The effect of medroxyprogesterone acetate (MPA) on respiratory drives was measured in a double-blind, cross-over study of six supine normal males. Standard respiratory parameters were compared to mouth occlusion pressure (P0.1). Subjects took MPA (20 mg) or placebo three times a day for two weeks. Then a two-week washout period was followed by two weeks of the alternate drug. Ventilatory and P0.1 responses to eucapnic hypoxia (HVR) and hyperoxic hypercapnia (HCVR) were measured each week. HVR was evaluated by using A and Ap, the shape parameters of the hyperbolic curves derived from plotting V̇E and P0.1 versus PAO 2. HCVR was evaluated by the equation V̇E = S(PACO 2-B), where S is the slope (ΔVE/ΔPACO 2) and B is the extrapolated intercept on the PACO 2 axis. In these normal subjects, ventilation and P0.1 were highly correlated in a linear relationship (0.88 < r < 0.98, p < 0.0001). MPA significantly increased resting ventilation and lowered resting PACO 2. HVR was increased and A[p] was significantly higher in subjects on MPA. The slope of HCVR was increased at 14 days. We conclude that MPA augments resting ventilation, HVR and HCVR.
|Original language||English (US)|
|Number of pages||9|
|Journal||Clinical Respiratory Physiology|
|State||Published - 1980|
All Science Journal Classification (ASJC) codes
- Pulmonary and Respiratory Medicine