Drug & supplement interaction

St. John's Wort + Tocainide

Tocainide brand name: Tonocard.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between St. John's Wort and Tocainide in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

St. John's Wort and Tocainide

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Tocainide and St. John's Wort in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

St. John's Wort safety at a glance

St. John's Wort overall Use caution Generally well tolerated short-term but has many serious drug interactions and can cause sun sensitivity.

Pregnancy Possibly Unsafe When used orally. Preliminary population research has found that taking St. John's wort while pregnant is associated with offspring that develop neural tube, ur... Read the full pregnancy detail

Breastfeeding Possibly Unsafe When used orally. Nursing infants of mothers who take St. John's wort have a greater chance of experiencing colic, drowsiness, and lethargy; avoid using. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Tocainide and St. John's Wort? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Tocainide

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tocainide is filed under a single classification — oral drugs. St. John's Wort has documented interactions with 47 drug classes — the most serious being alprazolam (xanax) (major), contraceptive drugs (major) and cyclosporine (neoral, sandimmune) (major) — and none of Tocainide’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

St. John's Wort Does Interact With Other Medications

St. John's Wort has 755 major, 388 moderate known drug interactions in our database — Tocainide isn’t one of them. If you take anything else, check it against the full list below.

Major 755 Moderate 388 No known interaction 1,687 (incl. Tocainide)

Taking anything else?

Check Another of Your Medications Against St. John's Wort

Covers the 2,830 medications we’ve checked against St. John's Wort. Pick one to open its full report.

What to actually watch for

What St. John's Wort Itself Has Been Linked To

This is not an interaction — nothing below involves Tocainide. It is the side-effect record for St. John's Wort on its own, from the licensed Natural Medicines monograph. If something new turns up after you add St. John's Wort, this list is the first place to look. 7 entries are worth acting on rather than waiting out — marked below.

Mania or an unusually elevated mood / Dependence or withdrawal symptoms / Serotonin syndrome / Confusion Worth acting on Additional detail
“St. John's wort can induce hypomania in depressed patients and mania in depressed patients with occult bipolar disorder. Cases of first-episode psychosis have been reported for females who used St. John's wort orally. In both cases, symptoms resolved following discontinuation of St. John's wort and treatment with antipsychotics for several weeks.”

St. John's Wort · Natural Medicines adverse-effect record, reported in anorexia.
6 sources cited

325. O'Breasail AM, Argouarch S. Hypomania and St John's wort. Can J Psychiatry 1998;43:746-7.

3524. Schneck C. St. John's wort and hypomania. J Clin Psychiatry 1998;59:689. PubMed

3555. Nierenberg AA, Burt T, Matthews J, et al. Mania associated with St. John's wort. Biol Psychiatry 1999;46:1707-8. PubMed

3568. Moses EL, Mallinger AG. St. John's wort: Three cases of possible mania induction. J Clin Psychopharmacol 2000;20:115-7. PubMed

10845. Hammerness P, Basch E, Ulbricht C, et al. St. John's wort: a systematic review of adverse effects and drug interactions for the consultation psychiatrist. Psychosomatics 2003;44:271-82. PubMed

76047. Barbenel, D. M., Yusufi, B., O'Shea, D., and Bench, C. J. Mania in a patient receiving testosterone replacement postorchidectomy taking St John's wort and sertraline. J Psychopharmacol 2000;14(1):84-86.
Thoughts of self-harm Worth acting on Additional detail

“Orally, St. John's wort is generally well tolerated.

Most Common Adverse Effects:

Orally: Diarrhea, dizziness, dry mouth, gastrointestinal discomfort (mild), fatigue, headache, insomnia, restlessness, and sedation.

Topically: Skin rash and photodermatitis.

Serious Adverse Effects (Rare):

Orally: There have been rare case reports of suicidal ideation and psychosis after taking St. John's wort.”

St. John's Wort · Natural Medicines adverse-effect record, reported in cluster headache.
Hallucinations Worth acting on Additional detail

Recorded for St. John's Wort in the same Natural Medicines adverse-effect record shown under Thoughts of self-harm above.
Yellowing of the skin or eyes Worth acting on Additional detail
“A case of acute hepatitis with prolonged cholestasis and features of vanishing bile duct syndrome has been reported for a patient who used tibolone and St. John's wort orally for 10 weeks. A case of jaundice with transaminitis and hyperbilirubinemia has been reported for a 79 year-old female who used St. John's wort and copaiba. Laboratory values normalized 7 weeks after discontinuation of both products.”

