Carbamazepine 300mg ER Capsules

Carbamazepine stabilizes the inactivated state of voltage-gated sodium channels, thereby inhibiting repetitive firing of action potentials in depolarized neurons. This reduces the propagation of abnormal electrical impulses in the brain, leading to its anticonvulsant and antineuralgic effects. It may also have effects on calcium channels, potassium channels, and neurotransmitter systems (e.g., adenosine, GABA).

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 immediately or seek emergency medical attention:

Signs of an allergic reaction, such as:
+ Rash or hives
+ Itching or red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing or tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of low sodium levels, including:
+ Headache
+ Difficulty focusing or memory problems
+ Feeling confused or weak
+ Seizures or changes in balance
Changes in speech or vision
Hallucinations (seeing or hearing things that are not there)
Difficulty walking
A severe and potentially life-threatening condition, known as a hypersensitivity reaction, has occurred in people taking seizure medications like this one. Seek medical help right away if you experience:
+ Swollen glands
+ Fever
+ Rash
+ Painful sores in the mouth or around the eyes
+ Chest pain
+ Signs of kidney problems, such as:
- Inability to pass urine
- Changes in the amount of urine passed
+ Signs of liver problems, including:
- Dark urine
- Tiredness
- Decreased appetite
- Upset stomach or stomach pain
- Light-colored stools
- Vomiting
- Yellow skin or eyes
Neuroleptic malignant syndrome (NMS), a rare but potentially life-threatening condition, may occur. Seek medical help right away if you experience:
+ Fever
+ Muscle cramps or stiffness
+ Dizziness
+ Severe headache
+ Confusion or changes in thinking
+ Fast heartbeat or irregular heartbeat
+ Excessive sweating

Other Possible Side Effects

Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. If you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical help if they bother you or do not go away:

Feeling dizzy, sleepy, tired, or weak
Upset stomach or vomiting
Dry mouth
* Constipation

Reporting Side Effects

This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, contact 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: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have kidney disease, as this may affect how your body processes the medication.
A history of certain health conditions, such as bone marrow problems or porphyria, which may impact your ability to take this medication safely.
Any medications you are currently taking, including prescription and over-the-counter drugs, natural products, and vitamins. This is crucial because some medications, such as those used to treat hepatitis C, HIV, infections, and other conditions, may interact with this medication and should not be taken together.
* If you have taken specific medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of very high blood pressure.

To ensure your safety, it is vital to provide your doctor and pharmacist with a comprehensive list of all your medications, health problems, and allergies. This will help them determine whether it is safe for you to take this medication and identify any potential interactions or concerns. Never start, stop, or change the dose of any medication without first consulting your doctor.

Important Warnings and Cautions

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. This will help ensure your safety and prevent any potential interactions with other treatments.

Caution with Daily Activities

Until you know how this medication affects you, avoid driving and engaging in activities that require alertness. This will help prevent accidents and ensure your safety.

Monitoring and Follow-up

Your doctor will schedule regular blood tests to monitor your condition. Be sure to keep these appointments and follow your doctor's instructions. Additionally, have an eye exam as recommended by your doctor to check for any potential changes in your vision.

Interference with Lab Tests

This medication may affect the results of certain lab tests. Inform all your healthcare providers and lab personnel that you are taking this medication to ensure accurate test results.

Pregnancy Tests and Contraception

This medication may cause false results in some pregnancy tests. If you are pregnant or think you may be pregnant, consult your doctor. Furthermore, if you are using birth control pills or other hormone-based contraception, you may need to use an additional form of birth control, such as a condom, as this medication may reduce the effectiveness of your current contraception.

Interactions with Other Substances

Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may cause drowsiness, consult your doctor. Additionally, if you regularly drink grapefruit juice or eat grapefruit, discuss this with your doctor, as it may interact with your medication.

Stopping the Medication

Do not stop taking this medication abruptly without consulting your doctor, as this may increase your risk of seizures. If you need to stop taking this medication, your doctor will instruct you on how to gradually taper off the dosage.

Seizure Management

If you experience changes in your seizure pattern or severity after starting this medication, consult your doctor. Like other seizure medications, this medication may rarely increase the risk of suicidal thoughts or behaviors, particularly in individuals with a history of suicidal ideation. Monitor your mood and behavior, and immediately report any new or worsening symptoms, such as depression, anxiety, or mood changes, to your doctor.

Cardiovascular Risks

This medication may increase the risk of heart problems, including heart failure and abnormal heart rhythms, which can be fatal. Seek immediate medical attention if you experience a rapid, slow, or irregular heartbeat, severe dizziness, fainting, shortness of breath, significant weight gain, or swelling in your arms or legs.

Rare but Serious Reactions

In rare cases, this medication may cause a severe reaction called angioedema, which can be life-threatening. Symptoms include swelling of the hands, face, lips, eyes, tongue, or throat, difficulty breathing, swallowing, or speaking, and unusual hoarseness. If you experience any of these symptoms, seek medical help immediately.

Special Considerations

If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects. Additionally, this medication may affect fertility in men, so discuss this with your doctor if you are trying to conceive.

Pregnancy and Breastfeeding

If you are pregnant or become pregnant while taking this medication, consult your doctor immediately, as it may harm the unborn baby. If you are breastfeeding, discuss the potential risks to your baby with your doctor.

