Drug interactions
Cimetidine + Pentoxifylline
Severity: Minor
Cimetidine and Pentoxifylline: minor 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
Cimetidine may increase pentoxifylline and its metabolite levels. This could increase adverse effects such as nausea, dizziness, flushing or hypotension.
What this interaction means in plain words
Cimetidine and Pentoxifylline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Cimetidine belongs to Gastrointestinal Tract; Pentoxifylline belongs to Cardiovascular.
Why it happens
Cimetidine inhibits CYP1A2-mediated metabolism of pentoxifylline.
What to do
Monitor for gastrointestinal and cardiovascular adverse effects, and reduce the pentoxifylline dose if they occur.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Pentoxifylline
- Amifostine + Pentoxifylline Moderate
- Fluoxetine + Pentoxifylline Moderate
- Fluvoxamine + Pentoxifylline Moderate
- Insulin degludec / insulin aspart + Pentoxifylline Moderate
- Methoxsalen + Pentoxifylline Moderate
- Mexiletine + Pentoxifylline Moderate
Frequently asked questions
Can I take Cimetidine with Pentoxifylline?
MediHelp rates the interaction as minor. Cimetidine and Pentoxifylline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cimetidine may increase pentoxifylline and its metabolite levels. This could increase adverse effects such as nausea, dizziness, flushing or hypotension.
How serious is the interaction between Cimetidine and Pentoxifylline?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for gastrointestinal and cardiovascular adverse effects, and reduce the pentoxifylline dose if they occur.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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