Hepatic metabolism ciprofloxacin

The pharmacokinetics of enrofloxacin and its active metabolite, ciprofloxacin, have been further extensively studied in sea bass after treatment by oral gavage or water, at a temperature of 15 C (157). Enrofloxacin was absorbed and eliminated slowly after oral administration to the sea bass. Following bath treatment, enrofloxacin efficiently penetrated fish tissues but it was poorly metabolized compared with mammals. On the other hand, ciprofloxacin was generally detected in very low concentrations (less than 0.02 ppm) in plasma samples after both oral and bath treatment. Liver levels of ciprofloxacin were found to be 0.12 ppm after a 5 ppm bathing for 24 h, 0.06 ppm after a 10 ppm bathing for 8 h, and 0.33 ppm after a 50 ppm bathing for 4 h, suggestive of hepatic metabolism of enrofloxacin. 

PENTOXIFYLLINE ANTIBIOTICS Ciprofloxacin may t pentoxifylline levels Uncertain likely to be due to inhibition of hepatic metabolism Warn patients of the possibility of adverse effects of pentoxifylline... 

A significant fraction of each drug is excreted unchanged in the urine (by glomerular filtration and tubular secretion, e.g. norfloxacin and ciprofloxacin). Sparfloxacin and trovafloxacin have significant non-renal elimination pathways. Hepatic metabolism also takes place (e.g. nalidixic acid being converted to an active metabolite). 

Enzyme inhibition. Ciprofloxacin and cimetidine inhibit hepatic metabolism of lipid-soluble J-adrenoceptor blockers, e.g. metoprolol, labetalol, propranolol, increasing their effect. Methyldopa plus an MAO inhibitor may cause excitement and hallucinations. 

Fluoroquinolones. Ciprofloxacin and enoxacin (Pene-trex) may markedly increase serum concentrations of medications such as theophylline by inhibiting their hepatic metabolism. Certain other fluoroquinolones, such as levofloxacin (Levaquin), are not likely to inhibit hepatic enzyme systems and interact with these medications. 

Enrofloxacin is mainly eliminated by hepatic metabolism, and systemic clearance of the drug varies between species. In sheep, horses, dogs and pigs the average clearance of enrofloxacin is in the range 5.75-8.56 mL/min kg, while enrofloxacin clearance (mL/min kg) differs more widely between other species rabbits (17.9), llamas (12.0), chickens (3.3), turkeys (8.9), houbara bustard (5.7) and fingerling rainbow trout (Oncorhynchus mykiss) at 15°C (1.25). Systemic clearance of enrofloxacin represents mainly hepatic clearance composed of a variety of metabolic pathways, which include N-deethylation to ciprofloxacin. 

Rifampin is an effective inducer of hepatic P450 isozymes. Cyclosporine and tetracycline have no effects on drug metabolism. Ciprofloxacin and erythromycin are inhibitors of drug metabolism. The answer is (D). 

Fluoroquinolones alone rarely cause convulsions both in patients with and without a history of seizures. The mechanism for the effect of ciprofloxacin on phenytoin levels is unknown, and is unlikely to be due to effects on hepatic metabolism or oral absorption.However, ciprofloxacin decreased phenytoin levels in an animal study, and a suggested reason for this was increased urinary excretion. ... 

Elevations of serum transaminase concentrations generally are not correlated with the residual capacity of the liver to metabolize drugs, so these markers cannot be used directly as guides for residual metabolic capacity. Hepatically cleared TB drugs include isoniazid, rifampin, pyrazinamide, ethionamide, and p-aminosalicylic acid.39 Ciprofloxacin is about 50% cleared by... 

T Pancreatic insulin release Metformin Peripheral insulin sensitivity hepatic glucose output/production i intestinal glucose absorption Dose Ist-line (naive pts), 1.25/250 mg PO daily-bid 2nd-line, 2.5/500 mg or 5/500 mg bid (max 20/2000 mg) take w/ meals, slowly T dose hold before 48 h after ionic contrast media Caution [C, -] Contra SCr >1.4 mg/dL in females or >1.5 mg/dL in males hypoxemic conditions (sepsis, recent MI) alcoholism metabolic acidosis liver Dz Disp Tabs SE HA, hypoglycemia, lactic acidosis, anorexia, N/V, rash Additional Interactions T Effects W/ amiloride, ciprofloxacin cimetidine, digoxin, miconazole, morphine, nifedipine, procainamide, quinidine, quinine, ranitidine, triamterene,... 

Eszopiclone is metabolized in the liver by CYP 3A4. Eszopiclone should not be used in patients with severe hepatic impairment. Dose adjustment and caution are recommended in patients taking enzyme inhibitors such as ketoconazole, ciprofloxacin, erythromycin, iso-niazid, and nefazodone. Other sedative-hypnotics are not recommended with administration of this medication. 

Fluoroquinolones are potent inhibitors of hepatic cytochrome P450 isozymes (150). They inhibit theophylline metabolism, and accumulation of theophylline has led to seizures (151). Theophylline clearance is reduced by about 10% by norfloxacin, 30% by ciprofloxacin, and 70% by enoxacin (152-162). In a comparison of grepa-floxacin (400 and 600 mg/day) and ciprofloxacin, increased theophylline concentrations associated with clinical symptoms were found with both doses of grepa-floxacin but not in patients taking ciprofloxacin (17). The dosage of theophylline should be reduced when a quino-lone is given. 

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