Drug General Information (ID: DDI0SO7RFT)
Drug Name			Amphetamine		Drug Info		Methenamine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Cns Stimulants				Urinary Antispasmodics
Structure

Mechanism of Amphetamine-Methenamine Interaction (Severity Level: Moderate)
Altered urine pH Click to Show/Hide Mechanism Graph
Drug Name		Amphetamine				Methenamine
Mechanism		Urine pH sensitive				Urine acidifier Increase the renal excretion
Key Mechanism Factor 1
		Factor Name		Urine pH
		Factor Description		The normal range of urine pH is between 4.5 and 8, depending mainly on the hydrogen ion concentration. Changes in urine pH may significantly affect drug reabsorption and excretion.
Mechanism Description		Altered elimination of Amphetamine caused by Methenamine mediated altered urine pH

Recommended Action
Management		Patients receiving an amphetamine in combination with urinary acidifying agents should be monitored for potentially diminished pharmacologic response to the amphetamine.

References
1	Beckett AH, Rowland M, Turner P "Influence of urinary pH on excretion of amphetamine." Lancet 1 (1965): 303. [PMID: 14247879]
2	Product Information. Dexedrine (dextroamphetamine) SmithKline Beecham, Philadelphia, PA.
3	Gary NE, Saidi P "Methamphetamine intoxication. A speedy new treatment." Am J Med 64 (1978): 537-40