Drug & supplement interaction

Rauvolfia Vomitoria + Morphine Sulfate

Morphine Sulfate brand names: MS Contin, Kadian, Avinza, Morphabond, Arymo ER.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Morphine Sulfate falls into 2 drug categories that Rauvolfia Vomitoria can interact with; the most serious is rated moderate. Theoretically, taking Rauvolfia vomitoria might cause additive sedative effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Rauvolfia Vomitoria and Morphine Sulfate

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Rauvolfia Vomitoria interacts with whole categories of medication. Morphine Sulfate falls into 2 of those categories, so it can interact with Rauvolfia Vomitoria in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CNS DEPRESSANTS

1 of 2

Why this applies to Morphine Sulfate

Morphine Sulfate falls under CNS DEPRESSANTS — the group Rauvolfia Vomitoria interacts with.

Theoretically, taking Rauvolfia vomitoria might cause additive sedative effects.
Rauvolfia vomitoria has sedative effects in animal research.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version. Morphine already calms the nervous system to ease pain, and it can leave you drowsy, foggy, or with slowed breathing. Rauvolfia vomitoria has shown its own sedating, calming effects in animal studies, so the concern is that the two together could pile on top of each other and make you sleepier or more sluggish than expected.

I'll be honest about the strength here: this is a theoretical concern based on how these substances behave, not something proven in people. Morphine is not a prodrug, so this isn't about one activating the other, it's just two relaxing agents stacking up. Even so, with an opioid, extra sedation matters. Please check with your doctor or pharmacist before combining them, and watch for unusual drowsiness or slowed breathing.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ekong MB, Peter AI, Edagha IA, et al. Rauwolfia vomitoria inhibits olfaction and modifies olfactory bulb cells. Brain Res Bull 2016;124:206-13. PubMed
  2. Amole OO, Yemitan OK, Oshikoya KA. Anticonvulsant activity of Rauvol?a Vomitoria (Afzel). Afr J Pharmacy Pharmacol 2009;3:319-322.
  3. Campbell JI, Mortensen A, Mølgaard P. Tissue lipid lowering-effect of a traditional Nigerian anti-diabetic infusion of Rauwolfia vomitoria foilage and Citrus aurantium fruit. J Ethnopharmacol 2006;104:379-86. PubMed
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 2

Morphine Sulfate also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Theoretically, Rauvolfia vomitoria might increase the levels and clinical effects of CYP2D6 substrates.
Rauvolfia vomitoria contains small amounts of the drug yohimbine. In vitro research shows that yohimbine inhibits CYP2D6 enzyme activity.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing about morphine and Rauvolfia vomitoria: the connection on file is pretty weak. The concern is that this plant contains a little yohimbine, and in lab (test tube) studies, yohimbine can slow down a liver enzyme called CYP2D6. The worry is that blocking that enzyme could let drugs cleared by it build up.

But morphine actually leans only lightly on CYP2D6, so this is mostly theoretical for morphine and based on lab data, not real patients. If levels did creep up, you'd watch for the usual opioid effects getting stronger, like extra drowsiness, slowed breathing, constipation, or feeling foggy. Rauvolfia can also drop your blood pressure on its own. Please loop in your doctor or pharmacist before combining these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. VandenBrink, B. M., Foti, R. S., Rock, D. A., Wienkers, L. C., and Wahlstrom, J. L. Prediction of CYP2D6 drug interactions from in vitro data: evidence for substrate-dependent inhibition. Drug Metab Dispos. 2012;40(1):47-53. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • 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.
Evidence the quality of the studies behind the rating (graded A–D)
  • 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.

Keep it in perspective

Rauvolfia Vomitoria Also Interacts With Other Medications

Rauvolfia Vomitoria has 230 major, 522 moderate, 87 minor known drug interactions in our database — the Morphine Sulfate one above is among them. If you take anything else, check it against the full list below.

Major 230 Moderate 522 Minor 87 No known interaction 1,991 (incl. Morphine Sulfate)
Taking anything else?

Check Another of Your Medications Against Rauvolfia Vomitoria

Covers the 2,830 medications we’ve checked against Rauvolfia Vomitoria. Pick one to open its full report.

