In a double-blind, controlled trial (Study 1) conducted in Peru and Egypt in adults and adolescents with diarrhea with one or more enteric symptoms (e.g., abdominal pain, nausea, vomiting, fever, abdominal distention, loss of appetite, flatulence) caused by Giardia lamblia, a three-day course of treatment with Alinia Tablets administered 500 mg BID was compared with a placebo tablet for 3 days. A third group of patients received open-label Alinia for Oral Suspension administered 500 mg/25 mL of suspension BID for 3 days. A second double-blind, controlled trial (Study 2) conducted in Egypt in adults and adolescents with diarrhea and with or without enteric symptoms (e.g., abdominal colic, abdominal tenderness, abdominal cramps, abdominal distention, fever, bloody stool) caused by Giardia lamblia compared Alinia Tablets administered 500 mg BID for 3 days to a placebo tablet. For both of these studies, clinical response was evaluated 4 to 7 days following the end of treatment. A clinical response of ‘well’ was defined as ‘no symptoms, no watery stools and no more than 2 soft stools with no hematochezia within the past 24 hours’ or ‘no symptoms and no unformed stools within the past 48 hours.’ The following clinical response rates were obtained:
Adult and Adolescent Patients with Diarrhea Caused by Giardia lamblia
Clinical Response Rates* 4 to 7 Days Post-therapy
% (Number of Successes/Total)
* Includes all patients randomized with Giardia lamblia as the sole pathogen. Patients failing to complete the studies were treated as failures.
¶ Clinical response rates statistically significantly higher when compared to placebo.
§ The 95% confidence interval of the difference in response rates for the tablet and suspension is (-14%, 17%).
Some patients with ‘well’ clinical responses had Giardia lamblia cysts in their stool samples 4 to 7 days following the end of treatment. The relevance of stool examination results in these patients is unknown. Patients should be managed based upon clinical response to treatment.