Monitor patients for Fournier gangrene
Sodium–glucose cotransporter-2 (SGLT2) inhibitors such as canagliflozin and dapagliflozin have been associated with necrotizing fasciitis of the perineum, also called Fournier gangrene (FG). This rare urologic emergency is characterized by necrotizing infection of the external genitalia, perineum, and perianal region. In 2018, the FDA required manufacturers of all SGLT2 inhibitors to add new warnings about this risk to the prescribing information and patient Medication Guide.
A recent analysis based on data from the FDA Adverse Event Reporting System and published case reports identified 55 unique cases of FG in patients receiving SGLT2 inhibitors between March 2013 and January 2019. Time to onset of FG after initiation of SGLT2-inhibitor therapy ranged from 5 days to 49 months. All patients were severely ill and required surgical debridement. Complications included diabetic ketoacidosis, sepsis or septic shock, and acute kidney injury. Two patients required lower-extremity amputation and three patients died. In addition, between 1984 and January 2019, the FDA identified 19 FG cases associated with other hypoglycemic agents, including metformin, insulin glargine, short-acting insulin, sitagliptin plus metformin, and dulaglutide.
The investigators say FG is “a newly identified safety concern in patients receiving SGLT2 inhibitors.” They advise healthcare professionals to closely monitor patients using SGLT2 inhibitors for FG and to have a “high index of suspicion” in order to recognize early signs and symptoms, such as tenderness, erythema, or edema of the external genitalia or perineum and a fever above 100.4° F (38° C). Warn patients who develop symptoms to seek immediate medical attention because FG progresses rapidly.
Sources: Bersoff-Matcha SJ, Chamberlain C, Cao C, Kortepeter C, Chong WH. Fournier gangrene associated with sodium-glucose cotransporter-2 inhibitors: a review of spontaneous postmarketing cases. Ann Intern Med. [e-pub May 7, 2019]. US Food & Drug Administration. FDA warns about rare occurrences of a serious infection of the genital area with SGLT2 inhibitors for diabetes. Safety announcement. August 29, 2018.
Folic acid intake lowers maternal risk
The US Preventive Services Task Force recommends that all women of reproductive age take a daily supplement containing 400 to 800 mg of folic acid to reduce the risk of conceiving a child with a neural tube defect. A new study indicates that this intervention also reduces the risk of gestational diabetes mellitus (GDM) in pregnant women.
The study included 14,553 women in the Nurses' Health Study II who reported at least one singleton pregnancy between the 1991 and 2001 questionnaires. Investigators assessed prepregnancy intakes of total folate, supplemental folate, and food folate using a food frequency questionnaire administered every 4 years. Among more than 20,000 pregnancies, they found 824 cases of GDM. Women with adequate total folate intake (≥400 mcg/day) were 22% less likely to develop GDM compared with women who did not take a folic acid supplement. “This association was entirely driven by supplemental folate intake,” the investigators write. They also found that women who consumed at least 600 mcg/day of folic acid were 30% less likely to develop GDM.
If these findings are confirmed by ongoing research, the investigators conclude that “prepregnancy folic acid supplementation could offer a novel and low-cost avenue to reduce GDM risk.”
Sources: Li M, Li S, Chavarro JE, et al. Prepregnancy habitual intakes of total, supplemental, and food folate and risk of gestational diabetes mellitus: a prospective cohort study. Diabetes Care. [e-pub April 22, 2019]. National Institutes of Health. Release: daily folic acid supplement may reduce risk of gestational diabetes. News release. April 29, 2019.
Vaccine approved for certain pediatric patients
Dengvaxia is the first vaccine approved by the FDA to prevent dengue disease caused by all four dengue virus serotypes. It is indicated for children and adolescents age 9 through 16 who have lab-confirmed previous dengue infection and who live in endemic areas, such as the US territories of American Samoa, Guam, Puerto Rico, and the US Virgin Islands.
According to the FDA, dengue is the most common mosquito-borne disease in the world. After a first infection with dengue virus, a person becomes immune to that serotype. However, a second infection with a different serotype can lead to severe disease. The new vaccine was developed to prevent severe disease from a second infection. It has been previously approved in 19 countries and the European Union.
Dengvaxia is not approved for use in anyone who was not previously infected by any dengue virus serotype or for whom this information is unknown. In someone not previously infected, the vaccine may act as a first infection and increase the risk of severe disease if the person is subsequently infected with any dengue virus serotype.
Dengvaxia is a live, attenuated vaccine administered as three separate injections. The initial dose is followed by two additional injections given 6 and 12 months later. The most common adverse reactions—headache, myalgia, arthralgia, fatigue, injection-site pain and low-grade fever—tend to decrease with each subsequent dose.
Source: US Food & Drug Administration. First FDA-approved vaccine for the prevention of dengue disease in endemic regions. News release. May 1, 2019.
Two new drugs treat rare type of amyloidosis
Tafamidis meglumine (Vyndaqel) and tafamidis (Vyndamax) capsules have been approved by the FDA to treat cardiomyopathy caused by transthyretin-mediated amyloidosis (ATTR-CM) in adults. These are the first FDA-approved treatments for ATTR-CM, a rare, debilitating, and often fatal disorder caused by a buildup of amyloid proteins in organs and tissues. Cardiac involvement can lead to shortness of breath, fatigue, heart failure, dysrhythmias, loss of consciousness, and death.
Vyndaqel and Vyndamax have the same active moiety, tafamidis, but they are not substitutable on a milligram-to-milligram basis and their recommended doses differ. The efficacy of tafamidis in treating ATTR-CM was shown in a clinical trial of 441 patients randomized to receive Vyndaqel or a placebo. After an average of 30 months, the survival rate was higher in the Vyndaqel group than in the placebo group. Patients in the Vyndaqel group also had fewer hospitalizations for cardiovascular problems.
Patients in the clinical trial experienced no drug-related adverse reactions, but tafamidis may cause fetal harm when taken during pregnancy. Advise women taking Vyndaqel or Vyndamax to discuss pregnancy planning and prevention with their healthcare provider.
Source: US Food & Drug Administration. FDA approves new treatments for heart disease caused by a serious rare disease, transthyretin mediated amyloidosis. News release. May 6, 2019.