Drug & supplement interaction

Fever Bark + Efgartigimod alfa-fcab

Efgartigimod alfa-fcab brand name: Vyvgart.

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 Fever Bark and Efgartigimod alfa-fcab 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.

Know someone taking this? Share

Facebook Post Reddit Email

On this page

Interaction report

Fever Bark and Efgartigimod alfa-fcab

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 Efgartigimod alfa-fcab and Fever Bark 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.

Fever Bark safety at a glance

Fever Bark overall Use caution The bark contains strong alkaloids and is not recommended without professional supervision.

Pregnancy Avoid Not enough safety data and potent alkaloids make it unsafe to use during pregnancy.

Breastfeeding Avoid No reliable safety information exists, so avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Efgartigimod alfa-fcab and Fever Bark? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Efgartigimod alfa-fcab

Interactions in our licensed database are recorded against drug classes, not just single drug names. Efgartigimod alfa-fcab is filed under a single classification — immunosuppressants. Fever Bark has documented interactions with 9 drug classes — the most serious being anesthesia (major), monoamine oxidase inhibitors (maois) (major) and antihypertensive drugs (moderate) — and none of Efgartigimod alfa-fcab’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

Fever Bark Does Interact With Other Medications

Fever Bark has 40 major, 674 moderate, 87 minor known drug interactions in our database — Efgartigimod alfa-fcab isn’t one of them. If you take anything else, check it against the full list below.

Major 40 Moderate 674 Minor 87 No known interaction 2,029 (incl. Efgartigimod alfa-fcab)

Taking anything else?

Check Another of Your Medications Against Fever Bark

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

What to actually watch for

What Fever Bark Itself Has Been Linked To

This is not an interaction — nothing below involves Efgartigimod alfa-fcab. It is the side-effect record for Fever Bark on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Fever Bark, this list is the first place to look. 5 entries are worth acting on rather than waiting out — marked below.

Heart failure / Raised blood pressure Worth acting on Additional detail
“The yohimbine constituent of fever bark, when taken alone in high doses, can cause hypertension, cardiac conduction abnormalities, and cardiac failure, It is not known if these effects occur with fever bark.”

Fever Bark · Natural Medicines adverse-effect record, reported in hypertension.
4 sources cited

17465. Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother 2010;44:1022-9. PubMed

86856. Brodde, O. E., Anlauf, M., Arroyo, J., Wagner, R., Weber, F., and Buck, K. D. Hypersensitivity of adrenergic receptors and blood-pressure response to oral yohimbine in orthostatic hypotension. N.Engl.J Med 4-28-1983;308(17):1033-1034. PubMed

86786. Adeniyi, A. A., Brindley, G. S., Pryor, J. P., and Ralph, D. J. Yohimbine in the treatment of orgasmic dysfunction. Asian J Androl 2007;9(3):403-407. PubMed

86896. Riley AJ, Goodman R, Kellett JM, and et al. Double blind trial of yohimbine hydrochloride in the treatment of erection inadequacy. Sexual Marital Ther 1989;4(1):17-26. DOI
Wheezing Worth acting on Additional detail
“The yohimbine constituent of fever bark, when taken alone, may cause bronchospasm, tachynpea, cough, and rhinorrhea. The reserpine constituent of fever bark, when taken alone, may cause nasal congestion or bronchospasm (15,94328). It is not known if this occurs with fever bark.”

Fever Bark · Natural Medicines adverse-effect record, reported in cough.
5 sources cited

17465. Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother 2010;44:1022-9. PubMed

86825. Landis, E. and Shore, E. Yohimbine-induced bronchospasm. Chest 1989;96(6):1424. PubMed

86850. Charney, D. S., Heninger, G. R., and Sternberg, D. E. Assessment of alpha 2 adrenergic autoreceptor function in humans: effects of oral yohimbine. Life Sci 6-7-1982;30(23):2033-2041.

15. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.

94328. Lobay D. Rauwolfia in the Treatment of Hypertension. Integr Med (Encinitas). 2015 Jun;14(3):40-6.
Seizures Worth acting on Additional detail
“The yohimbine constituent of fever bark, when taken alone in high doses, causes general central nervous system and autonomic excitation, tremulousness, head twitching, seizure threshold changes, dizziness, vertigo, and headache. It is not known if this occurs with fever bark.”

Fever Bark · Natural Medicines adverse-effect record, reported in cluster headache.
6 sources cited

3312. Teloken C, Rhoden EL, Sogari P, et al. Therapeutic effects of high dose yohimbine hydrochloride on organic erectile dysfunction. J Urol 1998;159:122-4. PubMed

3971. Hollander E, McCarley A. Yohimbine treatment of sexual side effects induced by serotonin reuptake blockers. J Clin Psychiatry 1992;53:207-9.

86774. Cameron, O. G., Zubieta, J. K., Grunhaus, L., and Minoshima, S. Effects of yohimbine on cerebral blood flow, symptoms, and physiological functions in humans. Psychosom.Med 2000;62(4):549-559. PubMed

86779. Bowes, M. P., Peters, R. H., Kernan, W. J., Jr., and Hopper, D. L. Effects of yohimbine and idazoxan on motor behaviors in male rats. Pharmacol.Biochem.Behav. 1992;41(4):707-713.

86786. Adeniyi, A. A., Brindley, G. S., Pryor, J. P., and Ralph, D. J. Yohimbine in the treatment of orgasmic dysfunction. Asian J Androl 2007;9(3):403-407. PubMed

86804. Myers, A. and Barrueto, F., Jr. Refractory priapism associated with ingestion of yohimbe extract. J Med Toxicol. 2009;5(4):223-225.
Low mood Worth acting on Additional detail
“The yohimbine constituent of fever bark, when taken alone, causes malaise, fatigue, irritability insomnia, restlessness, agitation, and anxiety. The reserpine constituent of fever bark, when taken alone, causes depression (17). It is not known if these effects occur with fever bark.”

Fever Bark · Natural Medicines adverse-effect record, reported in anxiety.
6 sources cited

3312. Teloken C, Rhoden EL, Sogari P, et al. Therapeutic effects of high dose yohimbine hydrochloride on organic erectile dysfunction. J Urol 1998;159:122-4. PubMed

3970. Jacobsen FM. Fluoxetine-induced sexual dysfunction and an open trial of yohimbine. J Clin Psychiatry 1992;53:119-22.

3971. Hollander E, McCarley A. Yohimbine treatment of sexual side effects induced by serotonin reuptake blockers. J Clin Psychiatry 1992;53:207-9.

17465. Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother 2010;44:1022-9. PubMed

86786. Adeniyi, A. A., Brindley, G. S., Pryor, J. P., and Ralph, D. J. Yohimbine in the treatment of orgasmic dysfunction. Asian J Androl 2007;9(3):403-407. PubMed

86801. Giampreti, A., Lonati, D., Locatelli, C., Rocchi, L., and Campailla, M. T. Acute neurotoxicity after yohimbine ingestion by a body builder. Clin Toxicol.(Phila) 2009;47(8):827-829. PubMed
An allergic reaction Worth acting on Additional detail
“The yohimbine constituent of fever bark, when taken alone, causes allergic reactions (2,5,6,11,18). It is not known if this occurs with fever bark.”

Fever Bark · Natural Medicines adverse-effect record, reported in fever.
5 sources cited

2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.

5. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.

6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

11. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.

18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Mood changes or irritability / Anxiety or restlessness Additional detail

Recorded for Fever Bark in the same Natural Medicines adverse-effect record shown under Low mood above.
A stuffy or runny nose / Cough Additional detail

Recorded for Fever Bark in the same Natural Medicines adverse-effect record shown under Wheezing above.

Showing the 10 most notable of 18 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 Fever Bark — expand a row for the licensed statement it rests on. We haven’t matched Efgartigimod alfa-fcab 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 Efgartigimod alfa-fcab.

Everything else you take

See Every Supplement That Interacts With Efgartigimod alfa-fcab

This page covers Fever Bark only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Efgartigimod alfa-fcab page lists 53 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Active Hexose Correlated Compound (ahcc) (moderate), Alfalfa (moderate), American Ginseng (moderate), Andrographis (moderate) and Ashwagandha (moderate).

By severity: 52 moderate · 1 minor.

