Proposed Lyme disease guidelines focus on appropriate diagnosis, treatment

Abstract

Earlier this summer, the Infectious Diseases Society of America (IDSA), along with other organizations, released a draft of new guidelines for preventing, diagnosing, and treating Lyme disease. Lyme disease, an infectious disease caused by the Borrelia bacterium spread by ticks, affects more than 300,000 people a year in the United States, according to CDC. Incidences are not slowing down, either. CDC estimated that the number of Lyme disease cases increased 17% from 2016 to 2017, when data were last available. For the first time, the new guidelines separate Lyme disease from other diseases. The previous IDSA guidelines for Lyme disease, published more than a decade ago, were combined with other tick-borne diseases. “Having updated guidelines is important for clinicians to stay up to date in order to provide the best care for their patients,” said Erika Ernst, PharmD, BCPS, BCIDP, FCCP, an associate professor at the University of Iowa College of Pharmacy. “The IDSA plans to review the newer guidelines more frequently and make statements about whether they are still up to date or in need of panel review. This will be helpful for clinicians to know if the guidelines remain current.” The draft guidelines strongly recommend prophylactic antibiotic therapy for adults and children within 72 hours of removal of a high-risk tick bite. A tick bite is considered high risk if it’s from an Ixodes tick, from a highly endemic area, or from a tick engorged and attached for 36 hours or more. The preferred antibiotic regimen for an Ixodes high-risk tick bite is a single dose (200 mg) of oral doxycycline. Drugs and drug classes not indicated for treatment of Lyme disease▪First-generation cephalosporins▪Fluoroquinolones▪Aminoglycosides▪Pyrazinamide▪Vancomycin cephalosporins▪Tigecycline▪Metronidazole▪Tinidazole▪Rifampin▪Hydroxychloroquine▪Fluconazo ▪First-generation cephalosporins▪Fluoroquinolones▪Aminoglycosides▪Pyrazinamide▪Vancomycin cephalosporins▪Tigecycline▪Metronidazole▪Tinidazole▪Rifampin▪Hydroxychloroquine▪Fluconazo To treat early localized Lyme disease, the guidelines strongly recommend either a 10-day course of doxycycline or a 14-day course of amoxicillin, cefuroxime axetil, or phenoxymethylpenicillin, rather than a longer treatment course. Acute treatment should not exceed 21 days. The guidelines provide specific recommendations for treatment duration. This is both important and necessary, Ernst noted, because some patients are treated for long periods without evidence to support any benefit of doing so. The guidelines also cover Lyme disease testing and diagnosis, as well as evaluating patients with “chronic” Lyme disease, which Ernst said is not the preferred terminology. “Patients may experience persistent or recurring symptoms after being diagnosed and treated for Lyme disease, but there is no evidence that this represents ongoing infection, and additional antibiotic therapy is not recommended in this case.” Ernst said a crucial addition to the guidelines is the summary for using doxycycline in young patients. “Specifically, doxycycline for 10 days in children, even those younger than 8 years, carries a low risk for teeth staining,” she said. “This information may be new for some pharmacists. The teeth staining is seen primarily with tetracycline—the parent compound—and not derivatives like doxycycline.” Overall, doxycycline is safe for children for prophylaxis (a single dose) or for short-term therapy of 10 days.However, health care practitioners should be cautious with use of doxycycline in patients who are pregnant or breastfeeding, since adverse effects have not been studied in this population. Oral therapy is preferred in most cases, but indications for I.V. therapy—for example, with a hospitalized patient—are also discussed in the draft guidelines. Taking precautions to prevent a tick bite should be properly communicated to individuals, as well. The guidelines include suggestions for protection against a tick bite, such as wearing long pants and sleeves outdoors, bathing after possible exposure, and using repellents. While most Lyme disease cases in the United States are currently found in three areas—the Northeast, the upper Midwest, and northern California—the geographic risk is expanding. Health professionals and the public should consult CDC and state health departments for the most current information on the areas of existing and emerging Lyme disease risk. The draft guidelines focus a lot of attention on diagnosis, which is often one of the more challenging aspects for health care providers to get right. Ernst said it’s important for pharmacists and other health care practitioners to know that it is ideal to diagnose Lyme disease using an FDA-approved testing method. Currently, the only FDA-approved diagnostic assays for Lyme disease are antibody tests. But as the guidelines state, as an indirect detection method, antibody testing for Lyme disease has some limitations. “To address these limitations, numerous direct and nonantibody indirect methods have been proposed or developed. At present, only a few such assays are useful for clinical diagnosis, and these are only useful as adjunctive tests in select clinical scenarios when two-tiered serologic testing is positive,” the guidelines note. IDSA collaborated with the American Academy of Neurology and the American College of Rheumatology on the guidelines. The organization opened the draft for public comment this summer through early August.