Thyroid hormones Theophylline

Agents that may increase theophylline levels include allopurinol, beta blockers (nonselective), calcium channel blockers, cimetidine, oral contraceptives, corticosteroids, disulfiram, ephedrine, influenza virus vaccine, interferon, macrolides, mexiletine, quinolones, thiabendazole, thyroid hormones, carbamazepine, isoniazid, and loop diuretics. 

Rifampin is known to induce the hepatic microsomal enzymes that metabolize various drugs such as acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta blockers, chloramphenicol, clofibrate, oral contraceptives, corticosteroids, cyclosporine, disopyramide, estrogens, hydantoins, mexiletine, quinidine, sulfones, sulfonylureas, theophyllines, tocainide, verapamil, digoxin, enalapril, morphine, nifedipine, ondansetron, progestins, protease inhibitors, buspirone, delavirdine, doxycycline, fluoroquinolones, losartan, macrolides, sulfonylureas, tacrolimus, thyroid hormones, TCAs, zolpidem, zidovudine, and ketoconazole. The therapeutic effects of these drugs may be decreased. 

Levodopa or dopamine agonists produce diverse dyskinesias as a dose-related phenomenon in patients with Parkinson s disease dose reduction reverses them. Chorea may also develop in patients receiving phenytoin, carbamazepine, amphetamines, lithium, and oral contraceptives, and it resolves with discontinuance of the offending medication. Dystonia has resulted from administration of dopaminergic agents, lithium, serotonin reuptake inhibitors, carbamazepine, and metoclopramide and postural tremor from theophylline, caffeine, lithium, valproic acid, thyroid hormone, tricyclic antidepressants, and isoproterenol. 

Metaproterenol (Alupent, Metaprel) [Bronchodilator/ Beta-Adrenergic Agonist] Uses Asthma reversible bronchospasm Action Sympathomimetic bronchodilator Dose Adults. Neb 0.2-0.3 mL in 2.5-3.0 mL of NS Peds. Neb 0.1-0.2 mL/kg of a 5% soln in 2.5 mL NS Caution [C, /-] Contra Tach, other arrhythmias Disp Aerosol 0.65 mg/inhal soln for inhal 0.4, 0.6% tabs 10, 20 mg syrup 10 mg/5 mL SE Nervousness, tremors (common), tach, HTN Interactions T Effects W/ sympathomimetic drugs, xanthines T risk of arrhythmias W/ cardiac glycosides, halothane, levodopa, theophylline, thyroid hormones T HTN W/ MAOIs effects W/ BBs EMS Separate additional aerosol use by 5 min fewer 3i effects than isoproterenol longer-acting monitor lung sounds before/after administration... 

One of the first applications of HPLC in the clinical field was the quantitation of theophylline in asthmatic infants. This highly accurate measurement was an important test because of the very low amount of sample required and the accuracy of the determination (see Fig. 1-10). More recent clinically related HPLC separations include drugs and drug metabolites, neurochemicals and their metabolites, histamines, thyroid hormones, and enkephalins. The earliest bioresearch applications of HPLC included the determination of peptides, proteins, and amino acids. Application of HPLC to the analysis of these compounds remains important, as indicated by the rapid growth in references (Fig. 1-11). Bioresearch remains one of the most rapidly expanding growth areas of LC. 

THYROID HORMONES BRONCHODILATORS- THEOPHYLLINE Altered theophylline levels (T or f) when thyroid status was altered therapeutically Uncertain Monitor theophylline levels closely during changes in treatment of abnormal thyroid function. Watch for early features of theophylline toxicity... 

Antidepressants selective serotonin reuptake inhibitors, tricyclic antidepressants Antihypertensives felodipine Antibiotics quinolones, isoniazid Bronchodilators albuterol, theophylline Corticosteroids prednisone Dopa agonists levodopa Herbals ma huang, ginseng, ephedra Nonsteroidal anti-inflammatory drugs ibuprofen Stimulants amphetamines, methylphenidate, caffeine, cocaine Sympathomimetics pseudoephedrine Thyroid hormones levothyroxine Toxicity anticholinergics, antihistamines, digoxin Withdrawal alcohol, sedatives... 

Theophylline, asthma, 17.2, 18.1, 18.2 Thiazides, see Diuretics Thiazolidinediones cardiovascular reactions, 31.697 musculoskeletal reactions, 32.779 peripheral edema, 29.531 Thiomersal, in vaccines, 28.357 Thiopurines, genetic susceptibility, 31.634 Thyroid hormones, 29.464 Thyroxine, drug interactions, 24.484 Tiaprofenic acid, cystitis, 18.106 TNF, see tumor necrosis factor Tolcapone, 32.289... 

Adrenocorticotropic hormone, a-amylase, atrazineAriazines, 2,4-dinitrophenyl lysine, human chorionic gonadotropin, human serum albumin, immunoglobulin G, isoproturon, parathyroid hormone, testosterone, theophylline, thyroid stimulating hormone, thyroxine, transferrin, transferrin, trinitrotoluene... 

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