Photosensitivity reactions cause

Arata J, Horio T, Soejima R, Ohara K. Photosensitivity reactions caused by lomefloxacin hydrochloride a multicenter survey. Antimicrob Agents Chemother 1998 42(12) 3141-5. 

All fluoroquinolone drugs can cause pain, inflammation, or rupture of a tendon. The Achilles tendon is particularly vulnerable. This problem can be so severe tiiat prolonged disability results, and, at times, surgical intervention may be necessary to correct die problem, hi addition, the fluoroquinolone drugs, particularly sparfloxacin and lomefloxacin, cause dangerous photosensitivity reactions. Fhtients have experienced severe reactions even when sunscreens or sunblocks were used. 

Thiazide and related diuretics, loop diuretics, potassium-sparing diuretics, carbonic anhydrase inhibitors, triamterene Avoid exposure to sunlight or ultraviolet light (sunlamps, tanning beds) because exposure may cause exaggerated sunburn (photosensitivity reaction). Wear sunscreen and protective clothing until tolerance is determined. 

Avoid exposure to direct sunlight as this may cause a photosensitivity reaction... 

For photosensitization to occur light must be absorbed by the photosensitizer and cause a reaction to take place in the biological system ( ). Two main types of photosensltlzatlon are known to occur. Those involving O2 are called photodynamic sensitizations and are mediated by the bulk of the 400 synthetic and natural photosensitizers known O). The second type of photosensltlzatlon does not Involve O2 and is associated with the furanocoumarlns. 

The rate of reaction (33) is ten times that of (34). Presumably, the transition to (9, 0) of the 0 system in H8II state is affected by light of wavelength 1860 A. Flory and Johnston studied the mercury photosensitized reaction with a low-pressure Hg resonance lamp over the region 0.02-7 mm. The reaction rate was followed by the pressure change during the reaction, which was caused by the reaction of 02 with mercury. 

Chlorpromazine most often causes photosensitivity reactions (incidence around 3%), which may result from formation of a cytotoxic by-product after exposure to ultraviolet light. Patients should be advised to avoid prolonged exposure to strong indoor light, to wear protective clothing, and to use a combined para-aminobenzoic acid plus benzophenone sunscreen when exposure to strong sunlight is unavoidable. 

UVC (100 to 290 nm) is mainly filtered by the o2one layer but can be found in artificial situations such as arc welding lamps. UVB (290 to 320 nm) causes sunburn and is responsible for most of the harmful effects of UV radiation. UVA (320 to 400 nm) produces tanning and the photosensitivity reaction.The cornea absorbs UV radiation up to 295 nm, primarily in the epitheliiun and Bowman s membrane. 

Bithionol is a chlorinated bisphenol with antihehninthic properties. It is active against most trematodes and has been recommended as preferable to praziquantel in fascioliasis and paragonimiasis, proving both effective and well tolerated. Bithionol also has antibacterial properties and was for this reason included for a time in cosmetic formulations. However, when given topically it caused photosensitivity reactions, and this form of application has been abandoned. 

Flutamide can cause photosensitivity reactions (18-20) and can cause residual vitUigo (21,22). The spectrum of the effect is in the UVA range (23). 

Urticaria, fixed drug eruptions (131,134-137), erythema nodosum (138), photosensitivity reactions (139), and generalized skin reactions involving light-exposed areas (139-141) are less common. Topical silver sulfadiazine cause local reactions, consisting of rash, pruritus, or a burning sensation in 2.5% of patients (4,51). 

Triamterene has been reported to cause photosensitivity reactions, increase in uric acid concentration, and blood dyscrasias.91 Nephrolithiasis may occur in susceptible patients. Megaloblastic anemia has been reported in patients with depleted folic acid stores such as those with hepatic cirrhosis. In a study conducted on rats, daily treatment of the animals with doses of 1.5, 3 and 4.5 mg/lOOg over the period of three weeks caused severe degenerative changes of renal cortical and medullary tubules resembling osmotic nephrosis.93 Reversible acute renal failure from combined triamterene and indomethacin in healthy subjects is reported.94 It is recommended that this potentially nephrotoxic association be avoided. 

Catalyst instability can be a problem that may be tackled by developing an immobihzed catalyst. Organic catalysts do exist that slowly decompose under the condihons necessary for their reaction and release trace amounts of byproducts hiat must be separated from the products. For example, in photooxygenahon reachons catalyzed by porphyrin the release of highly colored materials derived from the photosensitizer may cause major problems with the product purificahon. By immobilizing the catalyst this problem can be solved because the decomposed materials are also supported and can be removed from the reachon medium during the work-up process. 

Reactive species formed by the CDOM absorption of UVR can then undergo indirect, or secondary, photochemical reactions. In fact, the many possible reactions caused by photosensitized transient intermediates probably account for most of the photodegradation of CDOM that we observe. The many different photoprocesses involved in CDOM photochemistry make for a very complex pathway of reactions beginning with the initial absorption of light energy and ending with the final products of these multiple reactions. 

It is believed that phototoxicity causes cellular damage by direct modification of certain target molecules, such as DNA, lipids, and/or amino acids and proteins. In principle, this can occur by the photosensitization reactions described earlier, and there is a reasonable correlation between the capacity of a drug to participate in type I and type II processes in vitro and the number of adverse photosensitivity reports registered against them. It is, of course, difficult to compare different drugs in this way because a number of extra variables enter — for example, the dose and pharmacokinetics of the drug s biodistribution. 

Like other diuretics, thiazides can induce hypokalemia, hyponatremia, hypochloiemia. hypomagnesemia. hypercalcemia, hyperuricemia, glucose intolerance, dehydration, and changes in the lipid profile. Thiazides may also cause photosensitivity reactions. 

The naphthalene derivatives apparently acted as photosensitizers which caused an increase in solubilization of the films through a reaction mechanism involving the formation of peroxides and alcohols. A case was made for the addition of photosensitizers to oil spills at sea to accelerate their removal by sunlight photo-oxidation, but in view of the observed toxicity of photoproducts from oil layer degradation towards aquatic microorganisms (Lacaze and Villedon, 1976 Larson et al., 1977), this approach warrants careful consideration. The use of chemical dispersants was found to magnify the toxicity by a factor of at least 10—15 (Lacaze and Villedon,... 

Gastrointestinal reactions that may occur during tetracycline administration include nausea, vomiting, diarrhea, epigastric distress, stomatitis, and sore throat. Skin rashes also may be seen. A photosensitivity (phototoxic) reaction may be seen witli tliis group of dni, manifested by an exa rated sunburn reaction when the skin is exposed to sunlight even for brief periods. Demeclocychne seems to cause the most serious photosensitivity reaction, whereas minocycline is least likely to cause this type of reaction. 

The furanocoumarins, psoralen, bergapten, xanthotoxin and isopimpinellin, were detected in celery leaves and stalk. The total furanocoumarin content ranged from about 12 to 50 mg/kg in Florida cultivars [54]. Treatment with fungicides increased the bergapten content 2-4 times in leaves and stalk, xanthotoxin 2-3 times in stalk, and isopimpinellin about 2-3 times in leaves, while psoralen levels remained constant. This fact is of some importance since linear furanocoumarins are the cause of photosensitive reactions in humans. 

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