Quinolones Folic Acid Antagonists Urinary Tract Antiseptics

Fluoroquinolones Bactericid

Ciprofloxacin Useful in treating infections caused by many Enterobacteriaceae & other gram-negative bacilli (E. coli). The drug of choice for prophylaxis and treatment of anthrax The most potent of the fluoroquinolones for Pseudomonas aeruginosa infections Alternative to more toxic drugs, such as the aminoglycosides Act synergistically with β-Iactams, and is also of benefit in treating resistant tuberculosis

Levels are high in bone, urine, kidney & prostatic tissue (but not prostatic fluid) Concentrations in the lung exceed those in serum Penetration into cerebrospinal fluid is low except for ofloxacin, for which concentrations can be as high as ninety percent of those in the serum The fluoroquinolones also accumulate in macro phages and polymorphonuclear leukocytes, thus being effective against intracellular organisms such as Legionella pneumophila.

Adverse reactions Gastrointestinal: nausea, vomiting, and diarrhea Central nervous system problems: headache & dizziness or lightheadedness (Cautiously in epilepsy) Phototoxicity Liver toxicity: Trovafloxacin Connective tissue problems: should be avoided in pregnancy, nursing mothers & children under eighteen years Contraindications: Sparfloxacin & Moxifloxacin prolong the QT interval and, thus, should not be used in patients who are predisposed to arrhythmias or are taking antiarrhythmic medications

Drug interactions: Ciprofloxacin & Ofloxacin: increase the serum levels of theophylline by inhibiting its metabolism Third- and fourth-generation: raise the serum levels of warfarin, caffeine & cyclosporine Cimetidine interferes with elimination of the fluoroquinolones

SULFONAMIDES Bacteriostatic

Sulfasalazine is not absorbed orally or as suppository: For treatment of chronic inflammatory bowel disease (for example, Crahn disease or ulcerative colitis) Local intestinal flora split sulfasalazine into sulfapyridine and 5-aminosalicylate, with the latter exerting the anti-inflammatory effect

Adverse effect Crystalluria Hypersensitivity Hemopoietic disturbances: with glucose 6-phosphate dehydrogenase deficiency Kernicterus Contraindications: should be avoided in newborns and infants less than two months of age, as well as for pregnant women at term should not be given to patients receiving methenamine for UTls

TRIMETHOPRIM may be used alone in the treatment of acute UTls treatment of bacterial prostatitis (although fluoroquinolones are preferred) and vaginitis دفع کلیوی administration of folinic acid

CO-TRIMOXAZOLE: (trimethoprim + sulfamethoxazol)

Adverse effects: Hematologic: Megaloblastic anemia (folinic acid) Hemolytic anemia (glucose 6-phosphate dehydrogenase defi- iency due to the sulfamethoxazole)

Drug Interactions: Prolonged prothrombin times in patients receiving both trimethoprim and warfarin The plasma half-life of phenytoin may be increased Methotrexate levels may rise due to displacement from albumin binding sites by sulfamethoxazole

URINARY TRACT ANTISEPTICS A. Methenamin Orally Contraindicated in patients with hepatic insufficiency Eliminated in the urine

Adverse effects: The major side effect : gastrointestinal distress at higher doses: albuminuria, hematuria, and rashes Methenamine mandelate is contraindicated in patients with renal insufficiency, because mandelic acid may precipitate Sulfonamides react with formaldehyde, and must not be used concomitantly with methenamine

B. Nitrofurantoin Less common because of its narrow antimicrobial spectrum and toxicity Sensitive bacteria reduce the drug to an active agent that inhibits various enzymes and damages DNA Antibiotic activity is greater in acidic urine Bacteriostatic Useful against E. coli, but other common urinary tract gram-negative bacteria may be resistant Gram-positive cocci are susceptible Adverse effects: Gastrointestinal disturbances, acute pneumonitis, and neurologic problems