Benzodiazepines still being overprescribed
Despite evidence that benzodiazepines increase the risk of falls, these central nervous system depressants are still being overprescribed to older adults at risk for falling. Canadian researchers who followed more than 250,000 older adults for 5 years found that those who already had some risk factors for falling were actually more likely to be prescribed a benzodiazepine than those with no risk factors. For example, depression and antidepressant drugs both increase an older adult's fall risk. Yet patients with depression were 42% more likely than those without depression to be prescribed a benzodiazepine. These drugs were also prescribed more frequently to older adults with arthritis or alcohol abuse issues, which also increase the risk of falling.
Researchers say their findings highlight an important medication safety issue. Teach patients to always ask their prescriber why they need a benzodiazepine (or any drug they're taking), how long they should take it, and how they can safely stop taking it.
Source: Bartlett G, Abrahamowicz M, Grad R, et al. Association between risk factors for injurious falls and new benzodiazepine prescribing in elderly persons. BMC Fam Pract. 2009;10:1.
New treatment for chronic anemia
Ferumoxytol, an I.V. form of iron that allows large doses to be given rapidly, has proven effective for treating anemia in patients with chronic kidney disease (CKD) who need hemodialysis. A clinical trial enrolled 230 anemic patients with late-stage CKD who were on hemodialysis. Patients received either two injections of 510 mg ferumoxytol within 7 days, or 200 mg oral iron daily for 21 days. Researchers measured hemoglobin changes in patients for 35 days from the trial's start.
The two doses of ferumoxytol caused significantly greater hemoglobin increases than treatment with oral iron. Those who took ferumoxytol had an average of 1.02 g/dL increase in hemoglobin at day 35, compared with an increase of only 0.46 g/dL with oral iron. Adverse reaction rates were comparable between groups.
Source: Provenzano R, Schiller B, Rao M, Coyne D, Brenner L, Pereira BJG. Ferumoxytol as an intravenous iron replacement therapy in hemodialysis patients. Clin J Am Soc Nephrol. 2009; 4:386-393.
Vaccine protects both kids and older adults
The pediatric pneumococcal conjugate vaccine (PCV7), which was introduced in 2000, seems to have reduced rates of pneumococcal meningitis in both children and adults, based on a review of 1,379 cases of pneumococcal meningitis from 1998 to 2005. However, researchers noted an increase in strains of pneumococcal meningitis not covered by the vaccine and in antibiotic-resistant strains.
After the vaccine was introduced, rates of pneumococcal meningitis dropped by 64% in children and 54% in older adults. But strains of disease not covered by the PCV7 vaccine increased during the study period by 61%. Strains not sensitive to penicillin increased from 19% in 2003 to 30% in 2005.
Researchers say their findings indicate that the vaccine's success has been "substantial," but that the recent increase in meningitis caused by strains that aren't covered by the vaccine and those that are drug resistant is "a concern." One of the study authors, Lee Harrison, MD, notes that new vaccines are in development and urges patients and prescribers "to avoid unnecessary use of antibiotics."
Sources: Hsu HE, Shutt KA, Moore MR, et al. Effect of pneumococcal conjugate vaccine on pneumococcal meningitis. N Engl J Med. 2009;360(3):244-256; Paediatric vaccine effectively prevents pneumococcal meningitis. Doctor's Guide. http://www.docguide.com.
Proton pump inhibitors neutralize clopidogrel
Patients who take clopidogrel (Plavix) after acute myocardial infarction (AMI) are at much greater risk for having another AMI if they also take a proton pump inhibitor such as omeprazole, according to a new study. Because many proton pump inhibitors inhibit the cytochrome P450 2C19 metabolic pathway, they may alter clopidogrel's pharmacodynamics and reduce its antiplatelet activity. Clopidogrel is prescribed after AMI to prevent coronary events by preventing platelet aggregation, which prevents recurrent thrombus formation.
Researchers identified more than 13,000 patients who were prescribed clopidogrel after an AMI. Of these patients, 734 were readmitted with AMI. Among patients prescribed a proton pump inhibitor along with clopidogrel, the risk of reinfarction within 90 days was 27% greater than it was with patients who took only clopidogrel. An exception to this finding was pantoprazole (Protonix), a proton pump inhibitor that follows a different metabolic pathway and appears not to affect clopidogrel metabolism.
Source: Juurlink DN, Gomes T, Ko DT, et al. A population-based study of the drug interaction between proton pump inhibitors and clopidogrel. CMAJ. 2009 Jan 28. http://www.cmaj.ca.