In patients with healthy native kidneys, long-term cyclosporine therapy, even at a low dose (5 mg/kg per day), is nephrotoxic and is associated with a high incidence of hypertension.

The aim of this double blind placebo-controlled cross-over study was to evaluate the effects of fadrozole, a new oral nonsteroidal aromatase inhibitor, on basal and stimulated cortisol and aldosterone secretion at a daily dosage of 4 mg given for 14 days to eight healthy men. After 2 weeks of treatment, fadrozole, compared with placebo, effectively suppressed plasma estrogen levels (P less than 0.05 at 0800 h), but did not affect glucocorticoid secretion either under basal conditions or after stimulation with ACTH. Basal plasma aldosterone levels were not significantly different with fadrozole treatment compared to those after placebo treatment. However, compared with pretreatment values, basal aldosterone secretion appeared impaired (P less than 0.05). A statistically significant blunting of the responses of plasma aldosterone to ACTH (P less than 0.01) and upright posture (P less than 0.01) after fadrozole compared with placebo treatment further indicated that fadrozole impaired basal aldosterone secretion. This attenuation of aldosterone secretion was accompanied by a rise of PRA in the basal condition (P = 0.05) and after stimulation by 40 mg furosemide (P less than 0.01) and upright posture (P less than 0.01). An increase in deoxycorticosterone was observed after fadrozole treatment compared with pretreatment values (P less than 0.01) and after stimulation with ACTH compared with placebo (P less than 0.05). This study confirms that fadrozole given in daily doses of 4 mg is an effective aromatase inhibitor which does not affect glucocorticoid secretion. However, this dose may induce an impairment of aldosterone secretion which is modest and revealed mainly under specific stimulatory conditions, and does not lead to clinical symptoms of hemodynamic dysregulation or a relevant disturbance of serum electrolytes.

No abstract

We have demonstrated that the PAF antagonist BN 52021 can minimize the alteration of renal function induced by CsA.

Animals and humans undergoing treatment with ciclosporin (CS) show a reversible increase in renal vascular resistance and a decrease in glomerular filtration rate. The causes of these abnormalities have not yet been established. We evaluated the effects of a 1-week treatment with CS on creatinine clearance, renal arachidonic acid metabolites, plasma renin activity (PRA), plasma aldosterone levels, urinary excretion and plasma levels of catecholamines in 7 patients with idiopathic uveitis. We show that CS treatment induces a significant (p < 0.05) decrease in creatinine clearance (from 132 ± 0.5 to 108 ± 8 ml/min); urinary 6-keto-PGF₁ excretion (from 17.8 ± 4.9 to 10.9 ± 3.3 ng/mmol creatinine), urinary thromboxane B₂ excretion (from 7.0 ± 1.0 to 3.6 ± 0.9 ng/mmol creatinine), upright PRA (from 4.2 ± 0.9 to 2.3 ± 0.8) and supine PRA (from 2.0 ± 0.5 to 1.1 ± 0.3). We found no change in plasma aldosterone levels and plasma levels and urinary excretion of catecholamines. We suggest that the reversible renal vasoconstriction observed in patients treated with CS may be induced by inhibition of renal prostacyclin synthesis. In this setting inhibition of PRA and angiotensin II formation may impair autoregulation of effective filtration pressure and therefore glomerular filtration rate.