Cholestyramine antagonists

Drugs that may affect sulfonylureas include androgens, anticoagulants, azole antifungals, barbiturates, beta blockers, calcium channel blockers, charcoal, chloramphenicol, cholestyramine, ciprofloxacin, clofibrate, corticosteroids, diazoxide, estrogens, ethanol, fluconazole, gemfibrozil, histamine H2 antagonists, hydantoins,... 

Raloxifene (Evista) is a new SERM approved for use in the treatment and prevention of osteoporosis because it has estrogenic activity in bone. Raloxifene is an estrogen antagonist in both breast and endometrial tissues. The estrogenhke properties of raloxifene result in the maintenance of a favorable serum Upid profile (decreased low-density lipoprotein levels with no change in either high-density lipoproteins or triglycerides). Raloxifene is 95% bound to plasma proteins. Absorption of raloxifene is impaired by cholestyramine. 

Warfarin antagonists include vitamin K, barbiturates, glutethimide. rifampin, and cholestyramine. Warfarin potentiators include phenylbutazone. oxyphenbutazone, anabolic steroids, clofibrate, aspirin, hepatotoxins, disnlfirain, and metronidazole. In patients undergoing anticoagulation therapy with warfann, it has been found that cimetidine (used in therapy of duodenal ulcer) may increase anticoagulant blood levels and consequently prolong the prothrombin time. 

Treatment of icteric episodes with phenobarbital (3 x 20-60 mg/day) together with phototherapy (430-470 nm, 8-12 hr/day) and/or plasmapheresis is indicated. Cholestyramine (3x4 g/day) or cholestipol (3x5 g/day) may be used to treat pruritus. Qther recommended effective antipruritics are naloxone (2-3 x 0.4 mg/day, i.v.) or naltrexone (2-4 x 25-50 mg/day), which act as opi-oidergic neurotransmitters. (69) It is also possible to use the 5-HT3 antagonist ondansetron (3 x 4.8 mg/day, i.v. or orally). (64) Refractory cholestasis pruritus has recently been treated successfully with dronabinol (50) and also with sertraline. Administration of ursodeoxycholic acid (22, 53), medium-chain fatty acids, PUFA (65) and fat-soluble vitamins (especially vitamin K) is recommended. (s. pp 6, 47) (s. tab. 13.11)... 

Aluminum salts, cholestyramine, and colestipol may decrease absorption of /3 blockers. Pheny-toin, rifampin, and phenobarbital, as well as smoking, induce hepatic biotransformation enzymes and may decrease plasma concentrations of /3 receptor antagonists that are metabolized extensively (e.g., propranolol). Cimetidine and hydralazine may increase bioavailability of propranolol and metoprolol by affecting hepatic blood flow, fi Receptor antagonists can impair the clearance o/lidocaine. 

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