Effect of Testosterone Therapy on Concentration of Potassium in Serum. ∗

Abstract

In his pioneer investigations on perfusion fluids, Ringer observed that while the addition of potassium was not essential for the maintenance of the frog or turtle heart beat. a concentration of approximately 4 milli-equivalents per liter was one of the requisites of a solution providing optimal contractions. For the mammalian heart Locke designated the optimal potassium concentration of perfusion fluids at approximately 5.5 meq. per liter.

The observation that potassium salts relieved the paralysis of so-called familial periodic paralysis 1 2 3 4 5 6 and the more recent observation that a fall in serum potassium concentration was associated with the attacks of paralysis suggested a correlation between muscle weakness and serum potassium concentration. 2 3 4 5 6 During such attacks bradycardia, hypotension, arrhythmia and cardiac dilatation have been observed. However, though a fall in the serum potassium concentration occurs with such attacks, the specific concentration at which paralysis appears varies greatly. A somewhat similar concomitant decrease in serum potassium and in muscle strength has been observed following the administration of desoxycorticosterone acetate 7 8 9 10 11 12 13 and the skeletal muscle weakness and the heart failure that may occur with such therapy has been ascribed to these low serum concentrations. 9 , 11 , 13 , 14 On the other hand, low serum potassium levels may occur without paralysis or heart failure following the injection of insulin. 15 , 16

This paper reports the striking fall in serum potassium which we occasionally have observed in patients following the daily administration of either methyl testosterone by mouth or testosterone propionate intramuscularly.