Combined treatment with acetazolamide and medroxyprogesterone in chronic obstructive pulmonary disease patients.

Medroxyprogesterone acetate (MPA) and acetazolamide (ACET) are two ventilatory stimulants which are used in hypoxic and hypercapnic patients with chronic obstructive pulmonary disease (COPD). In a double-blind randomised study, the effects of a 2-week treatment with MPA (30 mg b.i.d.) or ACET (250 mg b.i.d.), followed by a 2-week treatment with a combination of both drugs (MPA/ACET), on daytime and nocturnal ventilatory and blood gas parameters in 17 stable hypercapnic COPD patients were investigated. ACET, MPA and MPA/ACET treatment decreased mean daytime carbon dioxide tension in arterial blood by 0.4, 0.7 and 1.2 kPa, respectively. Minute ventilation was improved only with combined therapy, from 9.3 to 11.2 L x min(-1). With MPA/ACET therapy, the hypercapnic and hypoxic ventilatory responses significantly increased, from 3.7 to 5.8 L x min(-1) x kPa(-1) and from -0.13 to -0.40 L x min(-1) x %(-1), respectively. The mouth exclusion pressure response to hypoxia increased during combination therapy, from -0.01 to -0.03 kPa %(-1). Nocturnal end-tidal carbon dioxide tension decreased with MPA and MPA/ACET treatment, by 0.9 and 1.4 kPa, respectively. MPA/ACET significantly increased mean nocturnal arterial oxygen saturation values, from 85.5 to 90.2%. The authors conclude that short-term combined treatment with medroxyprogesterone acetate and acetazolamide has a more favourable effect on day and night-time blood gas values and chemical drive than single drug treatment.