FDA approves Anthrasil to treat inhalational anthrax
BY DEEPAK CHITNIS
FRONTLINE MEDICAL NEWS
The Food and Drug Administration has approved Anthrasil, Anthrax Immune Globulin Intravenous (Human), for treatment of inhalational anthrax when used with appropriate antibacterial drugs.
Inhalational anthrax is caused by breathing in Bacillus anthracis spores, which can occur after exposure to infected animals or contaminated animal products, or as a result of an intentional release of spores. In a statement, Dr. Karen Midthun – director of the FDA’s Center for Biologics Evaluation and Research – explained that Anthrasil “will be stored in U.S. Strategic National Stockpile to facilitate its availability in response to an anthrax emergency.”
Anthrasil was purchased by the U.S. Department of Health & Human Services’ Biomedical Advanced Research and Development Authority (BARDA) in 2011, but because it was not approved, its use prior to FDA approval would have required an emergency use authorization from the FDA.
The efficacy of Anthrasil was studied in animals because it was not feasible or ethical to conduct adequately controlled efficacy studies in humans, the FDA said. Monkeys and rabbits were exposed to Bacillus anthracis spores, and subsequently given either Anthrasil or a placebo. The survival rate for monkeys given Anthrasil was between 36% and 70%, with a trend toward increased survival at higher doses of Anthrasil. None of the monkeys given placebo survived. Rabbits had a 26% survival rate when given the drug, compared to 2% of those given placebo. A separate study exposed rabbits to Bacillus anthracis and treated them with either antibiotics or a combination of antibiotics and Anthrasil; survival rates were 71% for those treated with the combination and 25% for those treated with antibiotics only.
Safety was tested in 74 healthy human volunteers and the most commonly reported side effects were headache, back pain, nausea, and pain and swelling at the infusion site.
Anthrasil is manufactured by Cangene Corporation, based in Winnipeg, Canada, which developed the drug in collaboration with BARDA.
FDA: Amiodarone plus some hepatitis C antivirals may result in bradycardia
BY ELIZABETH MECHCATIE
Frontline Medical News
Taking the antiarrythmic drug amiodarone with the hepatitis C antiviral drugs ledipasvir and sofosbuvir, or with sofosbuvir plus another direct-acting antiviral drug, has been associated with cases of symptomatic bradycardia – including a fatal cardiac arrest – according to the Food and Drug Administration.
Because of the reports, the antiviral drugs’ labels now recommend against using amiodarone with those hepatitis C drugs.
An FDA statement described the bradycardia cases as “serious and life-threatening.” Gilead Sciences markets the ledipasvir and sofosbuvir combination as Harvoni and markets sofosbuvir as Sovaldi to treat chronic hepatitis C virus (HCV) infection.
Gilead issued a “Dear Health Care Provider” letter that provides further details of the cases. There have been nine postmarketing reports of symptomatic bradycardia in patients who were taking amiodarone with Harvoni; amiodarone with Sovaldi plus another hepatitis C antiviral drug, simeprevir (Olysio); or amiodarone with an investigational hepatitis C antiviral drug, daclatasvir.
Of those cases, six occurred with in the first 24 hours of starting treatment with the antivirals, and three cases occurred within the first 2-12 days after antiviral therapy was started. A pacemaker was needed in three cases, and one case was a fatal cardiac arrest.
In three cases, a “rechallenge with HCV treatment in the setting of continued amiodarone therapy resulted in recurrence of symptomatic bradycardia,” according to the Gilead letter.
The effect of coadministration on the blood levels of the antiviral drugs is not known, nor is the mechanism behind the cardiac effect.
emechcatie@frontlinemedcom.com
Clindamycin, TMP-SMX are equally effective for skin infections
BY MARY ANN MOON
FROM THE NEW ENGLAND JOURNAL OF MEDICINE
Vitals Key clinical point: Clindamycin and TMP-SMX had similar efficacy and side-effect profiles for treating uncomplicated skin infections, including both abscesses and cellulitis. Major finding: At 7-10 days after completing therapy, the rates of cure in the evaluable population were 90% with clindamycin and 88% with TMP-SMX. Data source: A prospective, multicenter, randomized, double-blind clinical trial involving 524 adults and children followed for 1 month after treatment. Disclosures: This trial was supported by the National Institutes of Allergy and Infectious Diseases and the National Center for Advancing Translational Sciences (NCT00730028). Dr. Miller reported receiving consulting fees from Cubist, Durata, and Pfizer; his associates reported ties to Cubist, Pfizer, EMMES, Theravance, AstraZeneca, Trius, Merck, and Cerexa. |
Clindamycin and trimethoprim-sulfamethoxazole are similarly safe and effective for treating uncomplicated skin infections, including both cellulitis and abscesses, in ambulatory settings in regions where MRSA is endemic.
The data comparing these two agents in an ambulatory setting are limited, though both are commonly recommended as empirical therapy for skin infections in patients who present to clinics and emergency departments and have only minor or no coexisting conditions, said Dr. Loren G. Miller of the Los Angeles Biomedical Research Institute and the division of infectious diseases at Harbor-UCLA Medical Center, and his associates.