CARDIAC CARE
Amiodarone vs. digoxin for A-fib
When your patient has atrial fibrillation (A-fib) and a rapid ventricular rate, the best bet for controlling his heart rate may be amiodarone instead of digoxin, according to a study published in the International Journal of Cardiology.
The study compared treatment with a single 0.6-mg bolus of digoxin with an initial 450-mg bolus of amiodarone followed immediately by a 10-mL flush of saline to 100 patients with A-fib and a ventricular rate above 135 beats/min. In both groups, patients whose heart rates continued to exceed 100 beats/min after 30 minutes received a second bolus of the treatment drug (300 mg of amiodarone or 0.4 mg of digoxin).
At 60 minutes, ventricular heart rates averaged 94.2 beats/min in patients receiving amiodarone and 105.3 beats/min in those receiving digoxin. Normal sinus rhythm was achieved within 30 minutes in 28% of amiodarone-treated patients and 6% of digoxin-treated patients.
Patients who received amiodarone treatment were more likely to develop hypotension, but investigators pointed out that fluid administration was usually enough to maintain blood pressure.
SOURCE:
Hofmann R, et al. Effects of a high dose intravenous bolus amiodarone in patients with atrial fibrillation and a rapid ventricular rate. International Journal of Cardiology. 110(1):27-32, June 7, 2006.
SMOKING CESSATION
A new way to kick the habit
If your patient wants to stop smoking, he may do better with varenicline (Champix), a new prescription drug for smoking cessation, than with bupropion (Zyban). According to three studies published in the JAMA, varenicline may be more effective and promote lengthier smoking abstinence.
Unlike bupropion, which is believed to inhibit the reuptake of dopamine and norepinephrine, varenicline targets nicotinic receptors to stimulate dopamine release. The "flood" of dopamine curbs nicotine cravings in smokers; at the same time, the drug blocksthe reinforcing effects of smoked nicotine.
Two of the studies were sponsored by Pfizer, the drug's maker. One tested the effectiveness of varenicline against bupropion and placebo administered for 12 weeks to individuals who smoked at least 10 cigarettes per day. Varenicline's immediate abstinence rate was 44%, compared with 29.5% in bupropion users and 17.7% in placebo subjects. At 1 year, varenicline's abstinence rate dropped but remained higher than that of bupropion. The other Pfizer study was similar, but produced slightly better 1-year abstinence rates for the new drug: 23%, compared with 14.6% for bupropion users and 10.3% for placebo subjects.
The third study measured length of abstinence in smokers who abstained for at least 7 days after a 12-week course of varenicline and another 12-week course of either varenicline or placebo (randomized). The 1-year abstinence rate in the continuous varenicline group was 43.6%, compared with 36.9% in those who'd been switched to placebo.
Despite the drug's success in these studies, an accompanying JAMA editorial cautions that varenicline isn't a "cure" for smoking. "Patients currently cannot and probably never will simply be able to "take a pill' that will make them stop smoking," warn the editors.
SOURCE:
Journal of the American Medical Association. 296(1):47-55, 56-63, 64-71, 94-95, July 5, 2006.
HPV INFECTION
HPV vaccine recommended for all girls
Girls age 11 and older and women up to age 26 should be immunized against human papilloma virus (HPV) infection, says the Advisory Committee on Immunization Practices (ACIP), which advises the U.S. Centers for Disease Control and Prevention. ACIP recommends that Gardasil (Merck & Co.) be used to vaccinate all girls ages 11 and 12, girls and women ages 13 to 26 who haven't yet been vaccinated, and women who've had genital warts or other similar conditions or who've had abnormal Pap smears.
The goal of ACIP's recommendation is to reduce the occurrence of cervical cancer caused by HPV. In clinical trials, Gardasil was shown to prevent almost all lesions that cause genital warts and cervical cancer. LPN
DID YOU KNOW
Statin use may reduce your risk of nuclear cataract, the most common type of age-related cataract. In a study based on results of the landmark Beaver Dam Eye Study on the aging eye, 12.2% of statin users developed nuclear cataract compared with 17.2% of nonusers. What's the connection? It's believed that statins show antioxidant activity-and oxidative stress has long been thought to be a risk factor for age-related cataract.
SOURCE:
Klein BEK, et al. Statin use and incident nuclear cataract. Journal of the American Medical Association. 295(23):2752-2758, June 21, 2006.