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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors give a study about retinopathy by 4-amino-quinoleine in malaria prevention. Twelve observations are known in patients after 12 to 20 years of treatment. The authors suggest systematic research of this retinopathy.
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PMID:[Retinopathy due to 4-aminoquinolines in the prevention of malaria]. 53 15

Capillary permeability was investigated in 32 Thai patients aged 14-49 years who had acute falciparum malaria with use of three distinct techniques: quantitation of the urinary albumin/creatinine ratio (ACR), estimation of the transcapillary escape rate of radiolabeled albumin (TER), and retinal photography/fluorescein angiography. Fourteen patients had uncomplicated infections and 18 were severe cases. The severely ill patients had significantly higher ACRs (median, 4.8 mg/mmol; 95% confidence limits, 2.4-19.9 mg/mmol) and TERs (median, 8.3%/h; 95% confidence limits, 6.2-13.2%/h) than the uncomplicated cases (ACR: median, 2.1 mg/mmol; 95% confidence limits, 6.2-13.2%/h) than the uncomplicated cases (ACR: median, 2.1 mg/mmol; 95% confidence limits, 1.0-8.8 mg/mmol; TER: median, 5.9%/h; 95% confidence limits, 3.8-10.6%/h; P = .014 and .042). Both variables were significantly associated with biochemical indices of disease severity including total serum bilirubin levels (rs greater than or equal to 0.398, P less than .025 in each case), but there were no significant differences between ACRs and TERs among comatose and noncomatose patients with severe infections (P greater than or equal to .08). Retinopathy (hemorrhages, cotton-wool spots, capillary nonperfusion, and/or extravasation of fluorescein) was found in eight severely ill patients and in two uncomplicated cases. Fluorescein leakage was evident in six patients. Although fluorescein leakage had the strongest parametric correlation with the presence of coma relative to both ACR and TER in the full patient series (r = 0.58, P less than .01), multiple linear regression analysis indicated that concentrations of plasma lactate (t = 2.998, P = .006) and serum creatinine (t = 2.200, P = .036) were the factors responsible for this association. These data do not support a role for tissue edema in the pathogenesis of cerebral malaria but reveal an association between markers of disease severity and a generalized increase in systemic capillary permeability.
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PMID:Measures of capillary permeability in acute falciparum malaria: relation to severity of infection and treatment. 152 Jul 60

The antimalarials, chloroquine, hydroxychloroquine, and quinacrine, are used primarily for malaria; but they can be beneficial for cutaneous lupus erythematosus (LE), polymorphous light eruption, solar urticaria, and porphyria cutanea tarda. Antimalarials bind to deoxyribonucleic acid (DNA) which prevents DNA and ribonucleic acid (RNA) polymerase reactions and DNA heat inactivation; and they inhibit the LE cell phenomenon, antinuclear antibody reactions, and suppress lymphocyte transformation. By competing with calcium ion, they stabilize membranes and have an anesthetic effect. Their anti-inflammatory potential is due to their inhibition of hydrolytic enzymes, stabilization of lysosomes, interference with prostaglandin synthesis, blocking of chemotaxis, and antagonism of histamine responses. The antimalarials have no sunscreening properties. The most common toxic effects are cutaneous pigmentation, nausea, vomiting, diarrhea, mild ileus, and cycloplegia. There has been a reluctance to use chloroquine and hydroxychloroquine because of the possibility of retinopathy. However, if the "safe" daily dose limit of chloroquine, 2 mg per pound of body weight, and of hydroxychloroquine, 3.5 mg per pound of body weight, is followed, the chance of retinopathy is slight. Quinacrine does not cause retinopathy, but it has more cutaneous side effects than the other two agents.
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PMID:Antimalarials. 616 44

