Omeprazole inhibits phagocytosis and acidification of phagolysosomes of normal human neutrophils in vitro.

We postulated omeprazole inhibition of the neutrophil proton pump, impairing phagocytosis and phagolysosomal acidification. Neutrophils from healthy human beings were treated with omeprazole prodrug 0.5 mM/l or acid activated omeprazole 0.5 mM/l, then incubated with killed Saccharomyces cerevisiae stained with bromcresol purple. Wet mounts were done at 10, 30 and 60 minutes. Percent neutrophils phagocytosing, percent yeast phagocytosed, and yeast per phagocytosing neutrophil were significantly decreased in acid activated omeprazole compared to controls and omeprazole prodrug. In contrast, percent acidification of intracellular yeast was significantly lower in both omeprazole prodrug and acid activated omeprazole compared to controls. Over time, control neutrophils showed an increase in percent yeast phagocytosed and yeast per phagocytosing neutrophil. When treated with acid activated omeprazole, the percent of neutrophils phagocytosing progressively decreased over time. We observed 1) omeprazole prodrug does not inhibit neutrophil phagocytosis but does inhibit phagolysosomal acidification, whereas 2) acid activated omeprazole inhibits both neutrophil phagocytosis and phagolysosome acidification. We conclude that omeprazole impairs these neutrophil functions in vitro.

Doxycycline is a cost-effective therapy for hospitalized patients with community-acquired pneumonia.

BACKGROUND: Doxycycline has a high degree of activity against many common respiratory pathogens and has been used in the outpatient management of lower respiratory tract infections, including pneumonia. OBJECTIVE: To evaluate the efficacy of intravenous doxycycline as empirical treatment in hospitalized patients with mild to moderately severe community-acquired pneumonia. PATIENTS AND METHODS: We conducted a randomized prospective trial to compare the efficacy of intravenous doxycycline with other routinely used antibiotic regimens in 87 patients admitted with the diagnosis of community-acquired pneumonia. Forty-three patients were randomized to receive 100 mg of doxycycline intravenously every 12 hours while 44 patients received other antibiotic(s) (control group). The 2 patient groups were comparable in their clinical and laboratory profiles. RESULTS: The mean+/-SD interval between starting an antibiotic and the clinical response was 2.21+/-2.61 days in the doxycycline group compared with 3.84+/-6.39 days in the control group (P = .001). The mean+/-SD length of hospitalization was 4.14+/-3.08 days in the doxycycline group compared with 6.14+/-6.65 days in the control group (P = .04). The median cost of hospitalization was $5126 in the doxycycline group compared with $6528 in the control group (P = .04). The median cost of antibiotic therapy in the doxycycline-treated patients ($33) was significantly lower than in the control group ($170.90) (P<.001). Doxycycline was as efficacious as the other regimens chosen for the treatment of community-acquired pneumonia. CONCLUSION: Doxycycline is an effective and inexpensive therapy for the empirical treatment of hospitalized patients with mild to moderately severe community-acquired pneumonia.