Pyridoxine interaction

Levodopa interacts with many different drugs. When levodopa is used with phenytoin, reserpine, and papaverine, there is a decrease in response to levodopa The risk of a hypertensive crisis increases when levodopa is used with the monoamine oxidase inhibitors (see Chap. 31). Foods high in pyridoxine (vitamin B6) or vitamin B6 preparations reverse the effect of levodopa However, when carbidopa is used with levodopa, pyridoxine has no effect on the action of levodopa hi fact, when levodopa and carbidopa are given together, pyridoxine may be prescribed to decrease the adverse effects associated with levodopa... 

Phenomenex (see 2006 Catalog, SPE products) Strata-X Polar functionalized styrene-divinylbenzene polymer Reversed phase with weakly acidic, hydrogen bond donor, acceptor, and dipolar interactions Cetirizine (76) pyridoxine (77) omeprazole (78) mycophenolic acid (79) 25-hydroxy-vitamin D3 (80)... 

Pyridoxine [Vitamin B ] [Vitamin B Supplement] U e Rx prevention of vit B6 deficiency Action Vit supl Dose Adults. Deficiency 10-20 mg/d PO Drug-induced neuritis 100-200 mg/d 25-100 mg/d prophylaxis Peds. 5-25 mg/d x 3 wk Caution [A (C if doses exceed RDA), +] Contra Component aUCTgy Disp Tabs 25, 50, 100 mg inj 100 mg/mL SE Allergic Rxns, HA, N Interactions -1- Effects OF levodopa, phenobarbital, phenytoin EMS Can be used as an antidote for isoniazid poisoning OD May cause sensory nerve damage (numbness, tingling, reduced sensation) and coordination problems Sxs are usually revised aft stopping pyridoxine symptomatic and supportive... 

Isoniazid (child 10 mg/kg up to) 300 mg orally, for 6 months 15 mg/kg orally, for 6 months 15 mg/kg orally, for 6 months Hepatic enzyme elevation Hepatitis Peripheral neuropathy CNS (mild) Drug interactions Hepatitis risk increases with age and alcohol consumption. Pyridoxine can prevent peripheral neuropathy... 

Pyridoxine [P] Inhibited antiparkinsonism effect (carbidopa prevents the interaction). 

Isoniazid Isoniazid is incompatible with sugars. Isoniazid overdose may be severe to fatal, and treatment is symptomatic and supportive, including stomach wash for control of convulsions and treating metabolic acidosis. Administration of pyridoxine and hemodialysis may be needed. Isoniazid interacts with carba-mazepine, phenytoin, diazepam, triazolam, chlorzoxazone, theophylline, ethosux-imide, enflurane, cycloserine, and warfarin. 

Interactions The vitamin pyridoxine (B6) increases the peripheral breakdown of levodopa and diminishes its effectiveness (Figure 8.6). Concomitant administration of levodopa and monoamine oxidase (MAO) inhibitors, such as phenelzine (see p. 124), can produce a hypertensive crisis caused by enhanced catecholamine production therefore, caution is required when they are used simultaneously. In many psychotic patients, levodopa exacerbates symptoms, possibly through the buildup of central amines. In patients with glaucoma, the drug can cause an increase in intraocular pressure. Cardiac patients should be carefully monitored because of the possible development of cardiac arrhythmias. Antipsychotic drugs are contraindicated in parkinsonian patients, since these block dopamine receptors and produce a parkinsonian syndrome themselves. 

Glutamate is utilized in metabolic interaaions with other amino acids and is formed into new proteins. One route by which glutamate can be removed is through reaaions that require vitamin B6 (pyridoxine), and individuals who are deficient in this vitamin may suffer greater effeas from excess MSG. Glutamate also has an important role in the brain where it acts as an excitatory neurotransmitter, increasing the aaivity of nerve cells, ft is responsible for most of the interactions between nerve cells in the brain, for example those involved in memory... 

