Hypertension in cyclosporine-treated renal transplant recipients is sodium dependent

Physicians increasingly prescribe cyclosporine as an immunosuppressive agent for both organ-transplant and non-organ-transplant recipients. Investigators have reported a high incidence of drug-induced hypertension even when clinical nephrotoxicity was not present. We wanted to determine the reason.

A comparison was made of hypertension in 15 cyclosporine-treated transplant recipients with that in a similar group of 15 azathioprine-treated transplant recipients.

Hypertension in the cyclosporine group responded differently from that seen in the azathioprine group and from previously described forms of post-transplantation hypertension. Hypertensive cyclosporine-treated patients show a sodium acquisitive renal state that responds to sodium restriction. Unlike rat models, which suggest cyclosporine-induced stimulation of the renin-angiotensin system, or previous forms of post-transplant hypertension in humans, plasma renin levels were not elevated and blood pressure did not respond to a test dose of captopril.

Hypertension in cyclosporine-treated patients is an iatrogenic form of hypertension that may be associated with an early, subtle, renal defect in sodium excretion, a genesis of hypertension that is consistent with Guyton's view of essential hypertension.