72120 38 gentamicin garamycin used to treat serious

This preview shows page 38 - 44 out of 51 pages.

7/21/20 38 Gentamicin [Garamycin] Used to treat serious infections caused by aerobic gram-negative bacilli Pseudomonas aeruginosa Escherichia coli Klebsiella Serratia Proteus mirabilis Adverse effects Nephrotoxicity Ototoxicity 75 75 Sulfonamides and Trimethoprim Broad-spectrum antibiotics Have closely related mechanisms Suppress bacterial growth by inhibiting tetrahydrofolic acid, a derivative of folic acid or folate 76 76
7/21/20 39 Sulfonamides First drugs available for systemic treatment of bacterial infection More effective and less toxic drugs are now available Inhibit the synthesis of folic acid (folate) Mammalian cells do not manufacture their own folate (not affected as bacteria are affected) Primary use now: Urinary tract infection (UTI) Other uses: Nocardiosis, Chlamydia trachomatis, conjugation therapy for toxoplasmosis/malaria, ulcerative colitis 77 77 Sulfonamides Adverse effects Hypersensitivity reactions: Stevens-Johnson syndrome Hematologic effects (hemolytic anemia) Kernicterus Renal damage from crystalluria Drug interactions Metabolism-related interactions: can intensify effects of some drugs (warfarin, phenytoin, sulfonylureas Cross-hypersensitivity with other drugs (thiazide diuretics, loop diuretics, & sulfonylureas) 78 78
7/21/20 40 Trimethoprim Inhibits dihydrofolate reductase, the enzyme that converts dihydrofolic acid to its active form, tetrahydrofolic acid, thus suppressing bacterial synthesis of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and proteins Uses Acute and uncomplicated UTIs Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter, coagulase-negative Staphylococcus 79 79 Trimethoprim Adverse effects Hematologic effects (megoblastic anemia, thrombocytopenia, & neutropenia) Hyperkalemia Use in pregnancy and lactation (teratogenic in animal studies – can cause folate deficiency) 80 80
7/21/20 41 Trimethoprim/Sulfamethoxazole Trimethoprim/sulfamethoxazole (TMP/SMZ) combination: Inhibits sequential steps in bacterial folic acid synthesis, making it much more powerful than TMP or SMZ alone Plasma drug levels to achieve 1:20 ratio Therapeutic uses UTI, otitis media, bronchitis, shigellosis, pneumonia caused by Pneumocystis jiroveci, Pneumocystis pneumonia, and GI infection 81 81 Trimethoprim/Sulfamethoxazole Adverse effects Gastrointestinal Nausea and vomiting Rash Hyperkalemia Hypersensitivity reactions (Stevens-Johnson syndrome) Blood dyscrasias Kernicterus Renal damage: Crystalluria 82 82
7/21/20 42 Antimicrobial Drugs II Part 4 83 Miscellaneous Antibacterial Drugs: Fluoroquinolones, Metronidazole, Daptomycin, Rifampin, Rifaximin, Bacitracin, and Polymyxins 84
7/21/20 43 Fluoroquinolones Broad-spectrum agents with multiple applications Disrupt DNA replication and cell division All can be administered orally or IV 85 85 Fluoroquinolones Side effects generally mild but can cause tendon rupture (low risk) Usually affects Achilles tendon Avoid in patients younger than 18 years Risk to all patients, especially those older than 60 years, those taking glucocorticoids, and those who have undergone kidney, heart, or lung transplantation 86 86

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture