Drug & supplement interaction

Coca + Liothyronine

Liothyronine brand name: Cytomel.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Coca and Liothyronine 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Coca and Liothyronine

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 Liothyronine and Coca 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.

Coca safety at a glance

Coca overall Avoid Coca leaf naturally contains cocaine and is a controlled substance in most countries; only cocaine-free extract is legal as a flavoring.
Pregnancy Unsafe When inhaled or used orally. Coca, and the constituent cocaine, are contraindicated due to abortifacient and teratogenic effects. Coca use is also associated wi... Read the full pregnancy detail
Breastfeeding Unsafe When inhaled or used orally. Coca and the constituent, cocaine, are contraindicated. Cocaine is excreted into human milk and intoxication can occur in infants c... 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 Liothyronine and Coca? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Liothyronine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Liothyronine is filed under 2 classifications — thyroid hormone, oral drugs. Coca has documented interactions with 4 drug classes — the most serious being alcohol (ethanol) (major), nifedipine (procardia) (major) and antidiabetes drugs (moderate) — and none of Liothyronine’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

Coca Does Interact With Other Medications

Coca has 2 major, 257 moderate known drug interactions in our database — Liothyronine isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Coca

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

What to actually watch for

No Interaction Found — But Data Suggests Coca and Liothyronine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 3 of them are worth acting on rather than waiting out — marked below.

  • A heart attack Worth acting on Additional detail

    Coca

    “Orally, the cocaine constituent of coca can cause serious adverse effects. Cocaine use is associated with a high incidence of coronary artery disease or other myocardial disease. Up to 38% of cocaine users may have a defect in left ventricular filling.”

    Coca · Natural Medicines adverse-effect record, reported in arrhythmia.

    3 sources cited
    1. 9459. Roldan CA, Aliabadi D, Crawford MH. Prevalence of heart disease in asymptomatic chronic cocaine users. Cardiology 2001;95:25-30.. PubMed
    2. 17. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
    3. 6374. Heesch CM, Wilhelm CR, Ristich J, et al. Cocaine activates platelets and increases the formation of circulating platelet containing microaggregates in humans. Heart 2000;83:688-95. PubMed

    Liothyronine

    Listed in the ADVERSE REACTIONS section of the FDA label for Liothyronine. Read the label on DailyMed ›

  • Wheezing / Shortness of breath Worth acting on Additional detail

    Coca

    “Orally, the cocaine constituent of coca can cause serious adverse effects. Respiratory adverse effects include exacerbation of asthma, thermal airway injury, adult respiratory distress syndrome (ARDS), pneumothorax, pneumomediastinum, pulmonary thrombosis, bronchiolitis obliterans, pulmonary edema, pulmonary infiltrates, pulmonary vascular disease, and pulmonary hemorrhage (17).

    Intranasally, chronic cocaine abuse is…”

    Coca · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    2 sources cited
    1. 17. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
    2. 1258. Alexandrakis G, Tse DT, Rosa RH Jr, Johnson TE. Nasolacrimal duct obstruction and orbital cellulitis associated with chronic intranasal cocaine abuse. Arch Ophthalmol 1999;117:1617-22. PubMed

    Liothyronine

    Listed in the ADVERSE REACTIONS section of the FDA label for Liothyronine. Read the label on DailyMed ›

  • Anxiety or restlessness / Headache Additional detail

    Coca

    “Orally, the cocaine constituent of coca can cause serious adverse effects. Initially, the neurologic effects of coca can include euphoria, hyperactivity, and restlessness. Tremors, hyperreflexia, and seizures can develop later on. Finally, coma, hyporeflexia, and death may occur. Cocaine can also cause migraine headaches, stroke, and intracranial and intracerebral hemorrhage (17,5092).”

    Coca · Natural Medicines adverse-effect record, reported in epilepsy.

