Drug interactions
Clarithromycin + Guanfacine
Severity: Moderate
Clarithromycin and Guanfacine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Clarithromycin markedly increases guanfacine concentrations, which can cause bradycardia, hypotension and excessive sedation.
What this interaction means in plain words
Clarithromycin and Guanfacine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Clarithromycin belongs to Anti Bacterial; Guanfacine belongs to Cardiovascular.
Why it happens
Inhibition of CYP3A4 reduces guanfacine clearance.
What to do
Halve the extended-release guanfacine dose during co-administration and monitor heart rate, blood pressure and sedation.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Guanfacine
- Clonidine + Guanfacine Major
- Guanfacine + Lofexidine Major
- Aldesleukin + Guanfacine Moderate
- Amiodarone + Guanfacine Moderate
- Amisulpride + Guanfacine Moderate
- Amitriptyline + Guanfacine Moderate
Frequently asked questions
Can I take Clarithromycin with Guanfacine?
MediHelp rates the interaction as moderate. Clarithromycin and Guanfacine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Clarithromycin markedly increases guanfacine concentrations, which can cause bradycardia, hypotension and excessive sedation.
How serious is the interaction between Clarithromycin and Guanfacine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Halve the extended-release guanfacine dose during co-administration and monitor heart rate, blood pressure and sedation.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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