12 Amlodipine Drug Interactions You Should Know

Amlodipine is a commonly prescribed calcium channel blocker medication used to treat high blood pressure as well as certain types of angina (chest pain) and coronary artery disease. It is available in tablet form, both as a generic and brand-name Norvasc. It is also available as a liquid, with the brand names Katerzia (oral suspension) and Norliqva (oral solution)......Read The Full Article>>.....Read The Full Article>>

If you are taking amlodipine, it’s important to be aware of potential drug interactions. Some interactions can be managed by monitoring for side effects and dose adjustment, while others should be avoided entirely.

This is not a comprehensive list of all drugs that may interact with amlodipine. Before starting treatment, be sure to share your medication history with your healthcare provider, including all over-the-counter (OTC) or prescription drugs and dietary supplements you are taking.
1. Alprazolam

Alprazolam, commonly known by the brand name Xanax, is a medication prescribed for anxiety or panic disorder. It is part of a class of drugs known as benzodiazepines.

Alprazolam and amlodipine are generally not prescribed together. This is because they have a drug interaction that causes increased levels of alprazolam in the body. This can cause more severe side effects, including prolonged sedation and breathing problems.

Instead of alprazolam, your healthcare provider may prescribe a different benzodiazepine that does not interact with amlodipine, such as Ativan (lorazepam). However, if you can’t avoid the combination, your healthcare provider may lower the dose of alprazolam and closely monitor you during treatment.
2. Barbiturates

Barbiturates, such as phenobarbital (a prescription drug used to treat certain types of seizures) may interact with amlodipine. Other examples of barbiturates include:

Methohexital
Mysoline (primidone)
Pentobarbital

These drugs interact with amlodipine by affecting how the body processes the drug, causing lower levels of amlodipine in the body. This may make amlodipine less effective.

People who take both a barbiturate and amlodipine may require a higher dose of amlodipine as well as close monitoring of their blood pressure. Your provider can give you medical advice on appropriate dosing.
3. Certain Antifungal Medications

Amlodipine may interact with certain antifungal medications (drugs used to treat fungal infections), such as:

Diflucan (fluconazole)
Ketoconazole
Sporanox (itraconazole)

When used in combination, antifungals can cause higher levels of amlodipine in the body. This can lead to a higher risk of toxicity, as well as edema (fluid retention) and hypotension (low blood pressure). If an antifungal and amlodipine must be prescribed together, your healthcare provider may need to lower your amlodipine dose and keep an eye on your blood pressure and fluid retention.
4. Certain Antibiotics

Some antibiotics, such as clarithromycin and erythromycin, may interact with amlodipine.

Clarithromycin (a macrolide antibiotic used to treat bacterial infections such as pneumonia) should not be combined with amlodipine, especially in older adults (65 years and older). This is because combining these medications can cause low blood pressure and kidney problems.

Older people are more susceptible to these drug interactions due to age-related changes in how drugs affect the body. Additionally, older individuals are more likely to have an existing chronic condition, such as kidney or liver disease.

Like clarithromycin, erythromycin (another macrolide antibiotic used to prevent or treat infections) can also interact with amlodipine and especially affect older adults.

If you do need to take either of these medications, your provider may need to adjust your amlodipine dose and closely monitor for any side effects, such as extremely low blood pressure and fluid retention. If you need a different macrolide antibiotic, your provider may instead prescribe Zithromax (azithromycin), which does not interact with amlodipine.

Amlodipine may also interact with Cipro (ciprofloxacin), a quinolone antibiotic used to treat bacterial infections such as pneumonia (a lung infection) and gonorrhea (a sexually transmitted infection). Older adults are at an increased risk of this interaction.

If ciprofloxacin and amlodipine are prescribed together, your amlodipine dose may require adjustment, and you will need to be closely monitored for reactions.
5. Certain Immunosuppressants

Immunosuppressants are medications that work on the immune system to prevent the body from rejecting a transplanted organ, such as a kidney or liver. Some immunosuppressants that can interact with amlodipine include:

Cyclosporine
Prograf (tacrolimus)
Rapamune (sirolimus)

Taking one of these immunosuppressants with amlodipine may lead to increased levels of the immunosuppressant in the body, which could increase the risk of side effects.

If the combination is prescribed together, your healthcare provider may adjust the immunosuppressant dosage and closely monitor you for reactions. Additionally, cyclosporine may also increase amlodipine levels in the body, which could lead to low blood pressure.

