Iboga + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine brand name: Colrex.
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls into 3 drug categories that Iboga can interact with; the most serious is rated moderate. Theoretically, taking iboga with serotonergic drugs might increase levels of serotonin, resulting in additive effects with serotonergic drugs.
Read the full interaction reportIboga and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
These two interact in 3 distinct ways. Each one is explained separately below.
Why Are There 3 Interactions?
Iboga interacts with whole categories of medication. Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls into 3 of those categories, so it can interact with Iboga in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
SEROTONERGIC DRUGS
1 of 3Why this applies to Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls under SEROTONERGIC DRUGS — the group Iboga interacts with.
Ibogaine, a constituent in iboga, has serotonergic effects. Theoretically, combining serotonergic drugs with iboga might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders. Monitor patients for signs of serotonin syndrome and other serotonergic side effects if using iboga with serotonergic drugs.
Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
The piece of this combination product that matters most here is the codeine. Codeine and the antihistamine chlorpheniramine both nudge serotonin activity in the brain. Iboga (through ibogaine) also raises serotonin. Stack them together and, in theory, you could push serotonin too high, which is what we call serotonin syndrome. Watch for agitation, a racing heart, sweating, shivering, muscle twitching, or confusion.
I want to be honest about the evidence: this concern is theoretical, based on how these substances work rather than real cases of this exact pairing. That said, Iboga carries serious heart rhythm risks on its own and is illegal here, so I would not combine them. Please run any plans past your pharmacist or doctor first.
- Glick SD, Maisonneuve IS. Mechanisms of antiaddictive actions of ibogaine. Ann N Y Acad Sci 1998;844:214-26.
- Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
- Litjens RP, Brunt TM. How toxic is ibogaine? Clin Toxicol (Phila). 2016;54(4):297-302. PubMed
ANTICHOLINERGIC DRUGS
2 of 3Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine also falls under ANTICHOLINERGIC DRUGS.
In vitro research shows that iboga can inhibit acetylcholinesterase and might increase acetylcholine levels. However, the constituent ibogaine does not appear to have this effect.
Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
This combo product (Colrex) includes chlorpheniramine, an antihistamine with drying, anticholinergic effects, meaning it blocks the messenger acetylcholine. The concern here is theoretical: lab studies suggest Iboga may raise acetylcholine levels, which could push back against chlorpheniramine and make it work less well. In real terms, that might mean less relief from a runny nose or sneezing. Keep in mind this is based only on test-tube research, and the main compound in Iboga (ibogaine) did not show this effect, so the practical risk is unclear.
Honestly, my bigger worry is safety: Iboga is illegal in the U.S. and can cause dangerous heart rhythm problems, and your product also contains codeine. Please talk with your pharmacist or doctor before mixing anything with Iboga.
- Alper K, Reith ME, Sershen H. Ibogaine and the inhibition of acetylcholinesterase. J Ethnopharmacol. 2012;139(3):879-82. PubMed
CYTOCHROME P450 2D6 (CYP2D6) INHIBITORS
3 of 3Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine also falls under CYTOCHROME P450 2D6 (CYP2D6) INHIBITORS.
Ibogaine, the active constituent of iboga, is a substrate of CYP2D6. One pharmacokinetic study shows that taking the CYP2D6 inhibitor paroxetine prior to taking ibogaine 20 mg increases the exposure to ibogaine and its metabolite noribogaine by 2-fold when compared with ibogaine alone.
Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
Here is the twist with this combination. Your cold and cough product (Colrex) contains codeine, which leans on the liver enzyme CYP2D6 to turn into morphine, the part that actually relieves pain and quiets a cough. The chlorpheniramine in this product can mildly block that same enzyme. The bigger point in the file, though, runs the other direction: ibogaine itself is broken down by CYP2D6, so anything that blocks that enzyme can let ibogaine pile up to roughly double levels, raising its risk of dangerous heart rhythm changes.
This is largely theoretical, and Iboga is not a safe or legal supplement here. Please don't combine them, and check with your pharmacist or doctor first.
- Henstra M, Wong L, Chahbouni A, et al. Toxicokinetics of ibogaine and noribogaine in a patient with prolonged multiple cardiac arrhythmias after ingestion of internet purchased ibogaine. Clin Toxicol (Phila). 2017;55(6):600-602. PubMed
- Glue P, Winter H, Garbe K, et al. Influence of CYP2D6 activity on the pharmacokinetics and pharmacodynamics of a single 20?mg dose of ibogaine in healthy volunteers. J Clin Pharmacol. 2015;55(6):680-7. PubMed
- Rodriguez P, Urbanavicius J, Prieto JP, et al. A single administration of the atypical psychedelic ibogaine or its metabolite noribogaine induces an antidepressant-like effect in rats. ACS Chem Neurosci 2020;11(11):1661-1672. PubMed
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
- ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
- PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
- UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
- AHigh-quality meta-analysis (quantitative systematic review).
- BCase-control study.
- CConsensus.
- DAnecdotal evidence.
These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.
Iboga Also Interacts With Other Medications
Iboga has 1 major, 500 moderate known drug interactions in our database — the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Iboga
We haven’t checked that one against Iboga yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Iboga. Pick one to open its full report.
