Medroxyprogesterone (MPA) is well r...

Medroxyprogesterone (MPA) is well recognized as a respiratory stimulant. In normal man the oral administration of the mix with drugs has been shown to increase the ventilatory rejoinder to both hypercapnia and hypoxia.[1] The exact site of this action is unknown, if it be not that cross-circulation studies in dogs put in mind of that the peripheral chemoreceptor is not essential for the ventilatory response[2] Further, the discovery of MPA-related materials in the cerebral spinal fluid of healthy male offers during drug administration suggests that it could potentially set to work its effect by some central mechanism.[3]

It was a natural extension from previous work to use MPA as a therapeutic agent in the treatment of obstructive be still apnea. Studies by Lyon and Huang[4] and Sutton et al[5] showed that MPA improved oxygenation and corrected hypercapnia in patients with the obesity-hypoventilation syndrome Further, early descriptive work of patterns of apnea, hypopnea, and oxygen desaturation in normal enthralls showed that these nocturnal conclusions were more common in post-menopausal women than menstruating women[6] undivided popular theory to explain this observation was that progesterone was exerting a certain number of protective effect on the latter form into groups of women through its ventilatory stimulating effects[6]

The studies upon the effects of MPA in obstructive be motionless apnea have produced conflicting and oftentimes disappointing results. Strohl et al[7] establish that four of nine patients improved with MPA treatment. They documented a decrease in apneas, a reduction in percentage of apnea time, a decrease in pedal edema and weight los in these patients. There was regression formerly the drug was stopped. It is not clear, however, whether the improvement in weight contributed to the decrease in the severity of the apneas. In contrast to this investigation two other previous investigations showed no improvement in the severity of drowse apnea in a total of 20 men treated with MPA.[8,9] The latter contemplation specifically investigated eucapnic patients, while Orr and his colleagues[8] included three patients who were hypercapnic.

This altercation prompted an extremely well done, randomized double-blind crossover studious mood presented by W.R. Cook and colleagues in this issue of Chest (see page 262) Ten male patients, with obstructive rest apnea were either given placebo or a large 150 mg/day dose of MPA for single in kind week. Plasma levels of MPA and testosterone were monitored to make secure absorption of the drug and hormonal activity. Weight remained constant completely through the study. MPA did not arise in any change in slumber parameters in any of the hypercapnic or normocapnic patients.

From these studies undivided can definitely conclude that MPA has absolutely no part in the treatment of the normocapnic patient with obstructive lie in the grave apnea. The data from hypercapnic patients, however, are still conflicting, especially if united accepts that many of the patients not absented by Lyons and Huang[4] and Sutton et al[5] with the obesity-hypoventilation syndrome also had obstructive lie in the grave apnea. Since sleep monitoring technology was not available at the time of those evaluations, we have absolutely no way of knowing whether any nocturnal nap events would have improved with the resolution of daytime line gas abnormalities seen in these patients.

With the advent of nasal continuous positive airway constraining force MPA should not be considered first-line therapy for obstructive rest apnea in patients with hypercapnia. If united plans to use MPA as a treatment in these hypercapnic patients, common must balance the potential benefits against the not insignificant cost of the drug and potential side general intents These include impotence, breast discomfort, hirsutism, alopecia, and thromboembolic disease.[9] The feminizing forces of the drug are not surprising considering the significant fall in testosterone life-current levels demonstrated by the existing study. Further, patients should not be given the mix with drugs without close follow-up. Since adequate plasma of the same heights and maximal respiratory effects of MPA are reached in the same week,[3] a decision about the efficacy of the put drugs into can be made fairly quickly. the same should repeat not only a daytime vital current gas analysis, but also an all-night polysomnography.

REFERENCES

1 Zwillich CW Natalino MR Sutton FD Weil JV validitys of progesterone on chemosensitivity in normal men J Lab Clin M 1978; 92:262-69

2 Mei s Gort D, Kao F. The investigation of respiratory events of progesterone in cross-circulated dogs. F Proc 1977; 36:489

3 Skatrud JB Dempsey JA, Kaiser DG Ventilatory answer to medroxyprogesterone acetate in normal subjects: time course and mechanism. J Appl Physiol 1978; 44:939-44

4 Lyon HA, Huang CT Therapeutic use of progesterone in alveolar hypoventilation associated with obesity. Am J M 1968; 44:881-88

5 Sutton FD Zwillich CW Creagh CE Pierson DJ Weil JV Progesterone for outpatient treatment of Pickwickian syndrome Ann Intern M 1975; 83:476-79