This article involved a double-blind randomized controlled trial conducted from November 2014 to February 2017. The study enrolled 315 patients aged 18 years and older who were diagnosed with acute bacterial sinusitis in the Internal Medicine/Pediatrics department at Albany Medical College. Participants were randomized in a 1-to-1 ratio and given either a standard dose of Amoxicillin/Clavulanate 875 mg / 125 mg twice daily for 7 days or high dose Amoxicillin/Clavulanate 1000 mg / 62.5 mg Extended Release twice daily for 7 days or high dose Amoxicillin/Clavulanate 875 mg / 125 mg Immediate Release plus Amoxicillin 875 mg Immediate Release [with the latter formulation initiated after patient #180 due to lack of the previous high dose formulation]. The primary outcome was the percentage of patients in each group who reported feeling “a lot better” or “no symptoms” after 3 days of treatment. The secondary outcomes included the percentage of patients in each group who reported feeling “a lot better” or “no symptoms” at Day 10 and the average changes in the rating of the Sinonasal Outcome Test [SNOT-16] questionnaire at Day 3 and Day 10 compared to baseline ratings.
Overall, higher efficacy was seen in the high dose group treated with the Immediate Release formulation compared to the standard dose with major improvement in symptoms being 52.4% versus 34.4% after 3 days of treatment. The Immediate Release high dose group, however, also had a 15.8% versus 4.8% increase in severe diarrhea by Day 3. Vaginal discharge and itching were also more common in the high dose group than the standard dose group at Day 3. Though, such adverse effects mostly resolved by Day 10. There was also no significant difference found between the two groups in secondary outcomes, showing that despite more rapid improvement with the high dose treatment, most patients in both groups reported major improvement at Day 10. The study also found that a higher percentage of patients who experienced adverse effects reported that they would not take the high dose formulations again despite major improvement at Day 3.
Ultimately, patients should be presented with all available options in the treatment of acute bacterial sinusitis so that they can make an informed decision, weighing the risks, such as severe diarrhea, versus the benefits, such as more rapid improvement in the short term, but also be informed that most patients get better by Day 10 regardless of treatment. It is also important to consider antimicrobial resistance rates as findings may not be applicable to areas where there is a high prevalence of resistant bacteria.
