Retinopathy induced by drugs and herbal medicines.

Retina is the part of the eye suffering most damage from drugs. It is made up of a thin nervous membrane that covers the eye-ball internally, within the thickness of which three types of cells are ordered. In this paper we describe the drugs that are responsible for retinal side effects. Most commonly recognized drugs-induced retinopathy have a particular affinity for the retinal pigmented epithelium: antimalarials (quinine, hydroxychloroquine, mefloquine), phenothiazines, indomethacin, ethambutol, and desferrioxamine. Attention is especially focused on drugs more recently suspected of adverse reactions in the retina: vigabatrin, gabapentin, sildenafil, tamoxifen, isotretinoin, interferon, and omeprazole. Moreover, we referred some reports of retinopathy by herbal medicines and nutritional supplements (canthaxanthine, Gingko biloba L. and Glycyrrhiza glabra L.) This review is based on data published in scientific journals indexed by the PubMed and Medline databases. The last search of the literature was conducted in April 2008.

Effect of acetaminophen on glutathione levels in rat testis and lung.

Glutathione (GSH) levels in rat testis and lung after oral administration (3 g/kg) of acetaminophen (APAP) were studied. At the administered dose APAP is present in each organ and influences the GSH levels. APAP value of 114 micrograms/g was obtained in testis at 6 hr (peak time); in the lung the Cmax was 92 mu/g at 8 hr and this value lasted several hours longer than that in testis. GSH levels are also affected differently in the organs studied after APAP administration; the lungs seem to be the primary organ undergoing the depleting action of APAP. This process could not only cause toxicity, but also predispose those organs to the action of toxic compounds responsible for specific pathologies.

Inhibition of ornithine-decarboxylase produced by S(+) and R(-) ibuprofen in rats.

The differences between the S(+) and R(-) ibuprofen enantiomers in anti-inflammatory activity were assayed by measuring the release of 14CO2 in rats treated with labelled 14COOH-ornithine. Furthermore we investigated in vitro the inhibitory activity on ornithine-decarboxylase and the anti-inflammatory activity of R(-) and S(+) ibuprofen by using the carrageenin-induced paw oedema test in the rat.

Synthesis and antiinflammatory/analgesic activities of N-heterocyclic carboxamides of thiopyrano-1,2-benzothiazine.

We report the synthesis of N-heterocyclic carboxamides of 5-methyl-4-oxo-2,3,4,5-tetrahydrothiopyrano [3,2-c][1,2]benzothiazine 6,6-dioxide, their antiinflammatory and analgesic activities and the attempts to obtain a corresponding sulfoxidate series. Compounds (II c) and (II l) showed a good antiinflammatory activity which is comparable to that of piroxicam. No compound showed any significant analgesic activity.

Kinetics of amiloride in rat following oral and intravenous administration.

The disposition profile of amiloride, a potassium sparing agent, was studied in rats by using an HPLC method coupled to spectrofluorometric detection. Amiloride was administered orally and intravenously at the dose of 10 mg/Kg. The most relevant pharmacokinetic parameters are described for both administration routes.

Effect of buspirone on glutathione hepatic levels in rat.

The effect of oral administration of buspirone (0.5-1.0 and 2.0 mg/Kg) on GSH levels was studied in rat liver. The modulating activity of buspirone on hepatic content of this tripeptide is clearly opposite to that of DAZ, put into evidence by us in previous works. Thus our observations let us hypothesize a different mechanism of action for buspirone than that for benzodiazepines.

The kinetics in the rat of a new nitroimidazole derivative.

A new nitroimidazole derivative, N-(5-carboxy-5-amino pentane) carbamic ester of 1(2-hydroxyethyl)-2-methyl-5-nitroimidazole (APMN), was administered to rats by the following routes: i.p. and orally (100 mg/kg); i.m. (100 and 250 mg/kg). Plasma kinetics of the drug fit a monoexponential function with a half-life of 0.5 h and a volume of distribution of 555 ml/kg. In tissues the peak levels of the drug (at 0.5 h) were 700, 150 and 40 micrograms/g in kidney, liver and heart respectively and their disappearance rate was similar to that observed for plasma. Urinary excretion of the unmodified drug in 23 h was less than 30% of the administered dose. No APMN was found in plasma and urine after oral administration.