With too little tryptophan in the blood, the body is unable to make a sufficient amount of the B-complex vitamin niacinamide, particularly under stress when more vitamins are needed.In Hartnup disease, urinary excretion of proline, hydroxyproline, and arginine remains unchanged, differentiating it from other causes of generalized aminoaciduria, such as Fanconi syndrome. With urine chromatography, increased levels of neutral amino acids (e.g., glutamine, valine, phenylalanine, leucine, asparagine, citrulline, isoleucine, threonine, alanine, serine, histidine, tyrosine, tryptophan) and indican are found in the urine. Increased urinary Indican can be tested by Obermeyer test. Treatment
A high-protein diet can overcome the deficient transport of neutral amino acids in most patients. Poor nutrition leads to more frequent and more severe attacks of the disease, which is otherwise asymptomatic. All patients who are symptomatic are advised to use physical and chemical protection from sunlight: avoid excessive exposure to sunlight, wear protective clothing, and use  chemical sunscreens with a SPF of 15 or greater. Patients also should avoid other aggravating factors, such as photosensitizing drugs, as much as possible. In patients with niacin deficiency and symptomatic disease, daily supplementation with nicotinic acid or nicotinamide reduces both the number and severity of attacks. Neurologic and psychiatric treatment is needed in patients with severe central nervous system involvement. See also
Citrullinemia
Cystinosis
Cystinuria

References


== External links ==
This inhibition prevents the conversion of lanosterol to ergosterol, an essential component of the fungal cytoplasmic membrane, and subsequent accumulation of 14α-methyl sterols. Fluconazole is primarily fungistatic; however, it may be fungicidal against certain organisms in a dose-dependent manner, specifically Cryptococcus. Pharmacokinetics
Following oral dosing, fluconazole is almost completely absorbed within two hours. Bioavailability is not significantly affected by the absence of stomach acid. Concentrations measured in the urine, tears, and skin are approximately 10 times the plasma concentration, whereas saliva, sputum, and vaginal fluid concentrations are approximately equal to the plasma concentration, following a standard dose range of between 100 mg and 400 mg per day. The elimination half-life of fluconazole follows zero order, and only 10% of elimination is due to metabolism, the remainder being excreted in urine and sweat. Patients with impaired renal function will be at risk of overdose.In a bulk powder form, it appears as a white crystalline powder, and it is very slightly soluble in water and soluble in alcohol. History
Fluconazole was patented by Pfizer in 1981 in the United Kingdom and came into commercial use in 1988. Patent expirations occurred in 2004 and 2005. References
External links
"Fluconazole". Drug Information Portal. U.S. National Library of Medicine. Doi : Evolution of Fluconazole-Resistant Candida albicans Strains by Drug-Induced Mating Competence and Parasexual Recombination