Early lyme disease.(Drug Update)

Management of Lyme disease focuses on treatment rather than prevention. A vaccine for Lyme disease, which was seemingly safe and effective but also carried a high price tag, was pulled from the market in February 2002 because of low sales and concerns about possible complications.

Infection with Lyme disease is characterized as early or late. Early infection refers to symptoms within 6 months of a bite from an infected tick; late-stage Lyme disease refers to symptoms that have persisted for 6 months or longer. Erythema migrans, the characteristic bull's-eye rash, appears only in the early stage; neurologic involvement may develop at any time. Lyme disease is not contagious and is rarely, if ever, fatal.

The ideal time to treat Lyme disease is in the early phase. Oral dosing with doxycycline or amoxicillin is the treatment of choice for most patients. The optimal duration of treatment for early disease remains controversial. The Infectious Diseases Society of America (IDSA) in 2000 recommended initial treatment with oral antibiotics for 14-21 days, but some experts now suggest treatment for 10-14 days is adequate. They cite study results showing that a 10-day course of doxycycline was as effective as treatment for 20 days.

For patients who realize they've been bitten by a tick that has been attached and feeding for some time (more than 48 hours), a single 200-mg dose of doxycycline taken with food has been shown to be 87% effective in preventing Lyme disease. However, since only one-third of Lyme disease patients recall a tick bite, the absence of a bite in a patient's history does not rule out Lyme disease. Guidelines on treating Lyme disease from the IDSA were published in 2000 (Clin. Infect. Dis. 31[suppl. 1]:S1-14, 2000).

 
Drug           Cost/Day*  Dosage  What the Experts Say** 
 
doxycycline      $0.22    100 mg  A top choice for early-stage infection 
hyclate                   b.i.d.  because it is also effective against 
 [Doryx]        [$6.12]           other tick-borne pathogens. May cause 
 [Vibramycin]   [$9.02]           photosensitivity, so patients should 
                                  be cautioned about using a good 
                                  sunblock or avoiding sun exposure. 
                                  Take with food for best results; space 
                                  doses 12 hours apart if possible. 
                                  Duration of treatment is 
                                  controversial; recommendations range 
                                  from 10 to 21 days. May be used by 
                                  pregnant women in their first 
                                  trimester but not in second or third 
                                  trimester; compatible with breast- 
                                  feeding. No dosage adjustment needed 
                                  for patients aged 70 years and older 
                                  or for patients with renal failure. 
amoxicillin      $0.39    500 mg  Best alternative for early-stage 
 [Amoxicot]     [$0.90]   t.i.d.  infections in people who can't limit 
 [Moxilin]      [$0.51]           their sun exposure or can't take 
 [Trimox]       [$1.29]           tetracyclines but can take 
                                  penicillins. Ideally, ...