Niacin + Trandolapril, Verapamil
Trandolapril, Verapamil brand name: Tarka.
Trandolapril, Verapamil falls into 2 drug categories that Niacin can interact with; the most serious is rated moderate. Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
Read the full interaction reportNiacin and Trandolapril, Verapamil
These two interact in 2 distinct ways. Each one is explained separately below.
Why Are There 2 Interactions?
Niacin interacts with whole categories of medication. Trandolapril, Verapamil falls into 2 of those categories, so it can interact with Niacin in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
ANTIHYPERTENSIVE DRUGS
1 of 2Why this applies to Trandolapril, Verapamil
Trandolapril, Verapamil falls under ANTIHYPERTENSIVE DRUGS — the group Niacin interacts with.
The vasodilating effects of niacin can cause hypotension. Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients.
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.
Tarka combines two blood-pressure-lowering medicines: trandolapril (an ACE inhibitor) and verapamil (a calcium channel blocker). Here the concern isn't about how your liver breaks the drug down. Instead, it's that high-dose niacin can widen your blood vessels on its own, which lowers blood pressure. Stack that on top of a medicine already designed to bring your pressure down and the two effects can add up.
If your blood pressure drops too low, you might feel dizzy, lightheaded, tired, or flushed, especially when you stand up quickly. This is a theoretical and modest concern, and the small amounts of niacin in food or a basic multivitamin are very unlikely to matter. The flushing-dose or cholesterol-dose niacin is where I'd be watchful. Please check with your pharmacist or doctor before starting it.
- American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
- McKenney J. New perspectives on the use of niacin in the treatment of lipid disorders. Arch Intern Med 2004;164:697-705. PubMed
- Gadegbeku CA, Dhandayuthapani A, Shrayyef MZ, Egan BM. Hemodynamic effects of nicotinic acid infusion in normotensive and hypertensive subjects. Am J Hypertens. 2003;16(1):67-71. PubMed
- Aramwit P, Srisawadwong R, Supasyndh O. Effectiveness and safety of extended-release nicotinic acid for reducing serum phosphorus in hemodialysis patients. J Nephrol. 2012 May-Jun;25(3):354-62. PubMed
HEPATOTOXIC DRUGS
2 of 2Trandolapril, Verapamil also falls under HEPATOTOXIC DRUGS.
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses. Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin.
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.
Here's the thing to know about pairing high-dose niacin with Tarka (the combo pill of trandolapril and verapamil). This isn't about niacin changing how the medicine works or how strong its blood-pressure effect is. The concern is the liver. Niacin in large, drug-like doses can occasionally stress the liver, and Tarka is also processed by the liver, so in theory using both could add up and raise the chance of liver irritation.
I'll be honest, this is a theoretical concern based on how these work, not something proven to happen often. Everyday amounts of niacin from food or a regular multivitamin are very unlikely to matter. The risk leans toward high-dose, especially sustained-release, niacin. Watch for yellowing skin or eyes, dark urine, belly pain, or unusual tiredness, and check with your pharmacist or doctor before starting high-dose niacin.
- American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
- Bays HE, Dujovne CA. Drug interactions of lipid-altering drugs. Drug Saf 1998;19:355-71. PubMed
- Rader JI, Calvert RJ, Hathcock JN. Hepatic toxicity of unmodified and time-release preparations of niacin. Am J Med 1992;92:77-81. PubMed
- Etchason JA, Miller TD, Squires RW, et al. Niacin-induced hepatitis: a potential side effect with low-dose time-release niacin. Mayo Clin Proc. 1991;66(1):23-8. PubMed
- Henkin Y, Johnson KC, Segrest JP. Rechallenge with crystalline niacin after drug-induced hepatitis from sustained-release niacin. JAMA. 1990;264(2):241-3. DOI
- Henkin Y, Oberman A, Hurst DC, Segrest JP. Niacin revisited: clinical observations on an important but underutilized drug. Am J Med. 1991;91(3):239-46. PubMed
- Bassan M. A case for immediate-release niacin. Heart Lung. 2012 Jan-Feb;41(1):95-8. PubMed
- Nawaz N, Mistretta T, Karime C, Lewis J, Wolf E. Cholestatic Drug-Induced Liver Injury in a Patient Taking High-Dose Niacin for Hyperlipidemia. J Investig Med High Impact Case Rep 2024;12:23247096231224349. PubMed
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Niacin Also Interacts With Other Medications
Niacin has 726 moderate known drug interactions in our database — the Trandolapril, Verapamil one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Niacin
We haven’t checked that one against Niacin yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Niacin. Pick one to open its full report.
See Every Supplement That Interacts With Trandolapril, Verapamil
This page covers Niacin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Trandolapril, Verapamil page lists 304 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 Beer (major).
By severity: 11 major · 250 moderate · 43 minor.
From our pharmacist’s overview on the Trandolapril, Verapamil page
“This is one of the supplement lists I would want a patient to read closely, not skim. Tarka combines trandolapril and verapamil to lower blood pressure, and most of these interactions pull on that same lever, either dropping pressure further than intended or working against the medicine altogether.”