    2 sources cited
    1. 17. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
    2. 5092. McEvoy AW, Kitchen ND, Thomas DG. Intracerebral haemorrhage in young adults: the emerging importance of drug misuse. BMJ 2000;320:1322-4.

    Liothyronine

    Listed in the ADVERSE REACTIONS section of the FDA label for Liothyronine. Read the label on DailyMed ›

Reported for Coca but not commonly for Liothyronine: severe muscle breakdown, low blood sugar, low mood and blood clots.

Effects for Liothyronine come from the ADVERSE REACTIONS section of its FDA label; effects for Coca come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Coca in Pregnancy & Breastfeeding

Pregnancy Unsafe

When inhaled or used orally. Coca, and the constituent cocaine, are contraindicated due to abortifacient and teratogenic effects. Coca use is also associated with a high incidence of sudden infant death syndrome (SIDS).

Lactation Unsafe

When inhaled or used orally. Coca and the constituent, cocaine, are contraindicated. Cocaine is excreted into human milk and intoxication can occur in infants consuming human milk after recent exposure to cocaine.

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 Coca or Liothyronine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Coca or Liothyronine, 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 Liothyronine

This page covers Coca only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Liothyronine page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate) and Ascophyllum Nodosum (moderate).

By severity: 2 major · 26 moderate · 10 minor.

From our pharmacist’s overview on the Liothyronine page

“Liothyronine (Cytomel) is the active thyroid hormone T3, and it does not tolerate interference well. Of the 38 supplements and herbs on file, 21 act on thyroid function itself, some amplifying the hormone and others blunting it, iodine-rich seaweeds able to swing either way.”

Reviewed by 2 · Jul 18, 2026

Open the Liothyronine interaction page

How much people look this up

Where Coca and Liothyronine 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 Coca
Steady interest

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

29 days ago today
Medication Liothyronine
Top half

#1,033 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 Coca reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Coca and Liothyronine 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 .
Supplement

About Coca

What is Coca?

Coca
  • Altitude sickness
  • Fatigue and low energy
  • Appetite and hunger suppression
  • Digestive upset
  • Flavoring agent in foods and drinks

Coca is a South American plant best known as the natural source of cocaine. While the leaves have a long history of traditional use for altitude sickness, fatigue, and hunger, the whole plant contains cocaine and other alkaloids that make it legally controlled and potentially dangerous in most countries. Only decocainized (cocaine-free) coca extract is used in foods, and there is little reliable evidence to recommend coca as a supplement.

Erythroxylum coca · Erythroxylaceae · Leaves (and decocainized extract) · Tea (mate de coca), chewed leaves, decocainized extract used as a flavoring

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

Coca: dosing

There is no established safe or standard dose of coca as a dietary supplement, and the cocaine-containing leaf is illegal in most countries. We do not recommend a dose.For products that use cocaine-free coca extract as a flavoring, follow the directions on the product label.

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

Read the full Coca monograph & all interactions
Medication

About Liothyronine

What Is Liothyronine Used For?

Brand name: Cytomel

Liothyronine (available as tablets under the brand names Cytomel, Liomny, and Liothyronine Sodium, and as an injection under Liothyronine Sodium and Triostat) is primarily used to treat hypothyroidism (an underactive thyroid) across all its forms — whether the cause is in the thyroid itself, the pituitary gland, or the hypothalamus, and whether it was present at birth or developed over time.

The oral tablets are also used alongside surgery and radioiodine therapy to suppress TSH (thyroid-stimulating hormone) in people with well-differentiated thyroid cancer, and as a diagnostic agent in thyroid suppression tests. Liothyronine sodium injection is specifically indicated for myxedema coma (a life-threatening form of severe hypothyroidism) and may be used in patients who are allergic to thyroid products derived from pork or beef.