St. John's Wort · Natural Medicines adverse-effect record, reported in cholestasis.
2 sources cited

76135. Etogo-Asse, F., Boemer, F., Sempoux, C., and Geubel, A. Acute hepatitis with prolonged cholestasis and disappearance of interlobular bile ducts following tibolone and Hypericum perforatum (St. John's wort). Case of drug interaction? Acta Gastroenterol.Be

95505. Agollo MC, Miszputen SJ, Diament J. Hypericum perforatum-induced hepatotoxicity with possible association with copaiba (copaifera langsdorffii desf): a case report. Einstein (Sao Paulo) 2014;12(3):355-7.
Low mood Worth acting on Additional detail
“A case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in a 67-year-old male with depression has been reported. During a 3-month period, the patient was taking St. John's wort 300 mg daily then increased to 600-900 mg daily with no adverse effects despite a low serum sodium level of 122mEq/L, elevated levels of urine sodium, and urine osmolality suggestive of SIADH. St.”

St. John's Wort · Natural Medicines adverse-effect record, reported in depression.
1 source cited

95508. Jones D. Tourian LT, Margolese H. Possible association of syndrome of Inappropriate secretion of antidiuretic hormone with St. John's wort use. J of Clin Psychopharmacol 2014:34(6):759-60. PubMed
Kidney problems Worth acting on Additional detail
“Orally, St. John's wort has been associated with a case report of acute kidney failure in a 46-year-old female after one dose of homemade St. John's wort tea. Three sessions of hemodialysis were required before there was full recovery. However, causality is unclear since the patient had also been taking diclofenac intermittently for a month prior to developing kidney failure.”

St. John's Wort · Natural Medicines adverse-effect record, reported in kidney failure.
1 source cited

106741. Adibelli Z, Karacay I, Demir M, Duran C. St. John's Wort (Hypericum perforatum)-related acute kidney injury. Blood Purif. 2021 Aug 24:1-3. doi: 10.1159/000518349.
Raised blood pressure Worth acting on Additional detail
“In clinical research, palpitations have been reported for patients taking St. John's wort orally, although the number of these events was higher for the patients taking sertraline. In one case report, an adult female developed recurrent palpitations and supraventricular tachycardia (SVT) within 3 weeks of initiating St. John's wort 300 mg daily.”

St. John's Wort · Natural Medicines adverse-effect record, reported in hypertension.
6 sources cited

76070. van Gurp, G., Meterissian, G. B., Haiek, L. N., McCusker, J., and Bellavance, F. St John's wort or sertraline? Randomized controlled trial in primary care. Can Fam Physician 2002;48:905-912.

106051. Fisher KA, Patel P, Abualula S, Concepion L. St. John's Wort-Induced Supraventricular Tachycardia. Cureus. 2021 Apr 7;13(4):e14356. PubMed

10843. Hypericum Depression Trial Study Group. Effect of Hypericum perforatum (St. John's wort) in major depressive disorder: a randomized controlled trial. JAMA 2002;287:1807-14. PubMed

8931. Irefin S, Sprung J. A possible cause of cardiovascular collapse during anesthesia: long-term use of St. John's Wort. J Clin Anesth 2000;12:498-9. PubMed

76073. Zullino, D. and Borgeat, F. Hypertension induced by St. John's Wort - a case report. Pharmacopsychiatry 2003;36(1):32. PubMed

76128. Cappuzzo, K. A. Herbal product use in a patient with polypharmacy. Consult Pharm. 2006;21(11):911-915. PubMed

Showing the 10 most notable of 45 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for St. John's Wort — expand a row for the licensed statement it rests on. We haven’t matched Tocainide to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Tocainide.

Special populations

St. John's Wort in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally. Preliminary population research has found that taking St. John's wort while pregnant is associated with offspring that develop neural tube, urinary, and cardiovascular malformations. Subgroup analyses suggest that these risks may be higher when taking St. John's wort during the first trimester when compared with the second or third trimester. However, more research is needed to confirm these findings. Animal-model research also shows that constituents of St. John's wort might have teratogenic effects. Until more is known, St. John's wort should not be taken during pregnancy.