Reviewed by 2 · Jul 18, 2026
Taking Niacin as Part of a Dietary Supplement Product? Check It for Interactions
We hold 933 real supplement products containing Niacin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Niacin. Your product may carry other ingredients that interact with Trandolapril, Verapamil too, on top of Niacin — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Niacin and Trandolapril, Verapamil 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.
#196 of 1,452 supplements looked up here in the last 7 days
#445 of 2,830 medications looked up here in the last 7 days
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.
About Niacin
What is Niacin?
- High cholesterol
- Vitamin B3 deficiency (pellagra)
- Heart health support
- General energy and metabolism
Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescription-strength niacin has been used to adjust cholesterol levels, but high doses can cause flushing and other side effects and should only be taken under medical supervision. Always talk with a pharmacist or doctor before using high-dose niacin supplements.
Other Drugs & Niacin
Browse every other medication we’ve checked against Niacin — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
726 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Nifedipine ›
- Ibuprofen ›
- Aspirin ›
- Insulin (rdna) ›
- Naproxen ›
- Doxycycline ›
- Minocycline ›
- Propranolol ›
- Tetracycline ›
- Levothyroxine ›
- Amoxicillin ›
- Hydrochlorothiazide ›
- Testosterone ›
- Verapamil ›
- Fenofibrate ›
- Levonorgestrel ›
- Quinidine ›
- Cyclosporine ›
- Glyburide ›
- Insulin (pork) ›
- Methyltestosterone ›
- Ciprofloxacin ›
- Nicotine ›
- Phenytoin ›
- Allopurinol ›
- Carbamazepine ›
- Diclofenac Potassium ›
- Dipyridamole ›
- Hydralazine ›
- Insulin (human) ›
- Acetaminophen ›
- Conjugated Estrogens ›
- Ketoprofen ›
- Methotrexate ›
- Nitrofurantoin ›
- Ofloxacin ›
- Propoxyphene ›
- Rifampin ›
- Testosterone Undecanoate ›
- Trichlormethiazide ›
- Acarbose ›
- Bendroflumethiazide ›
- Bivalirudin ›
- Dapsone ›
- Doxycycline Hyclate ›
- Duloxetine ›
- Eltrombopag ›
- Insulin Glargine ›
- Interferon Alfa-2b ›
- Interferon Beta-1b ›
- Isoniazid ›
- Itraconazole ›
- Levofloxacin ›
- Levothyroxine Sodium ›
- Liotrix ›
- Lisinopril ›
- Metolazone ›
- Minoxidil ›
Showing 60 of 726 moderate interactions — see all 726 on the Niacin page.
No interaction 2,103 drugs checked — show the list
We also checked Niacin against these medications and found no known interaction in our sources. Open any page to confirm.
- Methylphenidate ›
- Sertraline ›
- Ivermectin ›
- Abemaciclib ›
- Escitalopram ›
- Tadalafil ›
- Docusate ›
- Hydroxyurea ›
- Methamphetamine ›
- Valacyclovir ›
- Sumatriptan ›
- Prednisone ›
- Lisdexamfetamine ›
- Amitriptyline ›
- Isotretinoin ›
- Bupropion ›
- Bendamustine ›
- Amphetamine ›
- Fluoxetine ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Gabapentin ›
- Dextroamphetamine ›
- Quetiapine ›
- Clonazepam ›
- Methylene Blue ›
- Omeprazole ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Diazepam ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Cyclopentolate ›
- Cephalexin ›
- Roxithromycin ›
- Levetiracetam ›
- Ezetimibe ›
- Phentermine, Topiramate ›
- Mirtazapine ›
- Dexmethylphenidate ›
- Finasteride ›
- Carbidopa, Levodopa ›
- Estrogen ›
- Pizotifen ›
- Daptomycin ›
- Pegunigalsidase Alfa-iwxj ›
- Venlafaxine ›
- Mitomycin ›
- Hexobarbitone ›
- Levodopa ›
- Bromocriptine ›
- Alprazolam ›
- Aripiprazole ›
- Finasteride, Tadalafil ›
- Flutemetamol F-18 ›
- Caffeine (otc Drug) ›
- Bentoquatam ›
- Cefaclor ›
Showing the 60 most looked-up of 2,103 medications checked with no known interaction — see the full Niacin list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Trandolapril, Verapamil Is Linked to Lower Levels of 2 Nutrients
Natural Medicines records Trandolapril, Verapamil as a medicine that can lower these. This is not an interaction with Niacin — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Trandolapril, Verapamil nutrient depletion report ›
Niacin is itself a nutrient we track — see which medications may deplete NIACIN.
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Niacin and Trandolapril, Verapamil Together: Common Questions
Can you take Niacin with Trandolapril, Verapamil?
Why are there 2 interactions listed for Niacin and Trandolapril, Verapamil?
How serious is the Niacin and Trandolapril, Verapamil interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.