What is the drug of choice for non-typhoidal Salmonella bacteremia?

Treatment of Non-Typhoidal Salmonella Bacteremia

For non-typhoidal Salmonella bacteremia, the drug of choice is a fluoroquinolone, specifically ciprofloxacin, which should be administered at 500 mg twice daily for at least 14 days. 1

First-line Treatment Options

• Ciprofloxacin is the primary drug of choice for non-typhoidal Salmonella bacteremia in immunocompetent adults, typically administered at 500 mg twice daily for 14 days 1
• For severe infections or in immunocompromised patients, initial combination therapy with ceftriaxone (2 g once daily IV) plus ciprofloxacin is recommended until susceptibility results are available 1
• After susceptibility testing, therapy can be de-escalated to a single appropriate agent based on results 1

Alternative Treatment Options (Based on Susceptibility)

• Trimethoprim-sulfamethoxazole (TMP-SMZ) if the organism is susceptible 1
• Amoxicillin (500 mg three times daily) if susceptibility is confirmed 1
• Ceftriaxone (2 g daily IV) is effective against Salmonella species, including non-typhoidal strains 2
• Azithromycin may be considered as an alternative, particularly in areas with high fluoroquinolone resistance 3

Special Populations

Immunocompromised Patients

• Require longer treatment courses (14 days or longer if relapsing) 1
• May benefit from combination therapy initially (ceftriaxone plus ciprofloxacin) 1
• Long-term suppressive therapy may be needed to prevent recurrence in HIV-infected patients 1

Children

• Fluoroquinolones should be used with caution and only if no alternatives exist 1, 4
• Preferred options include TMP-SMZ, ampicillin, cefotaxime, or ceftriaxone 1
• Treatment is particularly important for infants less than 3 months of age due to higher risk of bacteremia 4

Pregnant Women

• Fluoroquinolones should be avoided 1
• Recommended alternatives include ampicillin, cefotaxime, ceftriaxone, or TMP-SMZ 1

Prevention of Recurrence

• For patients who have experienced Salmonella bacteremia, especially those who are immunocompromised, long-term suppressive therapy with ciprofloxacin is recommended to prevent recurrence 1
• The typical regimen for suppressive therapy is ciprofloxacin 500 mg twice daily for at least 2 months 1

Clinical Considerations and Pitfalls

• Increasing fluoroquinolone resistance has been reported in Salmonella isolates, with rates varying by region and serotype 5, 6
• Testing for nalidixic acid resistance is recommended, as this can indicate decreased fluoroquinolone susceptibility even when MICs appear within the susceptible range 6
• Short-course fluoroquinolone therapy should be avoided for nalidixic acid-resistant isolates 6
• Multidrug-resistant Salmonella strains are increasingly common, necessitating susceptibility testing to guide therapy 7
• Azithromycin may be preferred in some settings due to lower resistance development compared to fluoroquinolones 3

Treatment Duration

• Minimum 14 days for bacteremia in immunocompetent patients 1
• Extended treatment (>14 days) for immunocompromised patients or those with persistent or recurrent infection 1
• Secondary prophylaxis may be required for immunocompromised patients, particularly those with HIV infection 1