Chlorpromazine and Lofexidine interaction
Chlorpromazine and Lofexidine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Lofexidine label · effective 2026-07-22
Risk of QT Prolongation : Lofexidine tablets prolong the QT interval.
Increased Risk of CNS Depression with Concomitant use of CNS Depressant Drugs : Lofexidine tablets potentiates the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs.
Risk of QT Prolongation Lofexidine tablets prolong the QT interval.
Increased Risk of Central Nervous System Depression with Concomitant use of CNS Depressant Drugs Lofexidine tablets potentiates the CNS depressive effects of benzodiazepines and can also be expected to potentiate the CNS depressive effects of alcohol, barbiturates, and other sedating drugs.
Methadone : Methadone and Lofexidine tablets both prolong the QT interval.
From the Chlorpromazine (Chlorpromazine Hydrochloride) label · effective 2026-02-02
Chlorpromazine may counteract the antihypertensive effect of guanethidine and related 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.