(3S-5S-6E)-7-[3-(4-fluorophenyl)-1-(propan-2-yl)-1H-indol-2-yl]-3-5-dihydroxyhept-6-enoic-acid and Cataract

Statins are regarded as a well-tolerated class of drugs, particularly when compared with some of the older lipid-modifying agents, which have poor rates of compliance. Despite some early concern, the incidence of lens opacities observed in clinical studies involving statin use is no different from that in a normal ageing population. Similarly, the occurrence of insomnia with lipophilic agents appears to have been overemphasised and is not a clinically significant problem, irrespective of the statin under study. Fluvastatin is the newest representative of this class of agents; it has already been evaluated in thousands of patients who have hyperlipidaemia with and without additional risk factors. In controlled clinical studies, the incidence of the majority of adverse events observed with fluvastatin therapy is no higher than that seen with placebo, with the exception of gastrointestinal disturbances (known to be common to all stains). Nonetheless, the incidence of these effects seen with fluvastatin treatment is noted to be lower than that associated with cholestyramine or fibrate use. Elevations in levels of liver transaminases (aspartate aminotransferase and alanine aminotransferase) have been reported with fluvastatin therapy but have led to discontinuation of treatment with the same frequency as with placebo. Elevations in creatine kinase levels as a cause of discontinuing fluvastatin are not more frequent than with placebo. Drug-related myopathy and rhabdomyolysis have not been reported with fluvastatin therapy, and myalgia does not occur more frequently than with placebo. In terms of drug interactions, fluvastatin does not interfere with the efficacy of antihypertensive agents. In controlled clinical trials, the overall reported discontinuation rate due to adverse events noted with fluvastatin therapy is not significantly distinguishable from the rate associated with placebo.

Topics: Adult; Aged; Anticholesteremic Agents; Cataract; Fatty Acids, Monounsaturated; Fluvastatin; Humans; Indoles; Middle Aged; Prospective Studies; Randomized Controlled Trials as Topic; Risk Factors

Fluvastatin is a potent synthetic competitive inhibitor of beta-hydroxy-beta-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in the biosynthetic pathway for hepatic cholesterol synthesis. The therapeutic indication is reduction of elevated total and low-density lipoprotein cholesterol levels. Results from four toxicity studies in beagle dogs and one study in rhesus monkeys following oral administration of fluvastatin are reported. In two 26-week dog studies, doses were 0, 1, 8, or 48 mg/kg/day (reduced to 36 mg/kg/day in Week 7) and 0, 6, 24, or 36 mg/kg/day (reduced to 30 mg/kg/day in Week 2). In a 2-year dog study, doses were 0, 1, 8, or 16 mg/kg/day. Dose levels in the 26-week monkey study were 0, 0.6, 12, and 48 mg/kg/day (raised to 84 mg/kg/day in Week 17 and to 108 mg/kg/day in Week 22). In these studies, evaluations included clinical and physical examinations, body weight and food consumption, electrocardiography, ophthalmoscopy, hematology and clinical chemistries, urinalysis, blood drug concentration, and macroscopic and microscopic examinations of observed lesions and representative tissues. In the 26- and 52-week dog studies and the monkey study, lenticular biochemistry, the HMG-CoA reductase activity of liver microsomes, and serum lipid concentrations were investigated. The fourth dog study was a single-dose toxicokinetic study in which 48 mg/kg [3H]-fluvastatin was monitored for up to 2 weeks. Sampling was limited to ocular tissues for enzyme analysis. Doses of > or = 24 mg/kg/day were lethal in dogs. At lethal doses, ataxia, convulsions, fecal blood, multifocal congestion and hemorrhage, isolated foci of malacia in the medulla oblongata, and liver necrosis were observed. Reduced weight gain, emesis, cataracts, elevated liver enzymes, reduced cholesterol, and gallbladder inflammation with mucosal hyperplasia occurred at > or = 8 mg/kg/day. In contrast to other HMG-CoA reductase inhibitors, fluvastatin did not cause significant central nervous system hemorrhage or testicular changes in dogs. Monkeys tolerated exposure to fluvastatin well with only mild gallbladder changes observed. Reduced serum cholesterol and slight hyperplasia of the gallbladder mucosa occurred in the 12 and 48/84/108 mg/kg/day groups.

Topics: Administration, Oral; Animals; Body Weight; Cataract; Dogs; Eating; Fatty Acids, Monounsaturated; Female; Fluvastatin; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Indoles; Lens, Crystalline; Lipids; Liver; Macaca mulatta; Male; Microsomes, Liver; Time Factors

Post-mortem biochemical analyses of dog lenses and of aqueous humour of a 2 year oral toxicity study in the dog with Fluvastatin (control, 1, 8 and 16 mg/kg/day) did not show any relationship to the observed lens opacities (3 animals out of 8 at 16 mg/kg/day). With respect to lens transparency, a daily dosage of 8 mg/kg/day Fluvastatin to dogs over a period of 2 years is non-cataractogenic. Mean data on lenticular enzyme activities (GPX, G6PH, GAPDH, ALD, AR, LDH, PFK and SDH) as well as measurements of GSH/GSSG, ATP, ADP, AMP, Gluc, Fruc, Sorb, G6P and F6P do not indicate changes which may directly lead to lens opacifications. Conformational changes of lens proteins (heat lability of PFK-activity), a shift in the albumin/IgG ratio of aqueous humour and equatorial lens protein composition changes (after isoelectrofocusing) were observed. The biological significance of these changes is unknown as the non-cataractogenic dose for lens opacities in beagle dogs is 8 mg/kg/day.

Topics: Animals; Anticholesteremic Agents; Aqueous Humor; Cataract; Crystallins; Dogs; Enzymes; Eye Proteins; Fatty Acids, Monounsaturated; Female; Fluvastatin; Glutathione; Glycolysis; Indoles; Lens, Crystalline; Male; Phosphofructokinase-1