A 16-year old girl with insulin-dependent diabetes mellitus (8 years' duration) developed tropic malaria 7 weeks after her return from Kenya despite a longtime prophylaxis using pyrimethamine and sulfadoxine (Fansidar). The disease was detected during an episode of ketoacidosis which proved exceptionally difficult to manage. Adequate chloroquine therapy resulted in temporary recovery. A recurrence of malaria four weeks later was successfully treated with quinine and doxycycline. Intraleucocytary parasites were found during both these episodes. Already prior to antimalarial drug therapy the girls' preexisting retinopathy was found to have deteriorated.
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PMID:[Chloroquine and pyrimethamine/sulfadoxine resistant malaria tropica in a child with diabetes mellitus]. 637 25

The sensitivity of Plasmodium falciparum strains to chloroquine was tested in one locality in the north-east of the United Republic of Tanzania, where a chloroquine-medicated salt project has been implemented for chemosuppression for many years, and where large amounts of the drug have been available during the last decade for the treatment of malaria infections.Single doses of chloroquine (5 or 10 mg of base/kg of body weight) failed to clear P. falciparum trophozoites in asymptomatic parasite carriers selected from the school population. In comparison, clearance had been obtained easily ten years previously with 5 mg of base/kg of body weight in several localities in the area.A total dose of 25 mg of base/kg of body weight given over a 3-day period succeeded in clearing asexual parasites from the peripheral blood by day 3 in all instances. Asexual parasites were not found again during the nine days following administration of the drug.All the schoolchildren who had received 5 or 10 mg of base/kg of body weight at the beginning of the trial were treated with a further 20 mg of base/kg of body weight at the end of the 7-day observation period. Asexual parasites reappeared in the blood of some of these children 7-10 days after the second administration of the drug.Using the in vitro microtechnique, incomplete schizont inhibition was observed in 3 out of 21 cases at a chloroquine concentration of 1.14 mumol/litre of blood, which is the discriminating dosage for resistance at RI level.No cases of retinopathy related to the prolonged use of chloroquine were detected among the 221 residents who had spent more than 16 consecutive years in the locality.
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PMID:Incipient resistance of Plasmodium falciparum to chloroquine among a semi-immune population of the United Republic of Tanzania. 1. Results of in vivo and in vitro studies and of an ophthalmological survey. 704 90

Chloroquine continues to have a limited role in the chemoprophylaxis against malaria. Although periodic ophthalmologic examinations are recommended with weekly suppressive dosing, the occurrence of retinopathy associated with this regimen is unproven. Surveillance of career missionaries was conducted to explore the association between total body burden of chloroquine and the development of retinopathy. Five hundred eighty-eight missionaries, reflecting 6,250 person-years of chloroquine exposure were surveyed; 53 persons reflecting 560 person-years exposure with a median cumulative chloroquine dose in excess of 300 g were examined. Only one case of chloroquine-induced retinopathy was detected. This occurred in a missionary who had inappropriately taken chloroquine daily for at least six years as an anti-inflammatory agent for a connective tissue disorder. We also observed that expatriates often overused chloroquine because of apprehension about malaria and used the drug for unrelated conditions. Our results failed to demonstrate an association between a weekly chloroquine dosing regimen and drug-induced retinopathy.
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PMID:No evidence for chloroquine-associated retinopathy among missionaries on long-term malaria chemoprophylaxis. 794 62

Contracting malaria, especially Plasmodium falciparum infection, remains one of the main risks when non-immunes travel to the tropics. This contribution tries to describe qualitatively, and, wherever possible, quantitatively, the risk to suffer death or permanent incapacitation due to prophylaxis, disease or therapy of malaria. Roughly three million Germans annually go for a three to four weeks' trip to malaria-endemic areas. Around 700 to 1000 of them fall ill with malaria, two thirds infected with Pl. falciparum. Grossly 2% of patients expire. Lasting physical damage due to malaria (neurological sequelae after cerebral malaria, splenic rupture, impaired vision) due to therapy (cardiac side effects of chloroquine, quinine and mefloquine, acute psychoses) or due to prophylaxis (retinopathy after long-term chloroquine) are uncommon and hard to quantify. On the whole, however, well-tailored, correctly dosed prophylaxis, early diagnosis and circumspect therapy lower the risk of suffering grave health impairment due to malaria.
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PMID:[Chronic morbidity after travel in endemic malaria regions]. 812 48

