inhibitor Rl = renal insufficiency CMV = cytomegalovirus SRL = sirolimus CPK = creatinine phosphokinase enzymes LFTs = liver function tests K+ = potassium Scr = serum creatinine HCT = hematocrit. 

Trimethoprim (TMP), a folate analog and inhibitor of dihydrofolate reductase (Figure V-1-3), is usually used together with sulfamethoxazole (SMX). The simultaneous inhibition of the tetrahydrofolate synthesis pathway at two steps has a synergistic effect and prevents the rapid generation of resistance. The clinical uses and side effects of TMP-SMX are discussed. 

Trimethoprim-sulfamethoxazole Protein-Binding 50-65% (TMP-SMX) Half-Life 8-12 hours Most widely used antibacterial agent in the world ... 

Table 3. Representative Minimum Inhibitory Concentrations for Urinary Tract Organisms by Sulfamethoxazole (SMX), Trimethoprim (TMP), and Their Combination...

Trimethoprim (TMP)-Sulfamethoxazole (SMX) [Co-Trimoxa-zole] (Bactrim, Septra) Vancomycin (Vancocin, Vancoled)... 

Alert All dosage forms have same 5 1 ratio of sulfamethoxazole (SMX) to trimethoprim (TMP). 

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