Prescription Clinical MonographPrescription Therapeutic Agent
Verified Evidence Sources: openFDA & NLM MedlinePlus

Trandolapril and Verapamil

Comprehensive clinical interaction and dietary monograph for Trandolapril and Verapamil (Trandolapril and Verapamil).

Generic Active Chemical: Trandolapril and Verapamil
Brand Formulations:Tarka (containing Trandolapril, Verapamil)

Kitchen Food, Drink & Dietary Conflicts

Biochemical interactions with common foods, beverages & cooking ingredients
4 Flagged Foods
Official Patient Dietary Instruction (NLM MedlinePlus)

Trandolapril and verapamil may cause an upset stomach. Take trandolapril and verapamil with food or milk. Talk to your doctor before using salt substitutes containing potassium. If your doctor prescribes a low-salt or low-sodium diet, follow these directions carefully.

CRITICAL

Grapefruit / Pomelo (Citrus paradisi / Citrus maxima)

NutriDive Kitchen Food Biochemical Ontology & openFDA
Bioactive Compound:Furanocoumarins (Bergamottin, 6',7'-Dihydroxybergamottin)
Biological Target:Intestinal Cytochrome P450 3A4 (CYP3A4) & P-glycoprotein
Clinical Mechanism:

Destroys enterocyte CYP3A4 enzymes, collapsing first-pass drug metabolism and causing up to 12-fold spikes in bioavailability for oral CYP3A4 substrates (statins, calcium channel blockers, immunosuppressants, PDE5 inhibitors).

Patient Actionable Rule:Completely avoid grapefruit, pomelos, and Seville oranges for the entire duration of therapy. Normal intestinal CYP3A4 enzyme turnover takes up to 72 hours to regenerate after ingestion.
CRITICAL

Potassium-Enriched Salt Substitutes (Low-Sodium Table Salt)

NutriDive Kitchen Food Biochemical Ontology & openFDA
Bioactive Compound:Potassium Chloride (KCl)
Biological Target:Renal Cortical Collecting Duct Electrophysiology
Clinical Mechanism:

Provides 500-1400 mg potassium per 1/4 teaspoon. When renal potassium excretion is suppressed by ACE inhibitors, ARBs, or aldosterone antagonists (spironolactone), acute severe hyperkalemia (>6.5 mEq/L) can trigger sudden flaccid paralysis and fatal ventricular fibrillation.

Patient Actionable Rule:Strictly verify ingredients of low-sodium seasonings. Avoid potassium-chloride based salt alternatives completely if taking Lisinopril, Losartan, or Spironolactone.
HIGH

Dairy Milk, Yogurt & Calcium-Enriched Foods

NutriDive Kitchen Food Biochemical Ontology & openFDA
Bioactive Compound:Ionic Calcium (Ca2+) & Casein Micelles
Biological Target:Intestinal Chelation & Luminal Complexation
Clinical Mechanism:

Divalent calcium binds fluoroquinolone (ciprofloxacin) and tetracycline (doxycycline) antibiotics into unabsorbable ring complexes, reducing systemic antibacterial coverage by up to 90% and causing therapy failure.

Patient Actionable Rule:Separate all dairy ingestion from oral antibiotics, bisphosphonates, and thyroid medications by at least 2 to 4 hours.
HIGH

Alcoholic Beverages (Beer, Wine, Spirits)

NutriDive Kitchen Food Biochemical Ontology & openFDA
Bioactive Compound:Ethanol
Biological Target:GABA-A Receptors, Hepatic CYP2E1 & Gluconeogenesis
Clinical Mechanism:

Multiplies respiratory depression and profound sedation with opioids and sedatives; blocks hepatic lactate uptake with metformin (lactic acidosis); triggers acute disulfiram-like vomiting and tachycardia with metronidazole; and accelerates dose-dumping in extended-release capsules.

Patient Actionable Rule:Completely abstain from alcohol while taking metronidazole, cephalosporins, prescription sedatives, or empty-stomach metformin.

Prescription & OTC Drug Interactions (DDI)

Documented pharmacological conflicts & contraindicated co-prescriptions
1 Warning Classes
HIGH RISK

NSAIDs (Ibuprofen, Naproxen) & Non-Cardioprotective Analgesics

openFDA SPL Section 7 (Drug Interactions)

Mechanism: Inhibition of renal vasodilatory prostaglandins (PGI2, PGE2) causes afferent arteriolar vasoconstriction, blunts blood pressure control, and increases risk of acute kidney injury (AKI).

Clinical Consequence: Loss of blood pressure reduction, fluid retention, or acute renal hemodynamic compromise.
Physician Precaution: Consult your physician before taking OTC pain relievers. Acetaminophen may be preferred for occasional pain depending on liver status.

Dietary Supplements, Herbs & Minerals (DNI)

Interactions with over-the-counter vitamins, minerals, and herbal preparations
1 Monitored
CRITICAL

Potassium Supplements (Potassium Chloride, Gluconate, Citrate)

NIH Office of Dietary Supplements (ODS) & NLM MedlinePlus
Biological Target: Myocardial Resting Membrane Potential & Cardiac Conduction

Direct renin inhibition suppresses downstream aldosterone secretion, preventing physiological urinary potassium excretion. Exogenous potassium supplements directly provoke dangerous serum hyperkalemia.

Guidance & Spacing:Do not take oral potassium supplements unless specifically prescribed and monitored by your physician.

Chronotherapy & Meal Administration Protocols

Optimal absorption, meal-timing rules & GI tolerability protocols
0 Protocols

Frequently Researched Drug-Substance Combinations

Explore pairwise interaction dossiers and laboratory safety analyses
Multi-Substance Interactive Radar

Taking Trandolapril and Verapamil alongside daily coffee, supplements, or other medications?

Add all your daily medications, foods (Dairy, Spinach, Coffee, Grapefruit), and botanicals (Ashwagandha, Curcumin, Melatonin) into the SafeStack interactive engine to run full multi-way synergy collision analysis in real time.

Launch SafeStack Radar with Trandolapril and Verapamil→
Authoritative Clinical Evidence & Regulatory Sources

Data on this clinical monograph is compiled from the U.S. National Library of Medicine (MedlinePlus), openFDA Structured Product Labeling (SPL Section 7 Drug Interactions), the NIH Office of Dietary Supplements (ODS), and Krause and Mahan's Food & Nutrition Care Process.