Also Known As: Methenamine, Hexamethylenetetramine
Hexamethylenetetramine is a heterocyclic organic compound with the formula (CH2)6N4. This white crystalline compound is highly soluble in water and polar organic solvents. It has a cage-like structure similar to adamantane. It is useful in the synthesis of other chemical compounds, e.g. plastics, pharmaceuticals, rubber additives. It sublimes in a vacuum at 280 Â°C.
As the mandelic acid salt (generic methenamine mandelate tablets, USP ) it is used for the treatment of urinary tract infection: hexamethyltetramine ("methenamine") decomposes at an acid pH to formaldehyde and ammonia, and the formaldehyde is bactericidal; the mandelic acid adds to this effect. Urinary acidity is typically ensured by co-administering vitamin C (ascorbic acid) or ammonium chloride. Its use had temporarily been reduced in the late 1990s, due to adverse effects (notably chemically-induced hemorrhagic cystitis in overdose), but its use has now been reapproved because of the prevalence of antibiotic resistance to more commonly used drugs. This drug is particularly suitable for long-term prophylactic treatment of urinary tract infection, because bacteria do not develop resistance to formaldehyde: however, it should not be used in the presence of renal insufficiency.