Lactation Possibly Unsafe

When used orally. Nursing infants of mothers who take St. John's wort have a greater chance of experiencing colic, drowsiness, and lethargy; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About St. John's Wort or Tocainide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers St. John's Wort or Tocainide, 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 Tocainide

This page covers St. John's Wort only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tocainide page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Tocainide page

“Tocainide (Tonocard) controls dangerous heart rhythm disturbances, so its blood level needs to stay where your cardiologist set it, and every one of the 17 ingredients on this page can move that level by changing how much drug your gut absorbs. Approach these combinations with real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Tocainide interaction page

One more smart check

Taking St. John's Wort as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,159 real supplement products containing St. John's Wort, each one broken down to its full ingredient list — and combination products often carry several ingredients besides St. John's Wort. Even though St. John's Wort itself has no known interaction with Tocainide, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where St. John's Wort and Tocainide 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 St. John's Wort

Top 25%

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

29 days ago today

Medication Tocainide

Top 5%

#76 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.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every St. John's Wort reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The St. John's Wort and Tocainide records this page draws on were last updated July 11, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Supplement

About St. John's Wort

What is St. John's Wort?

Mild to moderate depression
Anxiety and stress
Sleep problems
Menopausal symptoms
Wound healing (topical)

St. John's wort is a well-studied herb most often used for mild to moderate depression, and some research suggests it may help with this. However, it has many serious interactions with prescription medicines and is not safe for everyone, so always talk to your pharmacist or doctor before taking it.

Hypericum perforatum · Hypericaceae · Flowering tops and aerial parts (leaves and flowers) · Capsules, tablets, standardized extracts, teas, tinctures, and topical oils

An interaction check asks whether these two react with each other — it does not ask whether St. John's Wort is a good idea for someone in your situation. Here is what our St. John's Wort record says about it on its own.

St. John's Wort: dosing

There is no single official dose for St. John's wort. Products vary widely in strength, and many studies use extracts standardized to a set amount of hypericin or hyperforin. Because of this, the right dose depends on the specific product.The safest approach is to follow the directions on the product label and to choose a standardized extract from a reputable brand. Effects on mood, if any, may take several weeks to appear.

From our St. John's Wort monograph — the full record covers uses, side effects and every documented interaction.

Read the full St. John's Wort monograph & all interactions

Keep checking

Other Drugs & St. John's Wort

Browse every other medication we’ve checked against St. John's Wort — both the ones with a known interaction and the ones without. Select any drug for the full detail.

755Major

388Moderate

0Minor

1,686No known interaction

755 Major 388 Moderate 1,686 No interaction

Major

755 interactions

Showing 60 of 755 major interactions — see all 755 on the St. John's Wort page.

Moderate

388 interactions

Showing 60 of 388 moderate interactions — see all 388 on the St. John's Wort page.

No interaction 1,686 drugs checked — show the list

We also checked St. John's Wort against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,686 medications checked with no known interaction — see the full St. John's Wort list.

