Drug General Information (ID: DDIQCM1O54)
Drug Name			Magnesium hydroxide		Drug Info		Velpatasvir		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antacids/Laxatives				Antiviral Agents
Structure

Mechanism of Magnesium hydroxide-Velpatasvir Interaction (Severity Level: Moderate)
Altered gastric pH Click to Show/Hide Mechanism Graph
Drug Name		Magnesium hydroxide				Velpatasvir
Mechanism		Gastric alkalinizer				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 Velpatasvir due to altered gastric pH caused by Magnesium hydroxide

Recommended Action
Management		If an antacid is required, the antacid should be taken 4 hours before or 4 hours after administration of sofosbuvir-velpatasvir. The same precaution may be applicable to other drugs with antacid effects.

References
1	Product Information. Epclusa (sofosbuvir-velpatasvir). Gilead Sciences, Foster City, CA.