FURTHER STUDIES ON THE ABSORPTION OF MERCURIAL DIURETICS AS INFLUENCED BY THEOPHYLLINE AND OTHER SUBSTANCES

¹ From the Department of Therapeutics, New York University College of Medicine

1. Theophylline has been shown to increase the absorption of Mercurin and Salyrgan from the site of intramuscular injection in proportion to the amount present. One mole equivalent produces complete absorption after 55 minutes.

2. Succinimide, uracil, hydantoin, ammonium chloride and glycine have all been found to improve the absorption of Mercurin but in decreasing order of effectiveness.

3. It has been demonstrated that part of the ability of these "protective agents" to enhance absorption lies in the reduction of the pH of the solution to more nearly that of blood.

4. The absorption of Mercupurin (Mercurin with theophylline) has been found to decrease 22 per cent upon an increase in the pH from 8.8 to 9.7. It would therefore be advisable to administer Mercupurin in a solution whose pH is below 8.5.

5. The possibility of Mercurin and Salyrgan forming slightly ionized compounds with theophylline and perhaps with the other compounds of similar structure is discussed.