title: Magnesium status and digoxin toxicity.
abstract: 1. Eighty-one hospital patients receiving digoxin were separated into groups with and without digoxin toxicity using clinical criteria. Serum digoxin, sodium, potassium, calcium, creatinine, magnesium and monocyte magnesium concentrations were compared. 2. Subjects with digoxin toxicity had impaired colour vision (P less than 0.0001, Farnsworth-Munsell 100 hue test) and increased digoxin levels (1.89 (1.56-2.21) vs 1.34 (1.20-1.47) nmol l-1, P less than 0.01) (mean (95% confidence limits], though there was considerable overlap between two groups. 3. Subjects with digoxin toxicity had lower levels of serum magnesium (0.80 (0.76-0.84) vs 0.88 (0.85-0.91) mmol l-1, P less than 0.01) and monocyte magnesium (6.40 (5.65-7.16) vs 8.76 (7.81-9.71) mg g-1 DNA, P less than 0.01), but there were no significant differences in other biochemical parameters. A greater proportion of toxic subjects were receiving concomitant diuretic therapy (20/21 vs 37/60, P less than 0.05). 4. Magnesium deficiency was the most frequently identified significant electrolyte disturbance in relation to digoxin toxicity. In the presence of magnesium deficiency digoxin toxicity developed at relatively low serum digoxin concentrations.
authors.affiliation: Department of Clinical Biochemistry, Royal Victoria Hospital, Belfast.
authors.forename: I S
authors.initials: IS
authors.lastname: Young
authors.forename: E M
authors.initials: EM
authors.lastname: Goh
authors.forename: U H
authors.initials: UH
authors.lastname: McKillop
authors.forename: C F
authors.initials: CF
authors.lastname: Stanford
authors.forename: D P
authors.initials: DP
authors.lastname: Nicholls
authors.forename: E R
authors.initials: ER
authors.lastname: Trimble
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003117:Color Vision Defects / Q000209:etiology; D004077:Digoxin / Q000009:adverse effects* / Q000097:blood; D004573:Electrolytes / Q000097:blood; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008275:Magnesium Deficiency / Q000139:chemically induced* / Q000150:complications; D008297:Male; D008875:Middle Aged
chemical_list: D004573:Electrolytes; D004077:Digoxin; D008274:Magnesium