Drug General Information (ID: DDI5TFICKX)
Drug Name			Hydroxychloroquine		Drug Info		Magnesium hydroxide		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antimalarial Agents				Antacids/Laxatives
Structure

Mechanism of Hydroxychloroquine-Magnesium hydroxide Interaction (Severity Level: Moderate)
Complex formation Click to Show/Hide Mechanism Graph
Drug Name		Hydroxychloroquine				Magnesium hydroxide
Mechanism		Binds to polyvalent cations				Polyvalent cations
Key Mechanism Factor 1
		Factor Name		Chelation
		Factor Description		Chelation is a direct drug interaction that usually involves the formation of dimers or trimers, resulting in larger complexes and poorer absorption.
Mechanism Description		Decreased absorption of Magnesium hydroxide due to formation of complexes caused by Hydroxychloroquine

Recommended Action
Management		Chloroquine product labeling suggests separating the doses by at least 4 hours if concomitant therapy with antacids or kaolin is required. The same precaution may be applicable to hydroxychloroquine, although no data are available to support this recommendation. Some authorities recommend separating the dose of hydroxychloroquine from antacids and kaolin by at least 2 hours (AU).

References
1	Cerner Multum, Inc. "Australian Product Information.".
2	Cerner Multum, Inc. "UK Summary of Product Characteristics.".
3	D'Arcy PF, McElnay JC "Drug-antacid interactions: assessment of clinical importance." Drug Intell Clin Pharm 21 (1987): 607-17. [PMID: 2886325]
4	Iwuagwu MA, Aloko KS "Adsorption of paracetamol and chloroquine phosphate by some antacids." J Pharm Pharmacol 44 (1992): 655-8. [PMID: 1359089]
5	McElnay JC, Mukhtar HA, Arcy PF, Temple DJ "In vitro experiments on chloroquine and pyrimethamine absorption in the presence of antacid constituents or kaolin." J Trop Med Hyg 85 (1982): 153-8. [PMID: 7143531]
6	McElnay JC, Mukhtar HA, D'Arcy PF, Temple DJ, Collier PS "The effect of magnesium trisilicate and kaolin on the in vivo absorption of chloroquine." J Trop Med Hyg 85 (1982): 159-63. [PMID: 6292443]
7	Product Information. Aralen (chloroquine). Sanofi Winthrop Pharmaceuticals, New York, NY.
8	Wallace AW, Amsden GW "Is it really OK to take this with food? Old interactions with a new twist." J Clin Pharmacol 42 (2002): 437-43. [PMID: 11936569]