• MAO inhibitors (within 14 days of use)
• Nefazodone
• Delavirdine
• Boceprevir
• Telaprevir
• Voriconazole
• Other strong CYP3A4 inhibitors (e.g., some azole antifungals, macrolide antibiotics) if co-administration cannot be avoided and close monitoring is not feasible.

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, erythromycin, grapefruit juice) - increase carbamazepine levels.
• Strong CYP3A4 inducers (e.g., phenytoin, phenobarbital, rifampin) - decrease carbamazepine levels.
• Oral contraceptives - decreased efficacy of contraceptives.
• Warfarin - decreased anticoagulant effect.
• Lamotrigine, Valproic acid - altered levels of both drugs, increased risk of toxicity.
• Cyclosporine, Tacrolimus, Sirolimus, Everolimus - decreased immunosuppressant levels.
• Lurasidone, Quetiapine, Aripiprazole, Olanzapine - decreased antipsychotic levels.
• Doxycycline - decreased doxycycline levels.
• Theophylline - decreased theophylline levels.
• Corticosteroids - decreased corticosteroid levels.
• Calcium channel blockers (e.g., felodipine, nifedipine, verapamil, diltiazem) - altered levels of both drugs.
• Benzodiazepines (e.g., alprazolam, midazolam) - decreased benzodiazepine levels.
• Tricyclic antidepressants (e.g., imipramine, amitriptyline) - altered levels of both drugs, increased risk of toxicity.

• Acetaminophen - increased risk of hepatotoxicity with chronic carbamazepine use.
• Bupropion - decreased bupropion levels, increased risk of seizures.
• Clozapine - increased risk of bone marrow suppression.
• Lithium - increased risk of neurotoxicity.
• Diuretics (e.g., hydrochlorothiazide, furosemide) - increased risk of hyponatremia.
• St. John's Wort - decreased carbamazepine levels.
• Grapefruit juice - increased carbamazepine levels (avoid or limit).

• Alcohol - increased CNS depression.
• Other CNS depressants - additive CNS depression.

• Skin rash, blistering, peeling (signs of SJS/TEN)
• Fever, sore throat, mouth sores, easy bruising, petechiae, unusual bleeding (signs of hematologic abnormalities)
• Yellowing of skin or eyes (jaundice), dark urine, abdominal pain, nausea, vomiting (signs of liver dysfunction)
• Dizziness, drowsiness, ataxia, blurred vision, diplopia (common CNS side effects, may indicate toxicity)
• Confusion, lethargy, headache, seizures (signs of severe hyponatremia)
• Swelling of face, lips, tongue, or throat (angioedema)
• Shortness of breath, wheezing (hypersensitivity reaction)

Carbamazepine is associated with an increased risk of major congenital malformations, particularly neural tube defects (e.g., spina bifida), craniofacial defects (e.g., cleft lip/palate), and developmental delays. It should only be used during pregnancy if the potential benefit outweighs the significant risks. Folic acid supplementation (at least 4 mg/day) is recommended for women of childbearing potential and during pregnancy.

Carbamazepine is excreted into breast milk. While the amount transferred is relatively low, infants should be monitored for adverse effects such as drowsiness, poor feeding, weight gain, and signs of liver dysfunction or blood dyscrasias. Breastfeeding may be considered with careful monitoring of the infant.

Carbatrol ER capsules are approved for epilepsy in children >10 years of age. Dosing must be carefully titrated. Children may be more susceptible to certain side effects. Monitoring of drug levels and adverse effects is crucial.

Elderly patients may be more susceptible to adverse effects, particularly hyponatremia, dizziness, ataxia, and confusion. Start with lower doses and titrate slowly. Close monitoring of serum sodium, renal function, and CNS side effects is recommended.

• Carbamazepine is a potent autoinducer of its own metabolism, meaning its half-life shortens over time, requiring dose adjustments after initiation to achieve stable therapeutic levels (typically 2-4 weeks).
• Always screen patients of Asian ancestry for the HLA-B*1502 allele before initiating carbamazepine due to the significantly increased risk of SJS/TEN.
• Monitor CBC and LFTs regularly, especially during the first few months of therapy, due to the black box warnings for aplastic anemia, agranulocytosis, and liver failure.
• Hyponatremia is a common side effect, especially in elderly patients or those on diuretics; monitor serum sodium levels.
• Counsel patients to report any rash, fever, sore throat, mouth sores, or unusual bruising/bleeding immediately.
• Grapefruit juice significantly increases carbamazepine levels; advise patients to avoid it.
• Carbamazepine can decrease the effectiveness of hormonal contraceptives; advise women of childbearing potential to use alternative or additional birth control methods.

• Other antiepileptic drugs (e.g., valproic acid, lamotrigine, levetiracetam, oxcarbazepine, phenytoin, topiramate, gabapentin, pregabalin)
• For trigeminal neuralgia: oxcarbazepine, gabapentin, pregabalin, baclofen, lamotrigine, phenytoin, surgical interventions (e.g., microvascular decompression, gamma knife radiosurgery)

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others or take someone else's medication. This medication is accompanied by a Medication Guide, a patient fact sheet that provides crucial information. Please read this guide carefully and review it again whenever you receive a refill of this medication. If you have any questions or concerns about this medication, consult your doctor, 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 reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.