Drug interactions
Cocaine + Phenylephrine
Severity: Major
Cocaine and Phenylephrine: 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
Cocaine combined with phenylephrine can cause additive vasoconstriction and pressor effects, increasing the risk of severe hypertension, myocardial ischemia and arrhythmia.
What this interaction means in plain words
Cocaine and Phenylephrine 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.
Cocaine belongs to Central Nervous System; Phenylephrine belongs to Respiratory.
Why it happens
Additive sympathomimetic effects: cocaine reuptake blockade plus alpha-1 agonism.
What to do
Avoid additional vasoconstrictors where possible. If unavoidable, use the lowest dose with prolonged ECG and blood pressure monitoring.
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 Cocaine
- Cocaine + Isocarboxazid Contraindicated
- Cocaine + Phenelzine Contraindicated
- Cocaine + Procarbazine Contraindicated
- Amitriptyline + Cocaine Major
- Bisoprolol + Cocaine Major
- Citalopram + Cocaine Major
Other interactions of Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
- Dihydroergotamine + Phenylephrine Major
Frequently asked questions
Can I take Cocaine with Phenylephrine?
MediHelp rates the interaction as major. Cocaine and Phenylephrine 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. Cocaine combined with phenylephrine can cause additive vasoconstriction and pressor effects, increasing the risk of severe hypertension, myocardial ischemia and arrhythmia.
How serious is the interaction between Cocaine and Phenylephrine?
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 additional vasoconstrictors where possible. If unavoidable, use the lowest dose with prolonged ECG and blood pressure monitoring.
What other medicines interact with Cocaine?
MediHelp also lists interactions of Cocaine with, for example, Isocarboxazid, Phenelzine, Procarbazine. The full list is on the Cocaine page.
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