From the Research
Blastocystis hominis infections often don't require treatment as many people carry this parasite without symptoms, but for symptomatic patients, metronidazole is the first-line treatment, typically prescribed at 500-750 mg three times daily for 5-10 days, although its efficacy has been questioned in recent studies 1.
Treatment Options
- Metronidazole: 500-750 mg three times daily for 5-10 days, with a clinical response rate of 79.5% but a microbiological response rate of only 48.4% 1
- Alternative medications:
- Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 7 days)
- Nitazoxanide (500 mg twice daily for 3 days)
- Paromomycin (25-35 mg/kg/day in three divided doses for 7 days)
Considerations
- Treatment success varies, and some infections may be resistant to therapy 2
- The decision to treat should be based on symptom severity and the exclusion of other causes of gastrointestinal symptoms, as Blastocystis may be an incidental finding rather than the cause of symptoms
- If symptoms persist after treatment, follow-up with a healthcare provider is recommended to consider alternative diagnoses or treatment approaches
Recent Findings
- A study published in 2017 found that metronidazole had a low efficacy in eradicating Blastocystis hominis in symptomatic patients, with a microbiological response rate of only 48.4% 1
- Another study published in 2015 found that Blastocystis isolates showed little sensitivity to metronidazole and other commonly used antimicrobials, highlighting the need for revised treatment regimens 2