Nifedipine 20mg Capsules

Nifedipine is a dihydropyridine calcium channel blocker that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and myocardial cells. This leads to peripheral arterial vasodilation, reduced systemic vascular resistance, and decreased afterload, resulting in a reduction in blood pressure. It also dilates coronary arteries, increasing myocardial oxygen supply.

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
New or worsening chest pain
Abnormal heartbeat
Mood changes
Shortness of breath, significant weight gain, or swelling in the arms or legs
Muscle pain or cramping
Shakiness
Severe constipation or stomach pain, which may indicate a serious bowel problem
Black, tarry, or bloody stools
Vomiting blood or coffee ground-like material

Other Possible Side Effects

Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or persist, contact your doctor:

Dizziness, fatigue, or weakness
Headache
Flushing
Heartburn
Upset stomach
* Feeling nervous or excitable

Reporting Side Effects

This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before taking this medication, it is essential to inform your doctor about the following:

Any allergies you have, including allergies to this drug, its components, or other substances, such as foods or medications. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have recently had a heart attack.
Any medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial because certain medications, such as those used to treat HIV, infections, seizures, and other conditions, should not be taken with this drug. There are many potential interactions, so it is vital to disclose all medications to avoid adverse reactions.
It is important to note that this is not an exhaustive list of all medications or health conditions that may interact with this drug.

To ensure your safety, it is crucial to inform your doctor and pharmacist about all your medications, including prescription and OTC drugs, natural products, and vitamins, as well as any health problems you have. This will enable them to verify that it is safe for you to take this medication in conjunction with your other medications and health conditions. Never start, stop, or modify the dosage of any medication without first consulting your doctor.

Important Warnings and Precautions

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

Caution with Daily Activities
Until you know how this medication affects you, avoid driving and other activities that require alertness. To minimize the risk of dizziness or fainting, rise slowly from a sitting or lying position, and be cautious when climbing stairs.

Cardiovascular Risks
Although rare, new or worsening chest pain can occur after starting this medication or increasing the dose. In some cases, this may lead to a heart attack. Individuals with severe heart blood vessel disease may be at higher risk. Discuss these risks with your doctor.

Monitoring and Follow-Up
Regularly check your blood pressure as directed by your healthcare provider. Additionally, have blood work done as instructed by your doctor and discuss the results with them.

Dietary Interactions
Avoid consuming grapefruit and grapefruit juice while taking this medication.

Interactions with Other Medications
If you have high blood pressure, consult your doctor before using over-the-counter (OTC) products that may increase blood pressure, such as:
- Cough or cold medications
- Diet pills
- Stimulants
- Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen
- Certain natural products or aids

Gastrointestinal Risks
A long-acting form of this medication has been associated with severe stomach and bowel problems, including blockage and ulcers, which may require hospitalization. Discuss these risks with your doctor.

Unapproved Use
This form of the medication is not approved for treating high blood pressure. Using it to rapidly lower high blood pressure can lead to severe hypotension, heart attack, and death. However, your doctor may determine that the benefits of taking this medication outweigh the risks. If you are taking this medication for high blood pressure, discuss the benefits and risks with your doctor.

Special Precautions
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.

Pregnancy and Breastfeeding
Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. You and your doctor will need to discuss the benefits and risks of taking this medication to you and your baby.

• Strong CYP3A4 inducers (e.g., rifampin, St. John's Wort) - significantly reduces nifedipine levels.
• Grapefruit juice (large amounts) - significantly increases nifedipine levels.

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, erythromycin, ritonavir, saquinavir, telithromycin, nefazodone) - can significantly increase nifedipine levels, leading to hypotension.
• Beta-blockers - additive hypotensive effects, potential for excessive bradycardia/heart block (monitor closely if co-administered).
• Digoxin - increased digoxin levels.
• Quinidine - decreased quinidine levels.
• Fentanyl - severe hypotension.
• Tacrolimus - increased tacrolimus levels.

• Cimetidine, Ranitidine - increased nifedipine levels.
• Theophylline - increased theophylline levels.
• Magnesium sulfate - increased neuromuscular blockade.
• Phenytoin, Valproic acid - altered nifedipine levels.
• Cisapride - increased nifedipine levels.

• Dizziness
• Lightheadedness
• Headache
• Flushing
• Palpitations
• Peripheral edema (swelling of ankles/feet)
• Worsening chest pain
• Shortness of breath

Nifedipine is Pregnancy Category C. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. It has been used off-label for preterm labor, but its role in chronic hypertension during pregnancy requires careful consideration.

Nifedipine is excreted in breast milk in small amounts. Generally considered compatible with breastfeeding (L3 - Moderately Safe), but monitor the infant for potential adverse effects.

Safety and efficacy have not been established in pediatric patients for hypertension or angina. Use is generally not recommended for routine management, but may be used off-label in specific situations under expert supervision.

Geriatric patients may be more sensitive to the hypotensive effects of nifedipine. Start with lower doses and titrate slowly. Increased incidence of peripheral edema may occur.

• Immediate-release (IR) nifedipine can cause rapid and significant drops in blood pressure, leading to reflex tachycardia and is generally not preferred for acute hypertensive emergencies due to unpredictable effects and increased risk of adverse events (e.g., myocardial ischemia, stroke).
• Extended-release (ER) formulations of nifedipine are preferred for chronic management of hypertension and angina due to smoother blood pressure control and fewer side effects.
• Patients should be advised to avoid grapefruit juice due to potential for increased nifedipine levels and adverse effects.
• Peripheral edema (swelling of ankles/feet) is a common dose-dependent side effect, especially with higher doses of nifedipine.
• Nifedipine IR capsules should be swallowed whole and not chewed, crushed, or broken.

• Other Dihydropyridine Calcium Channel Blockers (e.g., Amlodipine, Felodipine, Nicardipine)
• Non-Dihydropyridine Calcium Channel Blockers (e.g., Diltiazem, Verapamil)
• ACE Inhibitors (e.g., Lisinopril, Enalapril)
• Angiotensin Receptor Blockers (ARBs) (e.g., Valsartan, Losartan)
• Beta-blockers (e.g., Metoprolol, Atenolol)
• Thiazide Diuretics (e.g., Hydrochlorothiazide)
• Alpha-blockers (e.g., Prazosin, Doxazosin)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.