The purpose of the study reported here was to investigate the impact of prophylaxis against gram-positive
infections in patients undergoing high-dose
chemotherapy and autologous
bone marrow transplantation in a randomized trial. Forty-three patients undergoing high-dose
chemotherapy with autologous bone marrow transplant were enrolled in a nonblinded randomized trial to receive or not to receive prophylaxis for gram-positive
infections with 10(6) U of
penicillin intravenously (i.v.) every 6 h (q6h) (if
penicillin allergic, 750 mg of
vancomycin i.v. q12h) in addition to standard antimicrobial prophylaxis with 400 mg of
norfloxacin orally three times a day, 200 mg of
fluconazole orally once a day, and 5 mg of
acyclovir per kg of
body weight i.v. q12h. The patients were being treated for
germ cell cancer (n = 15),
breast cancer (n = 16),
Hodgkin's disease (n = 3),
non-Hodgkin's lymphoma (n = 4),
acute myeloid leukemia (n = 1),
acute lymphoblastic leukemia (n = 1), and
ovarian cancer (n = 3). The trial was stopped because of excess morbidity in the form of streptococcal
septic shock in the group not receiving gram-positive prophylaxis. There were significantly fewer overall
infections (10 versus 3; P = 0.016) and
streptococcal infections (9 versus 1; P = 0.0078) in the group receiving gram-positive prophylaxis. There were no significant differences in the numbers of deaths, duration of broad-spectrum
antibiotics, or incidence of neutropenic
fever between the two groups. Prophylaxis for gram-positive
infections with
penicillin or
vancomycin is effective in reducing the incidence of
streptococcal infections in patients undergoing high-dose
chemotherapy and autologous bone marrow transplant. However, this approach may carry a risk of fostering resistance among streptococci to
penicillin or
vancomycin.