Am. J. Respir. Crit. Care Med., Vol 151, No. 4, 04 1995, 1228-1232.
Effects of erythromycin on the rabbit pleura: its potential role as a pleural sclerosant
P Carvalho, LL Knight, RD Olson, JJ Crowley, PA Hawk and NB Charan
Pulmonary Research Laboratory, VA Medical Center, Boise, Idaho 83702- 4598.
Tetracycline (TCN) has been considered the agent of choice for pleurodesis
in patients with symptomatic malignant pleural effusions and recurrent
pneumothoraces. However, the intravenous form of TCN used for pleurodesis
is no longer available. Erythromycin, like TCN, often produces irritation
when administered intravenously. In view of these irritant properties, we
tested the effect of erythromycin as a pleural sclerosant in rabbits as
compared with TCN. Normal saline was used as a control. Adult rabbits
weighing 2.5 to 3.0 kg underwent sterile placement of a silastic pleural
tube in the right pleural space. Erythromycin (n = 17) or TCN (n = 6), each
in doses of 35 mg/kg in 2 ml saline, was administered via the tube. Control
animals (n = 6) received 2 ml saline. The chest tubes were left in place
for removal of pleural fluid and to maintain lung expansion. Animals were
killed 8 d after receiving the various treatments, and their pleural
surfaces were examined grossly and histologically. Numerous adhesions were
present between the visceral and parietal pleurae in all animals receiving
erythromycin and TCN, but not in those receiving saline. On light
microscopy, pleurae treated with erythromycin or TCN were histologically
identical, showing inflammation, edema, and fibroblast proliferation in the
submesothelial tissues. The saline-treated animals had a normal pleura.
Because erythromycin produced pleural inflammation and adhesions within 8 d
of treatment, we propose that it may have a potential role as a pleural
sclerosant.
