Penetration of digoxin into cerebrospinal fluid G . D . SCHOTT

Introduction The importance of the cardiac glycosides in the treatment of a variety of heart diseases is firmly established and, although therapeutic problems remain, they are diminished by measurement of plasma levels of these drugs (Editorial, 1975). There has, however, been recent interest in the potential use of cardiac glycosides in neurological practice, including treatment of hydrocephalus (Neblett et al., 1972), benign intracranial hypertension (Schott and Holt, 1974) and mania (Naylor et al., 1975). Whilst CSF secretion by the choroid plexus may be influenced by these glycosides (Davson, 1967), effects resulting from the presence of digoxin in brain and CSF have also been proposed as a rationale for some of these therapeutic attempts, although the degree of penetration of these drugs remains controversial. The concentration of digoxin has therefore been investigated in the CSF of patients given this drug orally in doses resulting in plasma levels within the therapeutic range found useful in clinical cardiac practice.