Drug General Information (ID: DDIA53CGUH)
Drug Name			Zonisamide		Drug Info		Chlorcyclizine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Analgesics				Antihistamines
Structure

Mechanism of Zonisamide-Chlorcyclizine Interaction (Severity Level: Major)
Additive CNS depression effects Click to Show/Hide Mechanism Graph
Drug Name		Zonisamide				Chlorcyclizine
Mechanism 1		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 Zonisamide and Chlorcyclizine
Increased risk of hyperpyrexia Click to Show/Hide Mechanism Graph
Drug Name		Zonisamide				Chlorcyclizine
Mechanism 2		Hyperpyrexia				Hyperpyrexia
Key Mechanism Factor 2
		Factor Name		Hyperpyrexia
		Factor Description		Hyperthermia is an extreme, life-threatening increase in core body temperature. If hyperthermia persists for a long time or worsens, more serious symptoms may occur, such as confusion, headache, constricted pupils, vomiting, diarrhea, and decreased urine output.
Mechanism Description		Increased risk of hyperpyrexia by the combination of Zonisamide and Chlorcyclizine

Recommended Action
Management		Caution is advised when zonisamide is prescribed with other drugs that predispose patients to heat-related disorders, including carbonic anhydrase inhibitors and drugs with anticholinergic activity. Patients, particularly pediatric patients, should be monitored closely for evidence of decreased sweating and increased body temperature, especially in warm or hot weather. Proper hydration before and during vigorous activities or exposure to warm temperatures is recommended. Patients (or their guardians or caregivers) should contact their physician immediately if they are not sweating as usual, with or without a fever. Ambulatory patients treated with zonisamide and agents with anticholinergic activity should also be made aware of the possibility of additive CNS effects (e.g., drowsiness, dizziness, lightheadedness, confusion) and counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References
1	Product Information. Zonegran (zonisamide) Elan Pharmaceuticals, S. San Francisco, CA.