The normal kidney is able to maintain its function in the face of renal injury and overt abnormalities are not seen until at least 50% of filtration capacity is lost. Progressive renal damage can occur from glomerular disease, tubulointerstitial disease, or chronic obstructive pathology. Major effects of renal failure include electrolyte and volume imbalance, anemia, and bone disease.

Common causes of CKD in the United States are hypertension and diabetes followed by glomerulonephritis. There are various immunologic, infectious, and vascular diseases as well as drugs that can cause CKD.

See Chapter 1 for recommendations on using psychotropic medications in preexisting renal disease. Following is a review of psychotropic-induced renal failure.

Among psychotropic medications, lithium is implicated in CKD. The exact magnitude of risk of CKD with lithium use is uncertain but is estimated to be small. There is a reduction of glomerular filtration rate (GFR) , an estimate of kidney function, over time with lithium . However, the absolute risk of end-stage failure is thought to be only about 0.5%, which is slightly higher than the general population [1]. Lithium’s adverse effect on kidney function is mainly via interstitial injury and to a smaller extent, glomerular injury. Lithium causes renal tubular dysfunction and concentrating deficit earlier in treatment (see Chapter 15) but lithium-induced nephropathy results from chronic use.

Duration of lithium use is linked to risk of CKD. It is estimated that it takes 10–20 years for lithium-induced kidney damage to progress to kidney failure [2]. High lithium dosages are also thought to increase the risk. Dosing lithium multiple times during the day increases the risk compared to once-daily dosing. Episodes of lithium toxicity predispose to development of chronic renal failure. In addition to overdose, risks for nephrotoxicity include advanced age, other medications that affect renal function, other medical conditions that can cause CKD, decreased circulating volume, and diabetes insipidus that is also a side effect of lithium (see Chapter 15).