Hormonal Levodopa

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. 

Dopamine, abbreviated DA, is a biosynthetic compound and neurotransmitter produced in the body from the amino acid tyrosine by several pathways. It is synthesized in the adrenal gland where it is a precursor to other hormones (see Epinephrine) and in several portions of the brain, principally the substantia nigra and hypothalamus. Dopamine is stored in vesicles in the brain s presynaptic nerve terminals. It is closely associated with its immediate precursor, L-Dopa (levodopa). Casmir Funk (1884—1967) first synthesized Dopa in racemic form... 

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... 

Normal growth hormone concentrations are found in car-bamazepine-treated patients (94). Growth hormone secretion in response to levodopa stimulation was not affected by carbamazepine or phenobarbital, whereas phenytoin and anticonvulsant polytherapy caused an increase in growth hormone concentration, and valproate a fall at varying times after the administration of levodopa (95). Pubertal growth arrest has been described in a 12-year-old girl who had taken valproate for 18 months (SED-13,152). 

Levodopa usually increases plasma growth hormone concentrations (594). 

Galea-Debono A, Jenner P, Marsden CD, Parkes JD, Tarsy D, Walters J. Plasma DOPA levels and growth hormone response to levodopa in parkinsomism. J Neurol Neurosurg Psychiatry 1977 40(2) 162-7. 

Norepinephrine, together with epinephrine and dopamine (DA), belongs to the catecholamine family of hormones and neurotransmitters. DA is synthesized in all catecholamine neurons by decarboxylation of levodopa. This process is catalyzed by aromatic... 

Inhibition of Thyrotropin Releasing Dopamine, levodopa, corticosteroids, Hormone (TRH) or Thyroid somatostatin... 

Valproate caused a fall in growth hormone concentrations at varying times after the administration of levodopa (134). 

Eddy RL, Jones AL, Chakmakjian ZH, Sdverthorne MC. Effects of levodopa (L-dopa) on human hypophyseal tropic hormone release, J Clin Endocrinol Metab 1971 33 709-12. 

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... 

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