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By William T. Elliott, MD, FACP
Statins appear to decrease the incidence of Alzheimer’s disease (AD) according to 2 recent retrospective studies from Germany. Statins have been shown to cross the blood-brain barrier and inhibit de novo cholesterol synthesis in the brain. This may explain why statins appear to be more effective in preventing AD than other types of cholesterol-lowering medications such as fibrates, resin binders, or nicotinic acid, which do not cross the blood- brain barrier. Statins may reduce endogenous cholesterol in the brain, but they also seem to modulate the deposition of A-beta-amyloid peptide which is believed to be an early step in the development of fibril formation. This study raises intriguing questions, which need to be further studied, according to Simons and colleagues (Simons M, et al. Neurology. 2001;57:1089-1093).
Pneumococcal resistance to macrolide antibiotics including erythromycin, clarithromycin, and azithromycin, nearly doubled between 1995 and 1999 according to a report from the CDC. In 1995, 10.6% of isolates were fully resistant to macrolides, with the percentage increasing to 20.4% by 1999. This occurred as macrolide use increased, especially among children. Currently, many treatment guidelines recommend macrolides as first-line agents for community-acquired pneumonia. Hyde and associates suggest that other agents may now need to be considered first line (Hyde TB, et al. JAMA. 2001;286:1857-1862).
"First generation" antibiotics amoxicllin, erythromycin, and trimethoprim-sulfamethoxazole are as effective as newer antibiotics at treating acute sinusitis according to a new study. The patient data were drawn retrospectively from more than 29,000 HMO patients. Nearly 60% received a first-generation antibiotic for a diagnosis of sinusitis while 40% received 1 of 14 "second-generation" antibiotics, generally broad-spectrum antibiotics such as second- or third-generation cephalosporins or extended-spectrum penicillins. Regardless of the drug chosen, the success rate was just over 90% after 28 days. The only significant difference was the cost of care, being significantly higher with second-generation antibiotics (Piccirillo JF, et al. JAMA. 2001;286:1849-1856).
Reduction of blood pressure, regardless of the antihypertensive agent chosen, is the most important factor in reducing the risk of cardiovascular events. Staessen and colleagues, in this large meta-analysis of 9 clinical trials involving more than 62,000 patients, sought to establish whether certain antihypertensive agents had cardioprotective properties beyond their blood pressure lowering effects. Calcium channel blockers were found to offer more reduction in the risk of stroke, but less effective at reducing the risk of myocardial infarction. Otherwise, all antihypertensive agents including older agents such as diuretics and beta blockers offered the same benefit as newer agents such as calcium channel blockers and ACE inhibitors, and the newer agents offered no benefit beyond their blood pressure lowering effect (Staessen JA, et al. Lancet. 2001;358:1305-1310).
The recent anthrax exposures and illnesses have made "Cipro" a household word, creating more name recognition than the marketing department at Bayer could ever conceive. Although penicillin and doxycycline are also approved for the treatment of anthrax, "Cipro" has been getting all the press. Now Johnson and Johnson, the makers of levofloxacin (Levaquin) are seeking an indication for the treatment of anthrax also. The company has supplied the FDA with in vitro data showing activity against anthrax, as well as data demonstrating superior lung penetration compared to other quinolones. To its credit, Johnson and Johnson is prepared to donate 100 million tablets of levofloxacin to the government for dispersal to the general population should it become necessary. Meanwhile GlaxoSmithKline, which makes amoxicillin and Augmentin, says they are ready to ramp up production of their antibiotics if they should be needed. Neither drug has an indication to treat anthrax, but the company says both drugs are very effective against Bacillus anthracis.
Estrogen replacement has been found to be ineffective in the role of secondary prevention after myocardial infarction. (Please see article on page 30). Now a new study shows that estrogen replacement is similarly ineffective for secondary prevention of stroke. A randomized, double blind, placebo-controlled trial was done on 664 women who had suffered a stroke or TIA. They were randomized to 1 mg/d of estradiol or placebo. After a mean follow-up of 2.8 years there were 99 strokes or deaths in the estradiol group and 93 in the placebo group. The risk of death, rate of stroke, and the severity of nonfatal stroke were all worse in the estrogen group. Viscoli and associates conclude that estrogen replacement should not be prescribed for the secondary prevention of cerebrovascular disease (Viscoli CM, et al. N Engl J Med. 2001;345:1243-1249).