Cyclooxygenase inhibition and improved oxygenation in patients with pulmonary complications of AIDS

Abstract

Pulmonary involvement related to acquired immunodeficiency syndrome (AIDS) compromises oxygenation, by both ventilation-perfusion mismatch and increased shunt. In animal studies, meclofenamate, a cyclooxygenase inhibitor, decreases shunt and improves oxygenation. Oral meclofenamate (200 mg) was given to seven patients who had AIDS with pulmonary involvement (Pneumocystis carinii pneumonia or Kaposi's sarcoma) and abnormal gas exchange. Arterial PO2 was measured 30 and 0 minutes before and 45 and 60 minutes after administering meclofenamate, and the shunt fraction (venous admixture) was estimated. In all patients, arterial PO2 increased, shunt decreased, and PCO2 and pH did not change after meclofenamate therapy. Cyclooxygenase inhibition appears to have strengthened hypoxic vasoconstriction and decreased the shunt fraction, possibly by eliminating prostacyclin-induced vasodilation in diseased lung regions. Cyclooxygenase inhibition may be of benefit in the management of hypoxemia asociated with AIDS and warrants further investigation.