Genetic testing may be recommended in some cases to identify if you have the specific genotype (CYP3A5) that plays a role in this interaction.
6. Pseudoephedrine

Pseudoephedrine, the main ingredient in the brand name Sudafed, is an over-the-counter (OTC) medication used to relieve symptoms of a stuffy nose. It can be found alone as a single drug or as an active ingredient in many combination cough and cold medicines that contain several active ingredients.

This drug may counteract the blood pressure–lowering effects of amlodipine, which could lead to higher blood pressure and an increased heart rate. If you take amlodipine, check with your healthcare provider before taking pseudoephedrine or a medicine that contains pseudoephedrine.
7. General Anesthetics

General anesthesia is a type of medication given to prevent you from feeling pain during certain surgeries and procedures. General anesthetic medicines are given through a vein (intravenously) or as an inhaled gas.

Examples of these medicines are Amidate (etomidate) and Diprivan (propofol). When amlodipine is used with a general anesthetic, both drugs can increase the effects of the other on the heart and blood vessels, which can cause dangerously low blood pressure.

Before any surgery or procedure requiring anesthesia, review your current medication use with the anesthesiologist or your healthcare provider. They will need to adjust the doses of both drugs during your procedure to ensure your safety.
8. Oxymetazoline

Oxymetazoline is an ingredient found in OTC nasal decongestant sprays such as Afrin. This medicine may interfere with the blood pressure–lowering effects of amlodipine. If you take amlodipine, check with your healthcare provider before using oxymetazoline.
9. Sildenafil

Sildenafil, commonly known by the brand name Viagra, is an erectile dysfunction (ED) medication. It is also sold under the brand name Revation, which treats pulmonary arterial hypertension (high blood pressure in the arteries of the lungs).

Both sildenafil and amlodipine decrease blood pressure, so using them together could cause blood pressure to become too low. If your healthcare provider prescribes both together, they will monitor your blood pressure closely and possibly have you check your blood pressure at home.

This interaction can also occur with the ED drug Stendra (avanafil).
10. Simvastatin and Lovastatin

Certain statins (drugs used to treat high cholesterol), such as Zocor (simvastatin) and lovastatin, interact with amlodipine.

The interaction causes higher levels of the statin in the body, increasing the risk of severe side effects, including:

Myopathy (a condition that causes muscle weakness)
Rhabdomyolysis (a serious condition in which muscles break down, which can lead to kidney damage)

Healthcare providers usually avoid prescribing the combination. Instead, they might prescribe a different statin that is less likely to interact, such as Lipitor (atorvastatin), or use a lower statin dose.
11. Monoamine Oxidase Inhibitors (MAOIs)

MAOIs are an older class of drugs. An MAOI may be prescribed to treat depression but is not the first choice of treatment due to side effects, drug interactions, and dietary restrictions. Examples include Parnate (tranylcypromine) and Nardil (phenelzine). Some MAOIs, such as Azilect (rasagiline), can also be used to treat Parkinson’s disease. Parkinson’s is a neurological condition that affects muscle and motor function.

Typically, healthcare providers will avoid prescribing amlodipine with tranylcypromine because the combination could cause dangerously low blood pressure. And because tranylcypromine takes a long time to leave the body, this interaction can occur even for some time after you stop taking it.

Other MAOIs can also have the possible effect of dangerously lowering blood pressure. If your provider does prescribe amlodipine with an MAOI, close monitoring of your heart rate and blood pressure will be necessary.
12. Beta-Blockers

Many people need to take more than one blood pressure medication to effectively manage their blood pressure. However, when combining medications, you need to monitor your blood pressure to ensure it stays within a desired range and doesn’t become too low.

Beta-blockers (a class of drugs used to treat high blood pressure), such as Lopressor (metoprolol) or Tenormin (atenolol), can cause an additive effect with amlodipine. This, in turn, can cause low blood pressure and problems with the heart pumping blood effectively, especially in people with certain heart problems. You may be most at risk if you have any of the following:

Aortic stenosis (narrowing of the heart’s aortic valve)
Heart arrhythmia (abnormal heart rhythm)
Left ventricular dysfunction (weakness of the heart’s left ventricle)

Your healthcare provider will advise you on the appropriate treatment and necessary monitoring.
Summary

Amlodipine, commonly known as Norvasc, is a calcium channel blocker medication that is approved by the Food and Drug Administration (FDA) to treat high blood pressure, chest pain, and coronary artery disease. Various drugs, such as alprazolam, phenobarbital, certain antifungals, and certain antibiotics can interact with amlodipine.

Always ensure that your healthcare provider knows about all of your medications, including prescription and OTC drugs, vitamins, and dietary or herbal supplements. This will help your provider ensure the safest possible treatment for your condition.