See the full St. John's Wort interactions page

See every supplement checked against Tocainide, ranked by severity

Evidence & sources

St. John's Wort References

The 152 references that drive our St. John's Wort monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Miller LG. Herbal Medicinals: Selected clinical considerations focusing on known or potential drug-herb interactions. Arch Intern Med 1998;158:2200-11.
Gulick RM, McAuliffe V, Holden-Wiltse J, et al. Phase I studies of hypericin, the active compound in St. John's Wort, as an antiretroviral agent in HIV-infected adults. AIDS Clinical Trials Group Protocols 150 and 258. Ann Intern Med 1999;130:510-4. PubMed
O'Breasail AM, Argouarch S. Hypomania and St John's wort. Can J Psychiatry 1998;43:746-7.
Johne A, Brockmoller J, Bauer S, et al. Pharmacokinetic interaction of digoxin with an herbal extract from St John's wort (Hypericum perforatum). Clin Pharmacol Ther 1999;66:338-45.
Gordon JB. SSRIs and St. John's Wort: possible toxicity? Am Fam Physician 1998;57:950, 953.
Golsch S, Vocks E, Rakoski J, et al. [Reversible increase in photosensitivity to UV-B caused by St. John's wort extract]. Hautarzt 1997;48:249-52.
Bove GM. Acute neuropathy after exposure to sun in a patient treated with St. John's Wort. Lancet 1998;352:1121-2. PubMed
Brockmoller J, Reum T, Bauer S, et al. Hypericin and pseudohypericin: pharmacokinetics and effects on photosensitivity in humans. Pharmacopsychiatry 1997;30:94-101. PubMed
Upton R, ed. St. John's wort, Hypericum perforatum: Quality control, analytical and therapeutic monograph. Santa Cruz, CA: American Herbal Pharmacopoeia 1997;1-32.
Muller WE, Singer A, Wonnemann M, et al. Hyperforin represents the neurotransmitter reuptake inhibiting constituent of hypericum extract. Pharmacopsychiatry 1998;31:16-21.
Abul-Ezz SR, Barone GW, Gurley BJ, et al. Effect of herbal supplements on cyclosporine blood levels and associated acute rejection. Am Soc of Nephrol Ann Mtg, Toronto, CAN 2000;Oct. 11-16:abstract A3754.
Piscitelli SC, Burstein AH, Chaitt D, et al. Indinavir concentrations and St John's wort. Lancet 2000;355:547-8. PubMed
Yue QY, Bergquist C, Gerden B. Safety of St. John's wort (Hypericum perforatum). Lancet 2000;355:576-7. PubMed
Ruschitzka F, Meier PJ, Turina M, et al. Acute heart transplant rejection due to Saint John's wort. Lancet 2000;355:548-9. PubMed
Roberts JE, Wang RH, Tan IP, et al. Hypericin (active ingredient in St. John's wort) photo-oxidation of lens proteins. Photochem Photobiol 1999;69:42S.
Gurley BJ, Barone GW. Herb-drug interaction involving St. John's wort and cyclosporine. AAPS Ann Mtg & Expo Indianapolis, IN:2000;Oct 29- Nov 2: presentation #3443.
Durr D, Stieger B, Kullak-Ublick GA, et al. St. John's Wort induces intestinal P-glycoprotein/MDR1 and intestinal and hepatic CYP3A4. Clin Pharmacol Ther 2000;68:598-604. PubMed
Lee A, Minhas R, Ito S, et al. Safety of St. John's wort during breastfeeding. Clin Pharmacol Ther 2000;67:130, abstract PII-64.
Schneck C. St. John's wort and hypomania. J Clin Psychiatry 1998;59:689. PubMed
Nierenberg AA, Burt T, Matthews J, et al. Mania associated with St. John's wort. Biol Psychiatry 1999;46:1707-8. PubMed
Nebel A, Schneider BJ, Baker RA, et al. Potential metabolic interaction between St. John's wort and theophylline. Ann Pharmacother 1999;33:502. PubMed
Moses EL, Mallinger AG. St. John's wort: Three cases of possible mania induction. J Clin Psychopharmacol 2000;20:115-7. PubMed
Beckman SE, Sommi RW, Switzer J. Consumer use of St. John's wort: A survey of effectiveness, safety, and tolerability. Pharmacotherapy 2000;20:568-74.
Peirce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York, NY: William Morrow and Co., 1999.
Mai I, Kruger H, Budde K, et al. Hazardous pharmacokinetic interaction of Saint John's wort (Hypericum perforatum) with the immunosuppressant cyclosporin. Int J Clin Pharmacol Ther 2000;38:500-2. PubMed
Schempp CM, Muller K, Winghofer B, et al. Single-dose and steady-state administration of Hypericum perfotatum extract (St. John's wort) does not influence skin sensitivity to UV radiation, visible light, and solar-stimulated radiation. Arch Dermatol 2001;
