Drug interactions
Fentanyl iontophoretic transdermal system + Pentazocine
Severity: Major
Fentanyl iontophoretic transdermal system and Pentazocine: major 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
Pentazocine may compete with fentanyl at mu receptors, weakening analgesia and possibly precipitating withdrawal in opioid-tolerant patients. In patients who are not tolerant, the two drugs add to sedation and respiratory depression.
What this interaction means in plain words
Fentanyl iontophoretic transdermal system and Pentazocine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Mixed agonist-antagonist activity of pentazocine at opioid receptors combined with additive CNS depression.
What to do
Avoid concurrent use; choose one opioid regimen. If both are given, monitor sedation, respiratory rate and withdrawal symptoms closely.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Pentazocine
- Calcium / magnesium / potassium / sodium oxybates + Pentazocine Contraindicated
- Olanzapine / samidorphan + Pentazocine Contraindicated
- Pentazocine + Phenelzine Contraindicated
- Pentazocine + Tranylcypromine Contraindicated
- Alfentanil + Pentazocine Major
- Alprazolam + Pentazocine Major
Frequently asked questions
Can I take Fentanyl iontophoretic transdermal system with Pentazocine?
MediHelp rates the interaction as major. Fentanyl iontophoretic transdermal system and Pentazocine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Pentazocine may compete with fentanyl at mu receptors, weakening analgesia and possibly precipitating withdrawal in opioid-tolerant patients. In patients who are not tolerant, the two drugs add to sedation and respiratory depression.
How serious is the interaction between Fentanyl iontophoretic transdermal system and Pentazocine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use; choose one opioid regimen. If both are given, monitor sedation, respiratory rate and withdrawal symptoms closely.
What other medicines interact with Pentazocine?
MediHelp also lists interactions of Pentazocine with, for example, Calcium / magnesium / potassium / sodium oxybates, Olanzapine / samidorphan, Phenelzine. The full list is on the Pentazocine page.
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