Hexamethylenamina. The U. S. P. designation for hexa-methylene tetramin, an ammonia condensation product of formaldehyde. It is the same general type of product as are "Urotropin," "Fonnin," and "Cystogen." These products increase the excretion of urine and uric acid and carry an antiseptic direct into the urinary tract. The dose is from I to 10 gr. Average dose, 4 or 5 gr., dissolved in hot or carbonated water, after meals.