Vitamin B complex is the collective term for a number of water-soluble vitamins found particularly in dairy products, cereals and liver.Vitamin B (thiamine) is used by mouth for dietary supplement purposes and by injection in emergency treatment of Wernicke-Korsakoff syndrome. Vitamin B2 (riboflavin) is a constituent of the coenzyme FAD (flavine adenine dinucleotide) and FMN (flavine mononucleotide) and is therefore important in cellular respiration. Vitamin Be (pyridoxine) is a coenzyme for decarboxylases and transamination, and is concerned with many metabolic processes. Overdose causes peripheral neuropathy. It may be used medically for vomiting and radiation sickness and for premenstrual tension. Pyridoxine has a negative interaction with the therapeutic use of levodopa in parkinsonism by enhancing levodopa decarboxylation to dopamine in the periphery, which does not then reach the brain. The antitubercular drug isoniazid interferes with pyridoxine, and causes a deficiency leading to peripheral neuritis that may need to be corrected with dietary supplements. Vitamin B ... 

Clinically important, potentially hazardous interactions with amisulpride, kava, MAO inhibitors, phenelzine, pyridoxine, sapropterin, selegiline, sulpiride, tetrabenazine, tranylcypromine, zuclopenthixol, zudopenthixol acetate, zudopenthixol decanoate, zuclopenthixol dihydrochloride... 

Photoinduced processes arising from interaction between triplet an-thraquinone and various amines have been studied. A review has highlighted the progress of the development of photochromic materials based on naph-thacenequinones. ° Broumische and Wan have reported the formation of o-quinonemethide intermediates on the irradiation of pyridoxine and some of its derivatives. ... 

The reaction has been very useful for the synthesis of substituted py-ridines, particularly pyridoxine (vitamin Be) and its homologs and analogs. In the last decade a number of papers and patents dealing with the interaction of oxazoles with dienophiles, leading to pyridines, have appeared, they were critically reviewed by Karpeiskii and Florent ev11 in 1969. Therefore, reactions leading to pyridines are described here only briefly, in order to give a clear picture of the scope of the reaction. 

Toxicity and interactions Neurotoxic effects are common and include peripheral neuritis, restlessness, muscle twitching, and insomnia. These effects can be alleviated (without blocking the antibacterial effect) by administration of pyridoxine. INH is hepatotoxic and may cause abnormal liver function tests, jaundice, and hepatitis. Fortunately, hepatotoxicity is rare in children. INH may inhibit the hepatic metabolism of dmgs, eg, phenytoin. Hemolysis has occurred in patients with glucose-6-phosphate dehydrogenase deficiency. A lupuslike syndrome has been reported. 

This paper will review what is presently known about interactions between vitamins and oral contraceptives. It is clearly important to assess carefully the evidence available with regard to each vitamin and to point out that much remains to be learned about normal vitamin metabolism and the metabolic pathways in which they serve as important coenzymes. The normal metabolism of pyridoxine and folic acid will be discussed in some detail, since they have received the greatest attention by investigators. 

Pyridoxine 200 mg daily for 4 weeks reduced the phenobarbital serum levels of 5 epileptics by about 50%. Reductions in serum phenytoin levels of about 35% (range 17 to 70%) were also seen when patients were given pyridoxine 80 to 400 mg daily for 2 to 4 weeks. However, no interaction occurred in a number of other patients taking these drugs. ... 

Information seems to be limited, but what is known suggests that concurrent use should be monitored if large doses of pyridoxine or nicotinamide are used, being alert for the need to modify the antiepileptic dosage. It seems unlikely that small doses (as in multivitamin preparations) will interact to any great extent. 

The effects of levodopa are reduced or abolished by pyridoxine, but this interaction does not occur when ievodopa is given with the dopa-decarboxyiase inhibitors carbidopa or benserazide, as is usuai ciinicai practice. 

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