Clonidine and Zonisamide interaction
Clonidine and Zonisamide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Clonidine (QLONILIK) label · effective 2026-08-12
Avoid use with other central nervous system (CNS) depressants ( 5.3 )
Avoid use with other central nervous system (CNS) depressants, as this combination may cause excessive drowsiness or sedation [see Drug Interactions (7) ].
From the Zonisamide (ZONISADE) label · effective 2025-09-08
Patients should be carefully observed for signs of central nervous system (CNS) depression, such as somnolence and sedation, when ZONISADE is used with other drugs with sedative properties because of potential additive effects.
• ZONISADE should be used with caution if used in combination with alcohol or other CNS depressants ( 7.1 ).
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.