Drug & supplement interaction

Cocoa + Diltiazem, Enalapril

Diltiazem, Enalapril brand name: Teczem.

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

Diltiazem, Enalapril falls into 3 drug categories that Cocoa can interact with; the most serious is rated moderate. Theoretically, taking cocoa with antihypertensive drugs might increase the risk of hypotension.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cocoa and Diltiazem, Enalapril

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Cocoa interacts with whole categories of medication. Diltiazem, Enalapril falls into 3 of those categories, so it can interact with Cocoa in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 3

Why this applies to Diltiazem, Enalapril

Diltiazem, Enalapril falls under ANTIHYPERTENSIVE DRUGS — the group Cocoa interacts with.

Theoretically, taking cocoa with antihypertensive drugs might increase the risk of hypotension.
Clinical research shows that cocoa can modestly decrease blood pressure in hypertensive and normotensive patients.
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

Teczem combines two blood pressure medicines: diltiazem (a calcium channel blocker) and enalapril (an ACE inhibitor). Both lower your blood pressure on their own. Here's the thing about cocoa: the flavanols in it may help blood vessels relax a little, which can nudge your blood pressure down too. So in theory, pairing them could add up and push your pressure lower than intended.

If that happens, you might feel dizzy, lightheaded, tired, or get a headache, especially when standing up quickly. I want to be honest though, this concern is mostly theoretical and based on how these things work, not strong real-world reports. A square of dark chocolate now and then is unlikely to matter. Concentrated cocoa supplements are the bigger question, so check with your pharmacist or doctor before starting one.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Taubert D, Berkels R, Roesen R, Klaus W. Chocolate and blood pressure in elderly individuals with isolated systolic hypertension. JAMA 2003;290:1029-30.. PubMed
  2. Grassi D, Necozione S, Lippi C, et al. Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives. Hypertension 2005;46:398-405. PubMed
  3. Taubert D, Roesen R, Schomig E. Effect of cocoa and tea intake on blood pressure: a meta-analysis. Arch Intern Med 2007;167:626-34. PubMed
  4. Taubert D, Roesen R, Lehmann C, et al. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA 2007;298:49-60. PubMed
  5. Hooper L, Kay C, Abdelhamid A, et al. Effects of chocolate, cocoa, and flavan-3-ols on cardiovascular health: a systematic review and meta-analysis of randomized trials. Am J Clin Nutr 2012;95:740-51. PubMed
  6. Hooper, L., Kroon, P. A., Rimm, E. B., Cohn, J. S., Harvey, I., Le Cornu, K. A., Ryder, J. J., Hall, W. L., and Cassidy, A. Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2008;88 PubMed
  7. Desch, S., Schmidt, J., Kobler, D., Sonnabend, M., Eitel, I., Sareban, M., Rahimi, K., Schuler, G., and Thiele, H. Effect of cocoa products on blood pressure: systematic review and meta-analysis. Am J Hypertens. 2010;23(1):97-103. PubMed
  8. Ried, K., Sullivan, T., Fakler, P., Frank, O. R., and Stocks, N. P. Does chocolate reduce blood pressure? A meta-analysis. BMC.Med 2010;8:39. PubMed
  9. Shrime, M. G., Bauer, S. R., McDonald, A. C., Chowdhury, N. H., Coltart, C. E., and Ding, E. L. Flavonoid-rich cocoa consumption affects multiple cardiovascular risk factors in a meta-analysis of short-term studies. J Nutr 2011;141(11):1982-1988. PubMed
  10. Sudarma, V., Sukmaniah, S., and Siregar, P. Effect of dark chocolate on nitric oxide serum levels and blood pressure in prehypertension subjects. Acta Med.Indones. 2011;43(4):224-228.
  11. Ried, K., Sullivan, T. R., Fakler, P., Frank, O. R., and Stocks, N. P. Effect of cocoa on blood pressure. Cochrane.Database.Syst.Rev. 2012;8:CD008893. PubMed
  12. Jafarnejad S, Salek M, Clark CCT. Cocoa consumption and blood pressure in middle-aged and elderly subjects: a meta-analysis. Curr Hypertens Rep. 2020;22(1):1. PubMed
  13. Balayssac-Siransy E, Ouattara S, Boka KJM, et al. Dose-effect relation between regular consumption of 100% cocoa powder and blood pressure in young, healthy black Africans. Physiol Rep 2021;9(20):e15070. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS

2 of 3

Diltiazem, Enalapril also falls under CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS.

