Drug General Information (ID: DDINIBUJ7Q)
Drug Name			Cetirizine		Drug Info		St. John's Wort		Drug Info
Drug Type		Small molecule				Natural product
Therapeutic Class		Antiallergic Agents				Herbal Products/Antidepressants

Mechanism of Cetirizine-St. John's Wort Interaction (Severity Level: Moderate)
Additive CNS depression effects Click to Show/Hide Mechanism Graph
Drug Name		Cetirizine				St. John's Wort
Mechanism		CNS depression effects				CNS depression effects
Key Mechanism Factor 1
		Factor Name		CNS depression effects
		Factor Description		CNS depressants are drugs that inhibit or suppress brain activity and can reduce mental and physical processes. Excessive CNS depression can lead to decreased heart rate, slow breathing (less than 10 breaths per minute), extreme confusion or loss of memory, nausea and vomiting, poor judgment, blue lips or fingertips, irritability and aggression, and clammy or cold skin.
Mechanism Description		Additive CNS depression effects by the combination of Cetirizine and St. John's Wort

Recommended Action
Management		Concomitant use of cetirizine or levocetirizine with alcohol or other CNS depressants should generally be avoided if possible. In the event that they are used together, patients should be counseled against driving, operating machinery, or engaging in potentially hazardous activities requiring mental alertness and motor coordination.

References
1	Product Information. Zyrtec (cetirizine). Pfizer US Pharmaceuticals, New York, NY.
2	Product Information. Xyzal (levocetirizine). UCB Pharma Inc, Smyrna, GA.