Which antibiotic regimen is appropriate as initial therapy for Whipple disease?

• A. TMP-SMX
• B. Ceftriaxone for 2 weeks IV
• C. Doxycycline
• D. Azithromycin

Answer: (B)

Whipple disease is caused by an intracellular organism that lives inside macrophages and can involve the central nervous system. Treating it effectively requires an antibiotic that is both bactericidal and able to penetrate intracellularly (and, if needed, the CNS). Because of that, the initial phase of therapy uses an IV agent that acts quickly to lower bacterial load and reaches tissues well. Ceftriaxone given IV for about two weeks fits this role well, providing rapid, intracellularly active bactericidal coverage and CNS penetration if needed. After this induction phase, therapy continues with a long course of an oral agent such as trimethoprim-sulfamethoxazole to eradicate residual organisms and reduce relapse risk over the ensuing year.

Why the other options aren’t used as the initial regimen: these agents can be effective later in the overall plan, but they’re not ideal for induction because they’re either not as rapidly bactericidal, have less reliable intracellular penetration, or are more suited to maintenance rather than initial eradication.