Drug General Information (ID: DDIWS5FNB0)
Drug Name			Ascorbic acid		Drug Info		Metamfetamine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Vitamins				Cns Stimulants
Structure

Mechanism of Ascorbic acid-Metamfetamine Interaction (Severity Level: Moderate)
Altered gastric pH Click to Show/Hide Mechanism Graph
Drug Name		Ascorbic acid				Metamfetamine
Mechanism		Gastric acidifier				Gastric pH sensitive
Key Mechanism Factor 1
		Factor Name		Gastric pH
		Factor Description		The normal pH range of gastric acid is between 1.5 and 3.5 and is highly acidic, consisting mainly of hydrochloric acid. Changes in the pH of the stomach can alter the absorption of drugs.
Mechanism Description		Decreased absorption of Metamfetamine due to altered gastric pH caused by Ascorbic acid

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

References
1	Mendelson J, Jones RT, Upton R, Jacob P 3rd "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther 57 (1995): 559-68. [PMID: 7768079]
2	Product Information. Dexedrine (dextroamphetamine) SmithKline Beecham, Philadelphia, PA.
3	Product Information. Didrex (benzphetamine) Pharmacia and Upjohn, Kalamazoo, MI.