Most drugs used in the treatment of malaria produce phototoxic side effects in both the skin and the eye. Cutaneous and ocular effects that may be caused by light include changes in skin pigmentation, corneal opacity, cataract formation and other visual disturbances including irreversible retinal damage (retinopathy) leading to blindness. The mechanism for these reactions in humans is unknown. We irradiated a number of antimalarial drugs (amodiaquine, chloroquine, hydroxychloroquine, mefloquine, primaquine and quinacrine) with light (lambda > 300 nm) and conducted electron paramagnetic resonance (EPR) and laser flash photolysis studies to determine the possible active intermediates produced. Each antimalarial drug produced at least one EPR adduct with the spin-trap 5,5-dimethyl-1-pyrroline N-oxide in benzene: superoxide/hydroperoxyl adducts (chloroquine, mefloquine, quinacrine, amodiaquine and quinine), carbon-centered radical adducts (all but primaquine), or a nitrogen-centered radical adduct only (primaquine). In ethanol all drugs except primaquine produced some superoxide/hydroperoxyl adduct, with quinine, quinacrine, and hydroxychloroquine also producing the ethoxyl adduct. As detected with flash photolysis and steady-state techniques, mefloquine, quinine, amodiquine and a photoproduct of quinacrine produced singlet oxygen ([symbol: see text]delta = 0.38; [symbol: see text]delta = 0.36; [symbol: see text]delta = 0.011; [symbol: see text]delta = 0.013 in D2O, pD7), but only primaquine quenched singlet oxygen efficiently (2.6 x 10(8) M-1 s-1 in D2O, pD7). Because malaria is a disease most prevalent in regions of high light intensity, protective measures (clothing, sunblock, sunglasses or eye wraps) should be recommended when administering antimalarial drugs.
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PMID:Photophysical studies on antimalarial drugs. 1008 18

Chloroquine and its derivative, hydroxychloroquine sulfate, have been used in treating malaria, dermatitides of systemic lupus erythematosus and rheumatoid arthritis. Hydroxychloroquine retinopathy is uncommon in Taiwan. Here we report a patient with hydroxychloroquine retinopathy which progressed even after discontinuation of hydroxychloroquine. A 42-year-old woman had systemic lupus erythematosus for twenty years. She had been treated with 200 to 400 mg of hydroxychloroquine per day (4 to 8 mg/kg of body weight/day) with a cumulative dose of 657 g. After bull's-eye maculopathy was found, hydroxychloroquine was discontinued. Her medical history revealed no chloroquine administration and no other systemic disease. Five years after cessation of the therapy, her visual acuity and visual fields continued to deteriorate. Ophthalmoscopic examination revealed the hydroxychloroquine retinopathy had advanced. To the best of our knowledge, the progression of hydroxychloroquine retinopathy after discontinuation of medications is a rare phenomenon. Regular ophthalmologic examinations should be performed for patients on hydroxychloroquine regimens because there is no satisfactory treatment for hydroxychloroquine retinal toxicity. Ophthalmologists, dermatologists and rheumatologists should monitor for ocular toxicity of hydroxychloroquine carefully.
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PMID:Progression of hydroxychloroquine retinopathy after discontinuation of therapy: case report. 1148 Mar 31

Chloroquine retinopathy (CR) is a major complication of long-term malaria prophylaxis (LTMP) causing permanent visual dysfunction and occasionally blindness. After an extensive review of the published accounts of CR, we concluded that the risk of retinopathy in subjects receiving LTMP is limited to a cumulative dose that does not exceed 140 g. We present a case of CR that occurred after 8 years of malaria prophylaxis with chloroquine at a cumulative dose of 125 g. Because a threshold dose of chloroquine for retinal toxicity has not been established, careful, ongoing screening is required, especially as the cumulative dose increases.
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PMID:Case report: Retinopathy after malaria prophylaxis with chloroquine. 1171 27


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