From our pharmacist’s overview on the Efgartigimod alfa-fcab page

“Every supplement on this list points the same direction for someone taking efgartigimod alfa-fcab (Vyvgart). The drug works by dialing down part of the immune system to treat generalized myasthenia gravis, and each of these ingredients, echinacea, astragalus, and American ginseng among them, is thought to stimulate immunity, which coul…”

Reviewed by 2 · Jul 18, 2026

Open the Efgartigimod alfa-fcab interaction page

How much people look this up

Where Fever Bark and Efgartigimod alfa-fcab 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 Fever Bark

Steady interest

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

29 days ago today

Medication Efgartigimod alfa-fcab

Top half

#1,178 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 Fever Bark reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Fever Bark and Efgartigimod alfa-fcab records this page draws on were last updated July 10, 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 Fever Bark

What is Fever Bark?

Fever
Diarrhea
Malaria (traditional)
Digestive complaints
Bitter tonic

Fever bark is the bark of the Australian tree Alstonia constricta, used in traditional medicine for fever, diarrhea, and infections. There is very little reliable human research to support these uses, and the bark contains potent alkaloids that may cause serious side effects. It is best avoided unless used under direct medical supervision.

Alstonia constricta · Apocynaceae · Bark · Bark powder, tincture, liquid extract, capsules

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

Fever Bark: dosing

There is no well-established, standardized dose for fever bark. Because the bark contains potent alkaloids that vary between products, a safe and effective dose has not been reliably determined in modern research.If a product is used at all, follow the directions on the label and do not exceed them.

From our Fever Bark monograph — the full record covers uses, side effects and every documented interaction.

Read the full Fever Bark monograph & all interactions

Medication

About Efgartigimod alfa-fcab Injection

What Is Efgartigimod alfa-fcab Injection Used For?

Brand name: Vyvgart

Efgartigimod alfa-fcab injection is used to treat a certain form of myasthenia gravis (MG; a disorder of the nervous system that causes muscle weakness). Efgartigimod alfa-fcab is in a group of medications called monoclonal antibodies. It works by reducing a certain natural substance in the body that causes symptoms of myasthenia gravis.

See full Efgartigimod alfa-fcab Injection drug information

Keep checking

Other Drugs & Fever Bark

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

40Major

674Moderate

87Minor

2,028No known interaction

40 Major 674 Moderate 87 Minor 2,028 No interaction

Major

40 interactions

Moderate

674 interactions

Showing 60 of 674 moderate interactions — see all 674 on the Fever Bark page.

Minor

87 interactions

Showing 60 of 87 minor interactions — see all 87 on the Fever Bark page.

No interaction 2,028 drugs checked — show the list

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

Showing the 60 most looked-up of 2,028 medications checked with no known interaction — see the full Fever Bark list.

See the full Fever Bark interactions page

See every supplement checked against Efgartigimod alfa-fcab, ranked by severity

Evidence & sources

Fever Bark References

The 50 references that drive our Fever Bark 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.

Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
Sklar S, et al. Drug therapy screening system. Indianapolis, IN: First Data Bank 99.1-99. 2 eds.
Teloken C, Rhoden EL, Sogari P, et al. Therapeutic effects of high dose yohimbine hydrochloride on organic erectile dysfunction. J Urol 1998;159:122-4. PubMed
Jacobsen FM. Fluoxetine-induced sexual dysfunction and an open trial of yohimbine. J Clin Psychiatry 1992;53:119-22.
Hollander E, McCarley A. Yohimbine treatment of sexual side effects induced by serotonin reuptake blockers. J Clin Psychiatry 1992;53:207-9.
Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother 2010;44:1022-9. PubMed
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
Abebe, W. An overview of herbal supplement utilization with particular emphasis on possible interactions with dental drugs and oral manifestations. J Dent.Hyg. 2003;77(1):37-46.
Mustonen, P., Savola, J., and Lassila, R. Atipamezole, an imidazoline-type alpha(2)-adrenoceptor inhibitor, binds to human platelets and inhibits their adrenaline-induced aggregation more effectively than yohimbine. Thromb.Res 8-1-2000;99(3):231-237.
Cameron, O. G., Zubieta, J. K., Grunhaus, L., and Minoshima, S. Effects of yohimbine on cerebral blood flow, symptoms, and physiological functions in humans. Psychosom.Med 2000;62(4):549-559. PubMed
Bowes, M. P., Peters, R. H., Kernan, W. J., Jr., and Hopper, D. L. Effects of yohimbine and idazoxan on motor behaviors in male rats. Pharmacol.Biochem.Behav. 1992;41(4):707-713.
Bagheri, H., Schmitt, L., Berlan, M., and Montastruc, J. L. Effect of 3 weeks treatment with yohimbine on salivary secretion in healthy volunteers and in depressed patients treated with tricyclic antidepressants. Br J Clin Pharmacol 1992;34(6):555-558. PubMed
Bagheri, H., Bompart, G., Girolami, J. P., Montastruc, J. L., and Montastruc, P. Is yohimbine-induced increase in salivary secretion a kinin-dependent mechanism? Fundam.Clin Pharmacol 1992;6(1):17-20. PubMed
Adeniyi, A. A., Brindley, G. S., Pryor, J. P., and Ralph, D. J. Yohimbine in the treatment of orgasmic dysfunction. Asian J Androl 2007;9(3):403-407. PubMed
Giampreti, A., Lonati, D., Locatelli, C., Rocchi, L., and Campailla, M. T. Acute neurotoxicity after yohimbine ingestion by a body builder. Clin Toxicol.(Phila) 2009;47(8):827-829. PubMed
Myers, A. and Barrueto, F., Jr. Refractory priapism associated with ingestion of yohimbe extract. J Med Toxicol. 2009;5(4):223-225.
Berlin, I., Crespo-Laumonnier, B., Cournot, A., Landault, C., Aubin, F., Legrand, J. C., and Puech, A. J. The alpha 2-adrenergic receptor antagonist yohimbine inhibits epinephrine-induced platelet aggregation in healthy subjects. Clin Pharmacol.Ther. 199
Cimolai, N. and Cimolai, T. Yohimbine use for physical enhancement and its potential toxicity. J Diet.Suppl 2011;8(4):346-354. PubMed
Bagheri, H., Berlan, M., Montastruc, J. L., and Montastruc, P. Yohimbine and lacrimal secretion. Br J Clin Pharmacol. 1990;30(1):151-152.
Landis, E. and Shore, E. Yohimbine-induced bronchospasm. Chest 1989;96(6):1424. PubMed
Susset, J. G., Tessier, C. D., Wincze, J., Bansal, S., Malhotra, C., and Schwacha, M. G. Effect of yohimbine hydrochloride on erectile impotence: a double-blind study. J Urol. 1989;141(6):1360-1363. PubMed
Chatelut, E., Rispail, Y., Berlan, M., and Montastruc, J. L. Yohimbine increases human salivary secretion. Br.J Clin Pharmacol. 1989;28(3):366-368. PubMed
Montastruc, P., Berlan, M., and Montastruc, J. L. Effects of yohimbine on submaxillary salivation in dogs. Br J Pharmacol 1989;98(1):101-104. PubMed
Charney, D. S., Price, L. H., and Heninger, G. R. Desipramine-yohimbine combination treatment of refractory depression. Implications for the beta-adrenergic receptor hypothesis of antidepressant action. Arch.Gen.Psychiatry 1986;43(12):1155-1161. PubMed
Braddock, L., Cowen, P. J., Elliott, J. M., Fraser, S., and Stump, K. Binding of yohimbine and imipramine to platelets in depressive illness. Psychol.Med 1986;16(4):765-773. PubMed
Charney, D. S., Heninger, G. R., and Sternberg, D. E. Assessment of alpha 2 adrenergic autoreceptor function in humans: effects of oral yohimbine. Life Sci 6-7-1982;30(23):2033-2041.
Boon, N. A., Elliott, J. M., Grahame-Smith, D. G., John-Green, T., and Stump, K. A comparison of alpha 2-adrenoreceptor binding characteristics of intact human platelets identified by [3H]-yohimbine and [3H]- dihydroergocryptine. J Auton.Pharmacol 1983;3
