SUMMARYClioquinol was produced as a topical antiseptic and marketed as an oral intestinal amebicide in 1934, being used to treat a wide range of intestinal diseases. In the early 1970s, it was withdrawn from the market as an oral agent because of its association with subacute myelooptic neuropathy (SMON), a syndrome that involves sensory and motor disturbances in the lower limbs and visual changes. The first methods for determining plasma and tissue clioquinol (5-chloro-7-iodo-8-quinolinol) levels were set up in the 1970s and involved HPLC separation with UV detection, these were followed by a more sensitive GC method with electron capture detection and a gaschromatographic-massspectrometric (GC-MS) method. Finally, an HPLC method using electrochemical detection has proved to be as highly sensitive and specific as the GC-MS. In rats, mice, rabbits, and hamsters, clioquinol is rapidily absorbed and undergoes first-pass metabolization to glucuronate and sulfate conjugates; the concentrations of the metabolites are higher than those of free clioquinol. Bioavailabilty versus intraperitoneal dosingis about 12%. Dogs and monkeys form fewer conjugates. In man, single-dose concentrations are dose related, and the drug's half-life is 11-14 h. There is no accumulation, and the drug is much less metabolized to conjugates. Clioquinol acts as a zinc and copper chelator. Metal chelation is a potential therapeutic strategy for Alzheimer's disease (AD) because zinc and copper are involved in the deposition and stabilization of amyloid plaques, and chelating agents can dissolve amyloid deposits in vitro and in vivo. In general, the ability of clioquinol to chelate and redistribute metals plays an important role in diseases characterised by Zn, Cu, Fe dyshomeostasis, such as AD and Parkinson's disease, as it reduces oxidation and the amyloid burden. Zinc chelators may also act as anticancer agents. Animal toxicity studies have revealed species-specific differences in neurotoxic responses that are related to the serum levels of clioquinol and metabolites. This is also true in humans, who form fewer conjugates. The results of studies of Alzheimer patients are conflicting and need further confirmation. The potential therapeutic role of the two main effects of MPACs (the regulation of the distribution of metals and antioxidants) has not yet been fully explored.

Most antioxidants show contradictory behaviors because in the biological environment, for unpredictable reasons, they can become prooxidants. Recently, a new simple method to monitor oxidative stress in serum was developed. This test detects the derivatives of reactive oxygen metabolites (D-Roms). Hydroperoxides are converted into radicals that oxidize N,N-diethyl-para-phenylendiamine and that can be detected through spectrophotometric procedures as U.CARR. (Carratelli units). One U.CARR. corresponds to 0.8 mg/L hydrogen peroxide. In normal subjects U.CARR. values range from 250 to 300. Values outside this range indicate a modification of the prooxidant/antioxidant ratio. On the basis of this method, we tested three different formulas of antioxidants (F1, F2, F3) in 14 apparently healthy volunteers (11 men and 3 women). Formula 1 was composed of 5 mg zinc, 48 microg selenium, 400 microg vitamin A (as retinol acetate), 50 microg beta-carotene, 15 mg vitamin E (as dl-alpha-tocopheryl acetate) and 10 mg L-cysteine. Formula 2 was composed of 30 mg bioflavonoids from citrus, 30 mg vitamin C (as L-ascorbic acid), 10 mg coenzyme Q(10) and 1 mg vitamin B-6 (as pyridoxine hydrochloride). Formula 3 was composed of Formula 1 plus Formula 2. Each formula was prepared in dry capsules (formulation D1, D2, D3) or in a fluid form (formulation P1, P2, P3). Each formulation was administered for 1 wk in a crossover design. A 15% deviation of U.CARR. levels was chosen as the cut-off value for a significant change in oxidative stress. Formulas F1 and F3 reduced mean U.CARR. levels in most of the treated subjects (t test, P < 0.05), whereas F2 was not active. Fluid formulations were more active than dry formulations (chi(2) test, P < 0.05). In some cases, a slight increase in oxidative stress was detected. These minimal increases were not related to any particular antioxidant formula. In one subject only, the administration of the dry formulation (D1), increased oxidative stress to a level that reached the cut-off value. In conclusion, when antioxidants are taken in combination at low dosages they reduce oxidative stress, and little relevant prooxidant activity is detectable.

The study compared, by a prospective, randomized method, 6 treatment options: A: Sclerotherapy; B: High-dose sclerotherapy; C: Multiple ligations; D: Stab avulsion; E: Foam-sclerotherapy; F: Surgery (ligation) followed by sclerotherapy. Results were analyzed 10 years after inclusion and initial treatment. Endpoints of the study were variations in ambulatory venous pressure (AVP), refilling time (RT), presence of duplex-reflux, and number of recurrent or new incompetent venous sites. The number of patients, limbs, and treated venous segments were comparable in the 6 treatment groups, also comparable for age and sex distribution. The occurrence of new varicose veins at 5 years varied from 34% for group F (surgery + sclero) and ligation (C) to 44% for the foam + sclero group (E) and 48% for group A (dose 1 sclero). At 10 years the occurrence of new veins varied from 37% in F to 56% in A. At inclusion AVP was comparable in the different groups. At 10 years the decrease in AVP and the increase in RT (indicating decrease in reflux), was generally comparable in the different groups. Also at 10 years the number of new points of major incompetence was comparable in all treatment groups. These results indicate that, when correctly performed, all treatments may be similarly effective. "Standard," low-dose sclerotherapy appears to be less effective than high-dose sclero and foam-sclerotherapy which may obtain, in selected subjects, results comparable to surgery.

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Superficial vein thrombosis is characterized by clotting of superficial veins (ie, following direct trauma) with minimal inflammatory components. Superficial thrombophlebitis is a minimally thrombotic process of superficial veins associated with inflammatory changes and/or infection. Treatments generally include analgesics, elastic compression, anti-inflammatory agents, exercise and ambulation, and, in some cases, local or systemic anticoagulants. It is better to avoid bed rest and reduced mobility. Topical analgesia with nonsteroidal, anti-inflammatory creams applied locally to the superficial vein thrombosis/superficial thrombophlebitis area controls symptoms. Hirudoid cream (heparinoid) shortens the duration of signs/symptoms. Locally acting anticoagulants/antithrombotics (Viatromb, Lipohep, spray Na-heparin) have positive effects on pain and on the reduction in thrombus size. Intravenous catheters should be changed every 24 to 48 hours (depending on venous flow and clinical parameters) to prevent superficial vein thrombosis/superficial thrombophlebitis and removed in case of events. Low molecular weight heparin prophylaxis and nitroglycerin patches distal to peripheral lines may reduce the incidence of superficial vein thrombosis/superficial thrombophlebitis in patients with vein catheters. In case of superficial vein thrombosis/superficial thrombophlebitis, vein lines should be removed. In neoplastic diseases and hematological disorders, anticoagulants may be necessary. Exercise reduces pain and the possibility of deep vein thrombosis. Only in cases in which pain is very severe is bed rest necessary. Deep vein thrombosis prophylaxis should be established in patients with reduced mobility. Antibiotics usually do not have a place in superficial vein thrombosis/superficial thrombophlebitis unless there are documented infections. Prevention of superficial vein thrombosis should be considered on the basis of patient's history and clinical evaluation.