Digitoxicity related to magnesium levels

Aim: to find the relationship between Magnesium levels and patients who are digoxin therapy and correlated with those who developed digitoxicity. Methods: Eighty-one hospital patients receiving digoxin were separated into groups with and without digitoxicity (digoxin toxicity) using clinical criteria. Serum digoxin, sodium, potassium, calcium, creatinine, magnesium and monocyte magnesium concentrations were compared. Subjects with digoxin toxicity had impaired colour vision (P < 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 I-1, P < 0.01) (mean (95% confidence limits)), though there was considerable overlap between the two groups. Results: Subjects with digoxin toxicity had lower levels of serum magnesium (0.80 (0.76-0.84) vs 0.88 (0.85-0.91) mmol 1-1, P < 0.01) and monocyte magnesium (6.40 (5.65-7.16) vs 8.76 (7.81-9.71) mg g-1 DNA, P < 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 < 0.05). Conclusion: Magnesium deficiency was the most frequently identified significant electrolyte disturbance in relation to digoxin toxicity. (Young et al., 1991) In the presence of magnesium deficiency digoxin toxicity developed at relatively low serum digoxin concentrations.