From our Q&A

Questions About Rauvolfia Vomitoria or Morphine Sulfate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Rauvolfia Vomitoria or Morphine Sulfate, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Morphine Sulfate

This page covers Rauvolfia Vomitoria only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Morphine Sulfate page lists 172 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), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 8 major · 138 moderate · 26 minor.

From our pharmacist’s overview on the Morphine Sulfate page

“With morphine sulfate (MS Contin, Kadian, Avinza), an opioid powerful enough to slow breathing on its own, this list warrants genuine respect. Of the 172 supplements and foods on file, 8 carry a major rating, and most of those pile extra sedation onto a drug that already sedates.”

Reviewed by 2 · Jul 18, 2026

Open the Morphine Sulfate interaction page

One more smart check

Taking Rauvolfia Vomitoria as Part of a Dietary Supplement Product? Check It for Interactions

We hold 17 real supplement products containing Rauvolfia Vomitoria, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Rauvolfia Vomitoria. Your product may carry other ingredients that interact with Morphine Sulfate too, on top of Rauvolfia Vomitoria — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Rauvolfia Vomitoria and Morphine Sulfate 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.

Supplement Rauvolfia Vomitoria
Steady interest

#933 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Morphine Sulfate
Steady interest

#1,606 of 2,830 medications looked up here in the last 7 days

29 days ago today

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.

Supplement

About Rauvolfia Vomitoria

What is Rauvolfia Vomitoria?

  • High blood pressure
  • Anxiety and agitation
  • Sleep problems
  • Mental health symptoms (traditional use)
  • Fever and general ailments

Rauvolfia vomitoria is an African shrub whose root contains powerful alkaloids, including reserpine, that have historically been used for high blood pressure and agitation. Because these compounds can strongly affect blood pressure, mood, and the nervous system, the plant can cause serious side effects and is not a casual supplement. Always talk to a doctor or pharmacist before using it.

Read the full Rauvolfia Vomitoria monograph & all interactions
Medication

About Morphine

What Is Morphine Used For?

Brand names: MS Contin, Kadian, Avinza, Morphabond, Arymo ER

Morphine is used to manage acute (short-term) and chronic (long-term) pain that is severe enough to need an opioid and that hasn't been adequately treated by other options. The higher-concentration liquid form is reserved for adults who are already opioid-tolerant — meaning their body is used to opioid medications.

Because of real risks of addiction, misuse, and overdose, morphine is only prescribed when other pain treatments have not worked or are not expected to work. It is not intended for long-term use unless the pain continues to be severe and no alternatives are suitable.

See full Morphine drug information
Keep checking

Other Drugs & Rauvolfia Vomitoria

Browse every other medication we’ve checked against Rauvolfia Vomitoria — both the ones with a known interaction and the ones without. Select any drug for the full detail.

230Major
522Moderate
87Minor
1,990No known interaction
230 Major 522 Moderate 87 Minor 1,990 No interaction
Major

230 interactions

Showing 60 of 230 major interactions — see all 230 on the Rauvolfia Vomitoria page.

Moderate

522 interactions

Showing 60 of 522 moderate interactions — see all 522 on the Rauvolfia Vomitoria page.

Minor

87 interactions

Showing 60 of 87 minor interactions — see all 87 on the Rauvolfia Vomitoria page.

No interaction 1,990 drugs checked — show the list

We also checked Rauvolfia Vomitoria against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,990 medications checked with no known interaction — see the full Rauvolfia Vomitoria list.

See the full Rauvolfia Vomitoria interactions page
See every supplement checked against Morphine Sulfate, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

Keep exploring
Rauvolfia Vomitoria monograph › Uses, safety, and every drug interaction in one place Morphine Sulfate supplement interactions › Every supplement checked against Morphine Sulfate, ranked by severity Morphine drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Rauvolfia Vomitoria and Morphine Sulfate Together: Common Questions

Can you take Rauvolfia Vomitoria with Morphine Sulfate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Rauvolfia Vomitoria and Morphine Sulfate?
Morphine Sulfate belongs to more than one drug category, and Rauvolfia Vomitoria interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Rauvolfia Vomitoria and Morphine Sulfate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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.