Schempp CM, Ludtke R, Winghofer B, Simon JC. Effect of topical application of hypericum perforatum extract on skin sensitivity to solar simulated radiation. Photodermatol Photoimmunol Photomed 2000;16:125-8.
Jacobson JM, Feinman L, Liebes L, et al. Pharmacokinetics, safety, and antiviral effects of hypericin, a derivative of St. John's Wort plant, in patients with chronic hepatitis C virus infection. Antimicrob Agents Chemother 2001;45:517-24. PubMed
Moschella C, Jaber BL. Interaction between cyclosporine and Hypericum perforatum (St. John's wort) after organ transplantation. Amer J Kidney Dis 2001;38:1105-7. PubMed
Karliova M, Treichel U, Malago M, et al. Interaction of Hypericum perforatum (SJW) with cyclosporin A metabolism in a patient after liver transplantation. J Hepatol 2000;33:853-5.
Mandelbaum A, Pertzborn F, Martin-Facklam M, Wiesel M. Unexplained decrease of cyclosporin trough levels in a compliant renal transplant patient. Nephrol Dial Transplant 2000;15:1473-4. PubMed
Assalian P. Sildenafil for SJW-induced sexual dysfunction. J Sex Marital Ther 2000;26:357-8.
de Maat M, Hoetelmans R, Mathot R, et al. Drug interaction between St. John's wort and nevirapine. AIDS 2001;15:420-1. PubMed
Schrader E. Equivalence of St. John's wort extract (Ze 117) and fluoxetine: a randomized, controlled study in mild-moderate depression. Int Clin Psychopharmacol 2000;15:61-8.
Ernst E, Rand JI, Barnes J, Stevinson C. Adverse effects profile of the herbal antidepressant St. John's wort (Hypericum perforatum L.). Eur J Clin Pharmacol 1998;54:589-94. PubMed
Shelton RC, Keller MB, Gelenberg A, et al. Effectiveness of St. John's wort in major depression: A randomized, placebo-controlled trial. JAMA 2001;285:1978-86. DOI
Breidenbach T, Hoffmann MW, Becker T, et al. Drug interaction of St. John's wort with cyclosporin. Lancet 2000;355:1912.
Brown TM. Acute St. John's wort toxicity. Am J Emerg Med 2000;18:231-2. PubMed
Kleber E, Obry T, Hippeli S, et al. Biochemical activities of extracts from Hypericum perforatum L. 1st Communication: inhibition of dopamine-beta-hydroxylase. Arzneimittelforschung 1999;49:106-9.
Barone GW, Gurley BJ, Ketel BL, et al. Drug interaction between St. John's wort and cyclosporin. Ann Pharmacother 2000;34:1013-6.
Cheng TO. St. John's wort interaction with digoxin [letter]. Arch Intern Med 2000;160:2548. PubMed
Lane-Brown MM. Photosensitivity associated with herbal preparations of St. John's wort (Hypericum perforatum). Med J Aust 2000;172:302.
Mathijssen RHJ, Verweij J, De Bruijn P, et al. Modulation of irinotecan (CPT-11) metabolism by St. John's wort in cancer patients. American Association for Cancer Research Annual Meeting, San Francisco, April 2002. Abstract 2443.
Mai I, Bauer S, Krueger H, et al. Wechselwirkungen von Johaniskraut mit tacrolismus bei nierentransplantierten patienten. Symposium Phytopharmaka VII. Forschung und Klinische Anwendung, Berlin, October, 2001.
Bhopal JS. St John's wort-induced sexual dysfunction. Can J Psychiatry 2001;46:456-457. PubMed
Schulz V. Incidence and clinical relevance of the interactions and side effects of Hypericum preparations. Phytomedicine 2001;8:152-60.
Gorski JC, Hamman MA, Wang Z, et al. The effect of St. John's wort on the efficacy of oral contraceptives (abstract MPI-80). Clin Pharmacol Ther 2001;71:P25.
Hennessy M, Kelleher D, Spiers JP, et al. St Johns wort increases expression of P-glycoprotein: implications for drug interactions. Br J Clin Pharmacol 2002;53:75-82.
Parker V, Wong AH, Boon HS, Seeman MV. Adverse reactions to St John's Wort. Can J Psychiatry 2001;46:77-9. PubMed
Patel S, Robinson R, Burk M. Hypertensive crisis associated with St. John's Wort. Am J Med 2002;112:507-8. PubMed
Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
Holme SA, Roberts DL. Erythroderma associated with St John's wort. Br J Dermatol 2000;143:1127-8. PubMed
Irefin S, Sprung J. A possible cause of cardiovascular collapse during anesthesia: long-term use of St. John's Wort. J Clin Anesth 2000;12:498-9. PubMed
Calapai G, Crupi A, Firenzuoli F, et al. Serotonin, norepinephrine and dopamine involvement in the antidepressant action of hypericum perforatum. Pharmacopsychiatry 2001;34:45-9. PubMed
