Sulfamethoxazole and trimethoprim

We proposed using MLC for assay of azithromycin in tablets and capsules. As alternative conventional reversed-phase HPLC method MLC was used for analysis of Biseptol (sulfamethoxazole and trimethoprim) tablets and injection. The MLC was proposed to assay of triprolydine hydrochloride and pseudoephedrine hydrochloride in tablets as alternative normal-phase HPLC method described in USP phamiacopoeia. 

Ms. Watson has diabetes and is taking tolbutamide (Orinase). Her primary care provider prescribes the combination drug sulfamethoxazole and trimethoprim (Septra) for a bladder infection. Discuss any instructions information you would give to Ms. Watson in the patient education session... 

Cotrimoxazole contains the synergstic antibiotics sulfamethoxazole and trimethoprim, which inhibit different steps in the prokaryotic synthesis of tetrahydrofolate. 

Co-trimoxazole refers to the combination of sulfamethoxazole and trimethoprim, which offers synergistic activity. Co-trimoxazole is associated... 

Important specifications for the manufacture of all solutions include assay and microbial limits. Additional important specifications for suspensions include particle size of the suspended drug, viscosity, pH, and in some cases, dissolution. Viscosity can be important, from a processing aspect, to minimize segregation. In addition, viscosity has also been shown to be associated with bioequivalency. pH may also have some meaning regarding effectiveness of preservative systems and may even have an effect on the amount of drug in solution. With regard to dissolution, there are at least three products that have dissolution specifications. These products include pheny-toin suspension, carbamazepine suspension, and sulfamethoxazole and trimethoprim suspension. Particle size is also important, and at this point it would seem that any... 

Clinical Use. Atovaquone (Mepron) is used primarily to treat the protozoon that causes toxoplasmosis and the fungus that causes pneumocystis pneumonia in immunocompromised patients.6 This drug is not typically the primary treatment for pneumocystis, but is often reserved for patients who cannot tolerate more traditional treatments using sulfamethoxazole and trimethoprim (see Chapter 34) or pentamidine (see later). Atovaquone can also be used to prevent and treat resistant cases of malaria, and the antimalarial effects of this drug seem especially useful when combined with proguanil.48... 

Other drugs studied by Moore et al. include chlorine containing photosensitizers (178), the effect of surfactants on photosensitizers (179), photosensitization by malarial drugs (180), nalidic and oxolinic acids (181), 6-mercaptopurine (182), azathioprine and nitroimidazole (183), 7-methylbenz[c]acridine and related products (184), naproxen, ben-oxaprofen and indomethacin (185), mefloquine (186), sulfamethoxazole and trimethoprim (187), benzydamine (188), photodecomposition of hydrochlorthiazide (189), tetracycline (190), frusemide (191), 6-mercaptopurine (192), 7-methylbenz[c]acridine (193), metronidazole, misonidazole and azathioprine (194), misonidazole and metronidazole (195), benzydamine (196), components in drug formulations (197) and sulfamethoxazole (198,199). 

Zhou W, Moore DE. Photosensitizing activity of the antibacterial drugs sulfamethoxazole and trimethoprim. Photochem Photobiol 1997 39 63-72. 

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... 

Fig. 6. Photomicrographs (magnification 200 x) of crystals showing modified habit produced after interaction between aqueous dispersions of sulfamethoxazole and trimethoprim molar ratio 5.73 1 (A) molar ratio 1 1 (B) HPMC added before mixing aqueous dispersions (C) HPMC added after mixing aqueous dispersions (D).

BerganT, Brodwall EK. Kidney transport in man of sulfamethoxazole and trimethoprim. Chemotherapy. 1972 17(5) 320-33. 

Sulfamethoxazole and Trimethoprim. The synergi.s-lic action of the combination of these two drugs is discussed above in this chapter. 

Q3.1 Co-trimoxazole tablets contain sulfamethoxazole and trimethoprim and are used in the treatment of chest and urinary tract infections. Classify sulfamethoxazole and trimethoprim as acidic, basic or neutral and hence describe how you could separate a mixture of the two drugs in the laboratory using simple glassware and reagents. See Figure 3.24. 

Sequential biochemistry interactions also fall within this category. Sulfamethoxazole and trimethoprim inhibit different stages of the folate metabolism pathway. Concomitant administration reduces the probability that a bacterial strain can mutate in any single step to evade the antibiotic effects of both drugs. 

Caumes E, Guermonprez G, Lecomte C, et al. Efficacy and safety of desensitization with sulfamethoxazole and trimethoprim in 48 previously hypersensitive patients infected with human immunodeficiency virus. Arch Dermatol 1997 133 465 69. 

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