Vitamin barbiturates

Maintenance doses widely vary among patients (e.g., from 1 to 20 mg/day for warfarin), and are influenced by diet (variable vitamin K intake) and medications that affect coumarin metabolism (decreased drug clearance e.g., cotrimoxazole, amiodarone, erythromycin increased clearance e.g., barbiturates, carbamaze-pine, rifampin). Thus, regular monitoring is needed... 

The effects of warfarin may increase when administered with acetaminophen, NSAIDs, beta blockers, disulfiram, isoniazid, chloral hydrate, loop diuretics, aminoglycosides, cimetidine, tetracyclines, and cephalosporins. Oral contraceptives, ascorbic acid, barbiturates, diuretics, and vitamin K decrease the effects of warfarin. Because die effects of warfarin are influenced by many drugp, die patient must notify die nurse or die primary healdi care provider when taking a new drug or discontinuing... 

Might antagonize verapamil Might induce hypercalcemia with thiazide diuretics Fiber laxatives (variable), oxalates, phytates, and sulfates can decrease calcium absorption if given concomitantiy Phenytoin, barbiturates, carbamazepine, rifampin increase vitamin D metabolism... 

A large number of hormones and drugs which find their abundant usage in a bad way, namely cortisol (17-hydroxycorticosterone or hydrocortisone), insulin, morphine, barbiturates (sedatives), vitamin B12, digoxin and human growth hormones, such as somatotropin (elaborated in the placenta),... 

Effects on vitamin D Barbiturates may increase vitamin D requirements, possibly by increasing the metabolism of vitamin D via enzyme induction. 

Drugs that may affect chloramphenicol include barbiturates, rifampin, and hydantoins. Drugs that may be affected by chloramphenicol include barbiturates, anticoagulants, cyclophosphamide, hydantoins, iron salts, penicillins, sulfonylureas, and vitamin B- 2-... 

Hauptmann accidentally discovers barbiturates as anticonvulsants (see 1903, 1882) Loewi demonstrates that acetylcholine is a neurotransmitter Banting and Best purify insulin as treatment for diabetes Szent-Gyorgyi isolates ascorbic acid (Vitamin C)... 

During the acute phase of thyrotoxicosis, B-adrenoceptor blocking agents without intrinsic sympathomimetic activity are extremely helpful. Propranolol, 20-40 mg orally every 6 hours, will control tachycardia, hypertension, and atrial fibrillation. Propranolol is gradually withdrawn as serum thyroxine levels return to normal. Diltiazem, 90-120 mg three or four times daily, can be used to control tachycardia in patients in whom blockers are contraindicated, eg, those with asthma. Other calcium channel blockers may not be as effective as diltiazem. Adequate nutrition and vitamin supplements are essential. Barbiturates accelerate T4 breakdown (by hepatic enzyme induction) and may be helpful both as sedatives and to lower T4... 

Clinical Chemistry (see Chapter 10). Gas chromatography is adaptable to such samples as blood, urine, and/or biological fluids. Compounds such as proteins, carbohydrates, amino acids, fatty acids, steroids, triglycerides, vitamins, and barbiturates are handled by this technique, directly or after preparation of appropriate volatile derivatives. 

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. 

Iodide in vitamin tablets can be found by amperometric detection [88]. Nonaqueous eluents of methanol-containing ammonium perchlorate, which are relatively oxidant resistant, have been used in conjunction with a silica column to detect a wide range of drugs [89]. The use of higher potentials not possible in totally aqueous mobile phases allows for the detection of secondary and tertiary aliphatic amines 462 drugs have been detected in this manner. For compounds that are not electroactive, a procedure using a postcolumn photolysis can generate electroactive species [90] for penicillins [91], proteins [92], and barbiturates [93]. 

BARBITURATES VITAMIN B6 1 plasma concentrations of these antiepileptics Uncertain Watch for poor response to these antiepileptics if large doses of vitamin B6 are given... 

VITAMIN D ANTIEPILEPTICS-PHENYTOIN, CARBAMAZEPINE, PRIMIDONE, BARBITURATES 1 efficacy of vitamin D Attributed to induction of vitamin D metabolism Be aware consider t dose of vitamin D... 

In adults, excessive alcohol consumption reduces liver reserves of vitamin A, both as a result of alcoholic liver damage and also by induction of cytochrome P450 enzymes that catalyze the oxidation of retinol to retinoic acid (as also occurs with chronic use of barbiturates). However, chronic consumption of alcohol can also potentiate the toxicity of retinol (Section 2.5.1). 

Compounds that induce cytochrome P450-dependent hydroxylases, such as barbiturates and the anticonvulsants primidone and diphenylhydantoin, cause increased output of vitamin D metabolites in the bile, and increase the rate of inactivation of calcidiol by liver microsomes. As a result of this, longterm use of these anticonvulsants may be associated with the development of... 

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