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Cocoa contains caffeine. Caffeine is metabolized by cytochrome P450 1A2 (CYP1A2),. Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from cocoa and increase caffeine levels.
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 a twist worth knowing: this combo pill (diltiazem plus enalapril) doesn't make your body absorb less cocoa. It's actually the other way around. Diltiazem can gently slow down a liver enzyme called CYP1A2, which is the same enzyme that clears caffeine out of your system. Since cocoa carries a little caffeine, that caffeine may hang around longer than usual.

In plain terms, you might feel more of caffeine's effects, like jitteriness, a faster heartbeat, or trouble sleeping. The good news is this is a theoretical concern based on how the drug works, not strong proof, and a normal serving of chocolate or a hot cocoa is unlikely to cause trouble. Concentrated cocoa supplements are where I'd be more cautious. If you notice your heart racing or feel wired, check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Weisburger JH. Tea and health: the underlying mechanisms. Proc Soc Exp Biol Med 1999;220:271-5. PubMed
  2. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63. PubMed
  3. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
  4. Kot, M. and Daniel, W. A. Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes. Pharmacol Rep. 2009;61(6):1216-1220. PubMed
  5. Wojcikowski, J. and Daniel, W. A. Perazine at therapeutic drug concentrations inhibits human cytochrome P450 isoenzyme 1A2 (CYP1A2) and caffeine metabolism--an in vitro study. Pharmacol Rep. 2009;61(5):851-858. PubMed
  6. Wang, X. and Yeung, J. H. Effects of the aqueous extract from Salvia miltiorrhiza Bunge on caffeine pharmacokinetics and liver microsomal CYP1A2 activity in humans and rats. J Pharm Pharmacol 2010;62(8):1077-1083.
  7. Kot M, Daniel WA. Caffeine as a marker substrate for testing cytochrome P450 activity in human and rat. Pharmacol Rep 2008;60:789-97.
  8. Kjaerstad MB, Nielsen F, Nohr-Jensen L, et al. Systemic uptake of miconazole during vaginal suppository use and effect on CYP1A2 and CYP3A4 associated enzyme activities in women. Eur J Clin Pharmacol 2010;66:1189-97. PubMed
  9. Goh BC, Reddy NJ, Dandamudi UB, et al. An evaluation of the drug interaction potential of pazopanib, an oral vascular endothelial growth factor receptor tyrosine kinase inhibitor, using a modified Cooperstown 5+1 cocktail in patients with advanced solid t
  10. Chen Y, Kang Z, Yan J, et al. Liu wei di huang wan, a well-known traditional Chinese medicine induces CYP1A2 while suppressing CYP2A6 and N-acetyltransferase 2 acivities in man. J Ethnopharmacol 2010;132:213-8.
  11. Suzuki S, Murayama Y, Sugiyama E, et al. Estimating pediatric doses of drugs metabolized by cytochrome P450 (CYP) isozymes, based on physiological liver development and serum protein levels. Yakugaku Zasshi 2010;130:613-20. PubMed
  12. Chien CF, Wu YT, Lee WC, et al. Herb-drug interaction of Andrographis paniculata extract and andrographolide on the pharmacokinetics of theophylline in rats. Chem Biol Interact 2010;184:458-65. PubMed
  13. Mills BM, Zaya MJ, Walters RR, et al. Current cytochrome P450 phenotyping methods applied to metabolic drug -drug interaction prediction in dogs. Drug Metab Dispos 2010;38:396-404. PubMed
  14. Turpault S, Brian W, Van Horn R, et al. Pharmacokinetic assessment of a five-probe cocktail for CYPs 1A2, 2C9, 2C19, 2D6, and 3A. Br J Clin Pharmacol 2009;68:928-35. PubMed
  15. Filimonova AA, Ziganshina LE, Ziganshin AU, Chichirov AA. On the possibility of patient phenotyping on the basis of cytochrome p-450 1A2 isoenzyme activity using caffeine as the test substrate. Eksp Klin Farmakol 2009;72:61-5.
  16. Jenkins J, Williams D, Deng Y, et al. Eltrombopag, an oral thrombopoietin receptor agonist, has no impact on the pharmacokinetic profile of probe drugs for cytochrome P450 isoenzymes CYP3A4, CYP1A2, CYP2C9 and CYP2C19 in healthy men: a cocktail analysis.
  17. Perera, V., Gross, A. S., and McLachlan, A. J. Caffeine and paraxanthine HPLC assay for CYP1A2 phenotype assessment using saliva and plasma. Biomed.Chromatogr. 2010;24(10):1136-1144. PubMed
  18. Izzo, A. A. and Ernst, E. Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs 2009;69(13):1777-1798. PubMed
Moderate

ACE INHIBITORS (ACEIs)

3 of 3

Diltiazem, Enalapril also falls under ACE INHIBITORS (ACEIs).

