Levamlodipine Drug Interactions: What to Avoid and What to Tell Your Doctor

Levamlodipine (brand name Conjupri) can interact with a number of commonly used medications and foods. Some interactions can increase the level of levamlodipine in your blood (increasing side effect risk), while others can reduce its effectiveness. Being informed about these interactions—and making sure your healthcare team knows everything you're taking—is an important part of staying safe on this medication.

How Levamlodipine Is Metabolized (Why Interactions Happen)

Levamlodipine is metabolized primarily by the liver using an enzyme system called CYP3A4. CYP3A4 is one of the most important drug-metabolizing enzymes in the body—it breaks down approximately 50% of all drugs on the market. Because levamlodipine depends on CYP3A4 for its metabolism, any drug that inhibits or induces this enzyme can significantly change levamlodipine's blood levels.

CYP3A4 inhibitors slow down the metabolism of levamlodipine → blood levels rise → increased side effects (especially low blood pressure and edema)

CYP3A4 inducers speed up the metabolism of levamlodipine → blood levels fall → reduced blood pressure control

Contraindicated Combination (Do Not Take Together)

There is one combination that is listed as contraindicated with levamlodipine:

Dantrolene (muscle relaxant used for malignant hyperthermia): Reports of cardiovascular collapse associated with marked hyperkalemia have been documented when dantrolene is combined with calcium channel blockers. This combination should be avoided.

Major Interactions (Avoid or Use Carefully)

Grapefruit and grapefruit juice: Grapefruit contains compounds that strongly inhibit CYP3A4 in the intestine, increasing levamlodipine blood levels. Avoid grapefruit or grapefruit juice while taking levamlodipine.

Strong CYP3A4 inhibitors: Medications such as ketoconazole (antifungal), itraconazole, clarithromycin (antibiotic), ritonavir, and other HIV protease inhibitors can significantly increase levamlodipine levels. If you must take these together, dose adjustments and close monitoring are needed.

Tucatinib (Tukysa, cancer medication): A strong CYP3A4 inhibitor. Avoid combining with levamlodipine if possible; reduce levamlodipine dose according to labeling if unavoidable.

Important Interactions (Modify Dose or Monitor Closely)

Simvastatin (Zocor): Levamlodipine inhibits the metabolism of simvastatin via CYP3A4. Coadministration increases simvastatin exposure, raising the risk of muscle problems (myopathy or rhabdomyolysis). FDA labeling states: limit simvastatin dose to 20 mg/day when taking levamlodipine.

Amiodarone (Pacerone, Nexterone — heart rhythm medication): A moderate CYP3A4 inhibitor. Increased levamlodipine levels possible; monitor for hypotension and edema.

Sildenafil (Viagra, Revatio) and other PDE-5 inhibitors: Both levamlodipine and sildenafil lower blood pressure. When used together, each works independently and blood pressure may fall more than expected. Monitor for dizziness, lightheadedness, or fainting.

Moderate CYP3A4 inhibitors: Including diltiazem, erythromycin, fluconazole, verapamil, and aprepitant. May increase levamlodipine levels; monitor blood pressure and symptoms.

Interactions That Reduce Levamlodipine Effectiveness (CYP3A4 Inducers)

These medications may reduce levamlodipine's blood pressure-lowering effect by speeding up its metabolism:

Rifampin (tuberculosis antibiotic) — strong inducer; may significantly reduce levamlodipine efficacy

Carbamazepine (Tegretol), phenytoin, phenobarbital — seizure medications that induce CYP3A4; monitor blood pressure closely

St. John's Wort — an herbal supplement that induces CYP3A4; avoid while taking levamlodipine

Other Medications That Interact (Additive Hypotension)

Several medications can add to levamlodipine's blood pressure-lowering effect, increasing the risk of hypotension:

Other antihypertensives (ACE inhibitors, ARBs, beta-blockers, diuretics)

Alpha-blockers (used for enlarged prostate)

Alcohol (can lower blood pressure and increase dizziness risk)

What About NSAIDs (Ibuprofen, Naproxen)?

NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve) can reduce the effectiveness of antihypertensive medications, including levamlodipine. They can also cause fluid retention and worsen edema. For patients on levamlodipine, avoid NSAIDs for routine pain management if possible. Acetaminophen (Tylenol) is generally a safer choice for pain relief.

What to Tell Your Doctor

Before starting levamlodipine, tell your doctor and pharmacist about every medication you take, including:

All prescription drugs (especially statins, heart rhythm medications, antivirals, antifungals, seizure medications)

Over-the-counter medications (especially NSAIDs and decongestants)

Herbal supplements (especially St. John's Wort)

Vitamins and dietary supplements

The Bottom Line

Levamlodipine's most important drug interactions involve CYP3A4—both drugs that increase its levels (inhibitors) and those that decrease them (inducers). The simvastatin interaction is especially important to know: the dose must be limited to 20 mg/day when co-prescribed. Always review your complete medication list with your prescriber and pharmacist when starting levamlodipine. For information on common side effects, see our guide on levamlodipine side effects.