See Every Supplement That Interacts With Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
This page covers Iboga only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine page lists 338 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Ephedra (major).
By severity: 18 major · 275 moderate · 45 minor.
From our pharmacist’s overview on the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine page
“Someone taking Colrex is usually fighting a miserable cold, and cold season is also when people reach for herbal sleep aids and energy boosters, which is exactly where this list bites hardest. Colrex combines acetaminophen, chlorpheniramine, codeine, and phenylephrine, and 18 of its 338 supplement interactions rate major, enough to war…”
Reviewed by 2 · Jul 18, 2026
Open the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction page
Where Iboga and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#622 of 1,452 supplements looked up here in the last 7 days
#305 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
About Iboga
What is Iboga?
- Drug and alcohol addiction
- Opioid withdrawal
- Spiritual and ceremonial rituals
- Fatigue and stimulant effects
- Mood and emotional issues
Iboga is a Central African shrub whose root bark contains ibogaine, a powerful hallucinogenic compound studied mainly for addiction. It carries serious safety risks, including dangerous heart rhythm changes and deaths, and ibogaine is illegal in the United States and many other countries. We do not recommend its use outside of tightly controlled research settings.
Other Drugs & Iboga
Browse every other medication we’ve checked against Iboga — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1 interaction
500 interactions
- Metronidazole ›
- Diphenhydramine ›
- Methylphenidate ›
- Erythromycin ›
- Ranitidine ›
- Quinidine ›
- Glycopyrrolate ›
- Bupropion ›
- Chloroquine ›
- Fentanyl ›
- Oxybutynin ›
- Tacrolimus ›
- Carbamazepine ›
- Dextromethorphan ›
- Ipratropium ›
- Phenylephrine ›
- Procainamide ›
- Trimipramine ›
- Buprenorphine ›
- Dimenhydrinate ›
- Everolimus ›
- Lofepramine ›
- Nortriptyline ›
- Pilocarpine ›
- Procyclidine ›
- Propoxyphene ›
- Selegiline ›
- Sotalol ›
- Sumatriptan Succinate ›
- Amantadine ›
- Aripiprazole ›
- Azithromycin ›
- Cimetidine ›
- Cyclobenzaprine ›
- Desipramine ›
- Doxepin ›
- Duloxetine ›
- Edrophonium ›
- Erythromycin Ethylsuccinate ›
- Erythromycin Stearate ›
- Fluphenazine ›
- Hydroxyzine ›
- Hyoscyamine ›
- Levofloxacin ›
- Meclizine ›
- Metoclopramide ›
- Nicardipine ›
- Phenobarbital ›
- Prucalopride ›
- Scopolamine ›
- Tramadol ›
- Trihexyphenidyl ›
- Trospium ›
- Valproic Acid ›
- Vortioxetine ›
- Abiraterone Acetate ›
- Almotriptan ›
- Amiodarone ›
- Aripiprazole Lauroxil ›
- Artemether ›
Showing 60 of 500 moderate interactions — see all 500 on the Iboga page.
No interaction 2,328 drugs checked — show the list
We also checked Iboga against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Warfarin ›
- Abemaciclib ›
- Ivermectin ›
- Testosterone ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Clopidogrel ›
- Rivaroxaban ›
- Atorvastatin ›
- Isotretinoin ›
- Tirzepatide ›
- Warfarin Sodium ›
- Ibuprofen ›
- Amlodipine Besylate ›
- Docusate ›
- Valacyclovir ›
- Tadalafil ›
- Hydroxyurea ›
- Prednisone ›
- Metformin ›
- Semaglutide ›
- Propranolol ›
- Amphetamine ›
- Amoxicillin ›
- Methotrexate ›
- Lisinopril ›
- Levothyroxine, Liothyronine ›
- Bendamustine ›
- Pregabalin ›
- Doxycycline ›
- Lamotrigine ›
- Gabapentin ›
- Acyclovir ›
- Naproxen ›
- Clonazepam ›
- Acetaminophen, Aspirin, Caffeine ›
- Omeprazole ›
- Letrozole ›
- Acetaminophen, Codeine ›
- Ciprofloxacin ›
- Candesartan Cilexetil ›
- Amoxicillin, Clavulanate Potassium ›
- Acetaminophen, Butalbital, Caffeine ›
- Bisoprolol ›
- Acetylsalicylic Acid ›
- Acetaminophen, Aspirin ›
- Acetaminophen, Caffeine, Codeine ›
- Acetaminophen, Oxycodone ›
- Diazepam ›
- Amlodipine Besilate ›
- Perindopril Arginine, Amlodipine ›
- Calcium Oxybate, Magnesium Oxybate, Potassium Oxybate, Sodium Oxybate ›
- Insulin Degludec, Liraglutide ›
- Ezetimibe ›
Showing the 60 most looked-up of 2,328 medications checked with no known interaction — see the full Iboga list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine Is Linked to Lower Levels of One Nutrient
Natural Medicines records Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine as a medicine that can lower these. This is not an interaction with Iboga — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Iboga and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine Together: Common Questions
Can you take Iboga with Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine?
Why are there 3 interactions listed for Iboga and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine?
How serious is the Iboga and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.