Clonidine and Protriptyline interaction
Clonidine and Protriptyline: 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) ].
Tricyclic antidepressants Clinical Implication Concomitant use of tricyclic antidepressants with clonidine can increase blood pressure and may counteract the hypotensive effects of clonidine.
Concomitant use of tricyclic antidepressants with clonidine can increase blood pressure and may counteract the hypotensive effects of clonidine.
From the Protriptyline (Protriptyline Hydrochloride) label · effective 2023-07-25
Protriptyline may enhance the response to alcohol and the effects of barbiturates and other CNS depressants.
Protriptyline may block the antihypertensive effect of guanethidine or similarly acting compounds.
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.