Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.
Diltiazem is a calcium channel blocker of the benzothiazepine group that acts on both the heart and blood vessels: it slows the heart rate and the conduction of the heartbeat, and relaxes arteries. It is used for high blood pressure, angina and to slow fast heart rhythms such as atrial fibrillation, and as a cream for anal fissures. It is sold as Cardizem, Tiazac and Dilacor, among other names.
Diltiazem is broken down by CYP3A4, which it also blocks, and partly by CYP2D6. The few gene studies listing it, mostly from blood pressure trials, looked at the beta-1 receptor gene ADRB1, NEDD4L and PLCD3 for blood pressure response and outcomes. The findings come from a few studies, and there is no CPIC or DPWG guideline.
Every published finding on gene variants and Diltiazem. Upload your DNA file to see which of these rows apply to you.
PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.
PLCD3 rs12946454: Level 3. Efficacy: Hypertension. 1.
Studies of how well it worked in people carrying a variant.
Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.
More drugs from the same category
Calan (Calcium Channel Blockers)
Calcium Channel Blockers (class) (Calcium Channel Blockers)
Cardene (Calcium Channel Blockers)
Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.
Content updated September 2026.
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