Supplements and Verapamil hydrochloride.
Verapamil hydrochloride, sold under the brand names Securon, Cordilox, Univer, is a calcium channel blocker: it relaxes vascular smooth muscle and reduces afterload.
Verapamil hydrochloride is a calcium channel blocker. The dihydropyridine subclass (amlodipine, felodipine, nifedipine) preferentially blocks arterial L-type channels and is prescribed mainly for hypertension. Verapamil and diltiazem sit outside the dihydropyridine family. They also affect cardiac conduction and are used for arrhythmia control. CYP3A4 metabolism applies across the class, so 3A4 inhibitors (grapefruit, and certain supplements at higher doses including curcumin, quercetin, and schisandra) can raise plasma levels by 20 to 40 percent. The side effect most often reported is ankle oedema, from preferential arteriolar dilation, and it scales with dose. Additive BP supplements (beetroot, hibiscus, garlic, CoQ10 at the studied doses) stack on top. Verapamil and diltiazem carry an additional interaction with CoQ10. This is the only adjacent cardiac class where the CoQ10 evidence is meaningful, since they have a small negative inotropic effect that CoQ10 marginally offsets.
Below are the 2 documented pairs we have explicitly assessed against Verapamil hydrochloride in the Distil database: 2 amber. The pairs cluster around 1 mechanism: Additive blood-pressure lowering. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Additive blood-pressure lowering
Beetroot lowers blood pressure through the nitric oxide pathway. Verapamil lowers blood pressure through calcium-channel blockade and also slows the heart rate. Used together, the combined blood-pressure effect tends to be larger than either alone. Watch for dizziness on standing in the first two weeks. If symptoms appear, tell your GP.
Spirulina has a mild blood-pressure-lowering effect of its own, shown in human trials. Verapamil lowers blood pressure through calcium-channel blockade and also slows the heart rate. Used together, the combined effect tends to be a little larger than the medicine alone. Watch for dizziness on standing in the first couple of weeks, and tell your GP if it happens so your dose can be reviewed.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
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