Henderson L, Yue QY, Bergquist C, et al. St John's wort (Hypericum perforatum): drug interactions and clinical outcomes. Br J Clin Pharmacol 2002;54:349-56..
Mathijssen RH, Verweij J, de Bruijn P, et al. Effects of St. John's wort on irinotecan metabolism. J Natl Cancer Inst 2002;94:1247-9.. PubMed
Ladner DP, Klein SD, Steiner RA, Walt H. Synergistic toxicity of delta-aminolaevulinic acid-induced protoporphyrin IX used for photodiagnosis and hypericum extract, a herbal antidepressant. Br J Dermatol 2001;144:916-8. PubMed
Ernst E. St. John's Wort supplements endanger the success of organ transplantation. Arch Surg 2002;137:316-9. PubMed
Wang Z, Hamman MA, Huang SM, et al. Effect of St. John's wort on the pharmacokinetics of fexofenadine. Clin Pharmacol Ther 2002;71:414-20.. PubMed
Chan LY, Chiu PY, Lau TK. A study of hypericin-induced teratogenicity during organogenesis using a whole rat embryo culture model. Fertil Steril 2001;76:1073-4. PubMed
Schwarz UI, Buschel B, Kirch W. Unwanted pregnancy on self-medication with St John's wort despite hormonal contraception. Br J Clin Pharmacol 2003;55:112-3. PubMed
Logan JL, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjogren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol 2003;22:158-9.
Mai I, Stormer E, Bauer S, et al. Impact of St John's wort treatment on the pharmacokinetics of tacrolimus and mycophenolic acid in renal transplant patients. Nephrol Dial Transplant 2003;18:819-22.. PubMed
Groning R, Breitkreutz J, Muller RS. Physico-chemical interactions between extracts of Hypericum perforatum L. and drugs. Eur J Pharm Biopharm 2003;56:231-6.. PubMed
Sugimoto K, Ohmori M, Tsuruoka S, et al. Different effects of St John's wort on the pharmacokinetics of simvastatin and pravastatin. Clin Pharmacol Ther 2001;70:518-24.. DOI
Bauer S, Stormer E, Johne A, et al. Alterations in cyclosporin A pharmacokinetics and metabolism during treatment with St John's wort in renal transplant patients. Br J Clin Pharmacol 2003;55:203-11.. PubMed
Markowitz JS, Donovan JL, DeVane CL, et al. Effect of St. John's wort on drug metabolism by induction of cytochrome P450 3A4 enzyme. JAMA 2003;290:1500-4.. PubMed
Hypericum Depression Trial Study Group. Effect of Hypericum perforatum (St. John's wort) in major depressive disorder: a randomized controlled trial. JAMA 2002;287:1807-14. PubMed
Hammerness P, Basch E, Ulbricht C, et al. St. John's wort: a systematic review of adverse effects and drug interactions for the consultation psychiatrist. Psychosomatics 2003;44:271-82. PubMed
Gurley BJ, Gardner SF, Hubbard MA, et al. Cytochrome P450 phenotypic ratios for predicting herb-drug interactions in humans. Clin Pharmacol Ther 2002;72:276-87.. PubMed
Foster BC, Vandenhoek S, Hana J, et al. In vitro inhibition of human cytochrome P450-mediated metabolism of marker substrates by natural products. Phytomedicine 2003;10:334-42.. PubMed
Kim RB. Drugs as P-glycoprotein substrates, inhibitors, and inducers. Drug Metab Rev 2002;34:47-54. PubMed
Dean AJ, Moses GM, Vernon JM. Suspected withdrawal syndrome after cessation of St. John's wort. Ann Pharmacother 2003;37:150. PubMed
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Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking St. John's Wort and Tocainide Together: Common Questions

Is it safe to take St. John's Wort with Tocainide?

We do not list a known interaction between St. John's Wort and Tocainide. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

How was the St. John's Wort and Tocainide combination checked?

Interactions in our licensed database are recorded against drug classes. Tocainide is filed under 1 classification, and St. John's Wort has documented interactions with 47 drug classes — none of Tocainide's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does St. John's Wort interact with any other medications?

Yes. St. John's Wort has 1,143 documented drug interactions in our database — Tocainide is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Tocainide interact with any supplements?

Yes. Tocainide has documented interactions with 17 supplements in our database — St. John's Wort is not one of them. The Tocainide interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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