Phototherapy, hyperbilirubinemia

Phototherapy The use of ultraviolet light applied to the skin, for example in treating psoriasis or neonatal hyperbilirubinemia. 

The forms of phototherapy in common use include (i) the phototherapy of jaundice (neonatal hyperbilirubinemia) in the newborn, and especially in the prematurely born 5 (ii) the treatment of psoriasis using light in the UV-A range (320 100 nm) and an administered photosensitizer, such as 8-methoxypsoralen 6 (iii) the treatment of the wet form of age-related macular degeneration with a photosensitizer such as a benzoporphyrin derivative (VISUDYNE ), and a laser light source 7 and (iv) the treatment of certain cancers with a photosensitizer such as a porphyrin derivative, and red light.8... 

For many years, phototherapy has been the standard treatment of neonatal hyperbilirubinemia. The effectiveness of this form of therapy is based on the ability of photons of the appropriate wavelength to convert the intramolecularly H-bonded bilirubin IXa with its low solubility into photoisomers of bilirubin in which the normal Z,Z stereochemistry at the 4- and 15-positions is changed, resulting in photoisomers that are more water soluble. In addition, bilirubin can be converted into the cyclic lumirubin, which is soluble and can be excreted in the urine (Fig. 22-2). Photoproducts can also be excreted through the liver pathway without... 

Photolysis of riboflavin occurs in vivo during phototherapy for neonatal hyperbilirubinemia (Section 7.4.4). There is no evidence that normal exposure to sunlight results in significant photolysis of riboflavin, although it is possible that some of the lumichromes found in urine may arise in this way. 

Neonatal hyperbilirubinemia is normally treated by phototherapy. The peak wavelength for photolysis of bilirubin is 450 nm, the same as that for photolysis of riboflavin (Section 7.1). Infants undergoing phototherapy show biochemical evidence of riboflavin depletion, with a significant increase in the EGR activation coefficient. Provision of additional riboflavin to maintain plasma concentrations enhances the photolysis of bilirubin, apparently as a result of reactive oxygen radicals generated by the products of photolysis of riboflavin. 

Special illuminating conditions need to be considered during the blue-lamp phototherapy for neonatal jaundice (hyperbilirubinemia). In practice, the neonate is placed under a blue fluorescent lamp having a at about 450 nm, at an irradiance level between 4 and 6 pW/cm. This procedure is very effective in decreasing serum bilirubin concentrations. The high irradiance levels used in phototherapy may also enhance the degradation of drugs in concurrent use. 

Caglayan, S., Candemir, H., Aksit, S., Kansov, S., Asik, S., Yapiak, I. Superiority of oral agar and phototherapy combination in the treatment of neonatal hyperbilirubinemia. Pediatrics 1993 92 86-89... 

Riboflavin decomposes when exposed to visible light. This characteristic can lead to riboflavin deficiencies in newborns treated for hyperbilirubinemia by phototherapy. 

Sulfonamides should not be given to pregnant women in the third trimester of pregnancy. They can displace bilirubin from plasma albumin and cause kernicterus (bilirubin encephalopathy) (205-208). For the same reason, the administration of sulfonamides to lactating women or premature infants should be avoided. Successful treatment of neonatal hyperbilirubinemia with higher bilirubin concentrations has been established using exchange transfusion and phototherapy. 

The complex formation of bilirubin with human serum albumin was investigated by Sinclair et al. 72) using 347 nm ruby laser flash photolysis technique. A high bilirubin level is found in new bom babies who suffer from jaundice (neonatal hyperbilirubinemia)73). Phototherapy has been found to be suitable for lowering the bilirubin level. In order to understand the mechanism of the phototherapy, investigation into the photophysics of bilirubin is essential. It is strongly bound to human serum albumin, lipids and cell membranes. 

Chemoprotective agent for cisplatin and cyclophosphamide Hypercalcemia of malignancy Hemophilia A and B Congenital factor XIII deficiency Lennox-Gastaut syndrome Colonic adenomatous polyps Treatment of hepatitis B Corneal ulcers Myelodysplastic syndrome Diagnosing allergy to fire ant Non-Hodgkin s lymphoma Hyperbilirubinemia in newborns unresponsive to phototherapy... 

Further, blue-emitting Sr2P207 Eu, with an emission maximum at 420 nm and q 90%, can be used in lamps in the phototherapy of hyperbilirubinemia (an excess of bilirubin in the blood serum which may result in permanent brain damage in newborn infants). 

Neonatal hyperbilirubinemia associated with glucose-6-phosphate dehydrogenase deficiency in Sephardic-Jewish neonates incidence, severity, and the effect of phototherapy. 

The most severe porphyrias with cutaneous symptomatology are the two autosomal recessive forms, congenital erythropoietic porphyria (31.3) and hepatoerythropoietic porphyria (31.8). Both disorders show a great variability of disease course, that varies from intrauterine hydrops fetalis with severe hemolytic anemia, over neonatal onset with red urine, prolonged hyperbilirubinemia and acute severe skin lesions induced by phototherapy, up to the relatively benign forms with late onset not before adult life. The... 

In neonates suspected to have any congenital form of porphyria (red urine with pink fluorescence under long UV light) avoid phototherapy for hyperbilirubinemia ... 

Liver Ibuprofen has been hnked with hyperbilirubinemia in preterm neonates. In a retrospective comparison of 418 preterm infants receiving ibuprofen prophylaxis of patent ductus arteriosus and 288 infants who were not treated with ibuprofen those who received ibuprofen had a higher peak serum bilirubin concentration, needed more phototherapy, and had a longer duration of phototherapy [43. ... 

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