Brodde, O. E., Anlauf, M., Arroyo, J., Wagner, R., Weber, F., and Buck, K. D. Hypersensitivity of adrenergic receptors and blood-pressure response to oral yohimbine in orthostatic hypotension. N.Engl.J Med 4-28-1983;308(17):1033-1034. PubMed
Charney, D. S., Heninger, G. R., and Redmond, D. E., Jr. Yohimbine induced anxiety and increased noradrenergic function in humans: effects of diazepam and clonidine. Life Sci. 7-4-1983;33(1):19-29. PubMed
Knoll, L. D., Benson, R. C., Jr., Bilhartz, D. L., Minich, P. J., and Furlow, W. L. A randomized crossover study using yohimbine and isoxsuprine versus pentoxifylline in the management of vasculogenic impotence. J Urol. 1996;155(1):144-146. DOI
Bagheri, H., Chale, J. J., Guyen, L. N., Tran, M. A., Berlan, M., and Montastruc, J. L. Evidence for activation of both adrenergic and cholinergic nervous pathways by yohimbine, an alpha 2-adrenoceptor antagonist. Fundam.Clin Pharmacol 1995;9(3):248-254.
Morgan, C. A., III, Southwick, S. M., Grillon, C., Davis, M., Krystal, J. H., and Charney, D. S. Yohimbine-facilitated acoustic startle reflex in humans. Psychopharmacology (Berl) 1993;110(3):342-346. PubMed
Biaggioni, I., Robertson, R. M., and Robertson, D. Manipulation of norepinephrine metabolism with yohimbine in the treatment of autonomic failure. J Clin Pharmacol. 1994;34(5):418-423. PubMed
Mann, K., Klingler, T., Noe, S., Roschke, J., Muller, S., and Benkert, O. Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction. Arch.Sex Behav. 1996;25(1):1-16. PubMed
Rowland, D. L., Kallan, K., and Slob, A. K. Yohimbine, erectile capacity, and sexual response in men. Arch Sex Behav 1997;26(1):49-62.
Bremner, J. D., Innis, R. B., Ng, C. K., Staib, L. H., Salomon, R. M., Bronen, R. A., Duncan, J., Southwick, S. M., Krystal, J. H., Rich, D., Zubal, G., Dey, H., Soufer, R., and Charney, D. S. Positron emission tomography measurement of cerebral metaboli
Riley AJ, Goodman R, Kellett JM, and et al. Double blind trial of yohimbine hydrochloride in the treatment of erection inadequacy. Sexual Marital Ther 1989;4(1):17-26. DOI
Lobay D. Rauwolfia in the Treatment of Hypertension. Integr Med (Encinitas). 2015 Jun;14(3):40-6.
Sheldon MB, Kotte JH. Effect of Rauwolfia serpentina and reserpine on the blood pressure in essential hypertension; a long-term double-blind study. Circulation. 1957 Aug;16(2):200-6.
Le Corre P, Parmer RJ, Kailasam MT, et al. Human sympathetic activation by alpha2-adrenergic blockade with yohimbine: Bimodal, epistatic influence of cytochrome P450-mediated drug metabolism. Clin Pharmacol Ther. 2004;76(2):139-53.
Mueller-Schoell A, Michelet R, Weinelt F, Kloft C, Mikus G. CYP2D6 phenotype explains reported yohimbine concentrations in four severe acute intoxications. Arch Toxicol. 2021. PubMed
Bharucha AE, Skaar T, Andrews CN, et al Relationship of cytochrome P450 pharmacogenetics to the effects of yohimbine on gastrointestinal transit and catecholamines in healthy subjects. Neurogastroenterol Motil. 2008;20(8):891-9. PubMed

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 Fever Bark and Efgartigimod alfa-fcab Together: Common Questions

Is it safe to take Fever Bark with Efgartigimod alfa-fcab?

We do not list a known interaction between Fever Bark and Efgartigimod alfa-fcab. 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 Fever Bark and Efgartigimod alfa-fcab combination checked?

Interactions in our licensed database are recorded against drug classes. Efgartigimod alfa-fcab is filed under 1 classification, and Fever Bark has documented interactions with 9 drug classes — none of Efgartigimod alfa-fcab'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 Fever Bark interact with any other medications?

Yes. Fever Bark has 801 documented drug interactions in our database — Efgartigimod alfa-fcab 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 Efgartigimod alfa-fcab interact with any supplements?

Yes. Efgartigimod alfa-fcab has documented interactions with 53 supplements in our database — Fever Bark is not one of them. The Efgartigimod alfa-fcab interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Fever Bark monograph Uses, safety profile, and every drug interaction in one place Efgartigimod alfa-fcab Injection drug information The full plain-English guide to this medication Efgartigimod alfa-fcab supplement interactions Every supplement checked against Efgartigimod alfa-fcab, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 50 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Efgartigimod alfa-fcab and Fever Bark?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.