Most-Reported Side Effects for Liothyronine

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Headache 885 reports
Fatigue 849 reports
Nausea 585 reports
Dyspnea 559 reports
Hypertension 467 reports
See full Liothyronine drug information
Keep checking

Other Drugs & Coca

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

2Major
257Moderate
0Minor
2,570No known interaction
Major

2 interactions

Moderate

257 interactions

Showing 60 of 257 moderate interactions — see all 257 on the Coca page.

No interaction 2,570 drugs checked — show the list
Evidence & sources

Coca References

The 15 references that drive our Coca 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.

  1. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Alexandrakis G, Tse DT, Rosa RH Jr, Johnson TE. Nasolacrimal duct obstruction and orbital cellulitis associated with chronic intranasal cocaine abuse. Arch Ophthalmol 1999;117:1617-22. PubMed
  4. McEvoy AW, Kitchen ND, Thomas DG. Intracerebral haemorrhage in young adults: the emerging importance of drug misuse. BMJ 2000;320:1322-4.
  5. Potter SM, Zelazo PR, Stack DM, Papageorgiou AN. Adverse effects of fetal cocaine exposure on neonatal auditory information processing. Pediatrics 2000;105:E40.. PubMed
  6. Bolla KI, Funderburk FR, Cadet JL. Differential effects of cocaine and cocaine alcohol on neurocognitive performance. Neurology 2000;54:2285-92. PubMed
  7. Heesch CM, Wilhelm CR, Ristich J, et al. Cocaine activates platelets and increases the formation of circulating platelet containing microaggregates in humans. Heart 2000;83:688-95. PubMed
  8. Favier R, Caceres E, Guillon L, et al. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J Appl Physiol 1996;81:1901-7.. PubMed
  9. Favier R, Caceres E, Sempore B, et al. Fluid regulatory hormone response to exercise after coca-induced body fluid shifts. J Appl Physiol 1997;83:376-82.. PubMed
  10. Buck AA, Sasaki TT, Hewitt JJ, Macrae AA. Coca chewing and health. An epidemiologic study among residents of a Peruvian village. Am J Epidemiol 1968;88:159-77.. PubMed
  11. Roldan CA, Aliabadi D, Crawford MH. Prevalence of heart disease in asymptomatic chronic cocaine users. Cardiology 2001;95:25-30.. PubMed
  12. Galarza Guzman M, Penaloza Imana R, Echalar Afcha L, et al. Effects of coca chewing on glucose tolerance test. Medicina (B Aires) 1997;57(3):261-4.
  13. Spielvogel H, Rodriguez A, Sempore B, et al. Body fluid homeostasis and cardiovascular adjustments during submaximal exercise: influence of chewing coca leaves. Eur J Appl Physiol Occup Physiol 1997;75(5):400-6. PubMed
  14. Spielvogel, H., Caceres, E., Koubi, H., Sempore, B., Sauvain, M., and Favier, R. Effects of coca chewing on metabolic and hormonal changes during graded incremental exercise to maximum. J.Appl.Physiol 1996;80(2):643-649. PubMed
  15. Favier, R., Caceres, E., Koubi, H., Sempore, B., Sauvain, M., and Spielvogel, H. Effects of coca chewing on hormonal and metabolic responses during prolonged submaximal exercise. J.Appl.Physiol 1996;80(2):650-655. 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 Coca and Liothyronine Together: Common Questions

Is it safe to take Coca with Liothyronine?
We do not list a known interaction between Coca and Liothyronine. 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.
Do Coca and Liothyronine have any of the same side effects?
Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Coca and Liothyronine combination checked?
Interactions in our licensed database are recorded against drug classes. Liothyronine is filed under 2 classifications, and Coca has documented interactions with 4 drug classes — none of Liothyronine'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 Coca interact with any other medications?
Yes. Coca has 259 documented drug interactions in our database — Liothyronine 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 Liothyronine interact with any supplements?
Yes. Liothyronine has documented interactions with 38 supplements in our database — Coca is not one of them. The Liothyronine interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Liothyronine and Coca?

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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.