['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.', 'To evaluate the efficacy of intravenous doxycycline as empirical treatment in hospitalized patients with mild to moderately severe community-acquired pneumonia.', '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.', '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.'] Is doxycycline a cost-effective therapy for hospitalized patients with community-acquired pneumonia?