Theoretically, taking cocoa with ACEIs might increase the risk of adverse effects.
Human research shows that dark chocolate can inhibit ACE. Additionally, prolonged angioedema in an elderly patient on an ACE inhibitor was precipitated with intake of diabetic chocolate.
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

Your medicine, Teczem, combines diltiazem with enalapril, and it's the enalapril part (an ACE inhibitor) that matters here. The thinking is that cocoa flavanols may gently push blood vessels to relax, and there's some lab evidence that dark chocolate can lightly block the ACE enzyme too. Since enalapril already does that, stacking the two could nudge your blood pressure a little lower than expected, leaving you lightheaded, tired, or dizzy when you stand up.

Honestly, this is mostly theoretical, based on pharmacology and one unusual case report of swelling (angioedema). A normal piece of chocolate is very unlikely to cause trouble. I'd just be more thoughtful with concentrated cocoa supplements, and check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Kannayiram, A., Rezaie, A., and Hadi, S. Chocolate-induced prolonged angiooedema in an elderly patient. Age Ageing 2008;37(4):479-480. PubMed
  2. Persson, I. A., Persson, K., Hagg, S., and Andersson, R. G. Effects of cocoa extract and dark chocolate on angiotensin-converting enzyme and nitric oxide in human endothelial cells and healthy volunteers--a nutrigenomics perspective. J Cardiovasc.Pharmac 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

Cocoa Also Interacts With Other Medications

Cocoa has 634 moderate, 26 minor known drug interactions in our database — the Diltiazem, Enalapril one above is among them. If you take anything else, check it against the full list below.

Moderate 634 Minor 26 No known interaction 2,170 (incl. Diltiazem, Enalapril)
Taking anything else?

Check Another of Your Medications Against Cocoa

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

Everything else you take

See Every Supplement That Interacts With Diltiazem, Enalapril

This page covers Cocoa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diltiazem, Enalapril page lists 271 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Coleus (major).

By severity: 9 major · 220 moderate · 42 minor.

From our pharmacist’s overview on the Diltiazem, Enalapril page

“Anyone taking Teczem (diltiazem with enalapril) for blood pressure should know that most of the 271 supplements with an interaction on file hit the same targets as the drug itself. The bulk either add to its blood-pressure-lowering effect or change how the body handles diltiazem, which is processed by an enzyme called CYP3A4.”

Reviewed by 2 · Jul 18, 2026

Open the Diltiazem, Enalapril interaction page

One more smart check

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

We hold 844 real supplement products containing Cocoa, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cocoa. Your product may carry other ingredients that interact with Diltiazem, Enalapril too, on top of Cocoa — 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 Cocoa and Diltiazem, Enalapril 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 Cocoa
Top 25%

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

29 days ago today
Medication Diltiazem, Enalapril
Steady interest

#1,846 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 Cocoa

What is Cocoa?

Cocoa
  • Heart and blood vessel health
  • High blood pressure
  • High cholesterol
  • Mental focus and mood
  • Skin moisturizing (cocoa butter)

Cocoa is rich in plant compounds called flavanols that may modestly support blood vessel function and blood pressure, but most chocolate products are high in sugar, fat, and calories, which can offset any benefit. Enjoy cocoa as part of a balanced diet, and talk to your pharmacist before using concentrated cocoa supplements, especially if you have heart or blood pressure conditions.

Read the full Cocoa monograph & all interactions
Keep checking

Other Drugs & Cocoa

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

0Major
634Moderate
26Minor
2,169No known interaction
634 Moderate 26 Minor 2,169 No interaction
Moderate

634 interactions

Showing 60 of 634 moderate interactions — see all 634 on the Cocoa page.

Minor

26 interactions

No interaction 2,169 drugs checked — show the list

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

Showing the 60 most looked-up of 2,169 medications checked with no known interaction — see the full Cocoa list.

See the full Cocoa interactions page
See every supplement checked against Diltiazem, Enalapril, 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
Cocoa monograph › Uses, safety, and every drug interaction in one place Diltiazem, Enalapril supplement interactions › Every supplement checked against Diltiazem, Enalapril, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cocoa and Diltiazem, Enalapril Together: Common Questions

Can you take Cocoa with Diltiazem, Enalapril?
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 3 interactions listed for Cocoa and Diltiazem, Enalapril?
Diltiazem, Enalapril belongs to more than one drug category, and Cocoa 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 Cocoa and Diltiazem, Enalapril 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

Still Have a Question About Diltiazem, Enalapril and Cocoa?

Our pharmacists answer your medication & supplement questions — free.

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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.