Phenobarbital: Uses, Dosage, Side Effects, and Interactions

Summary of Key Points

Phenobarbital is primarily used to treat epilepsy and seizure disorders. It can also help manage anxiety, insomnia, and symptoms of alcohol withdrawal. As a barbiturate, it works by calming the brain and nervous system. Phenobarbital is available in various forms and strengths, with dosing tailored to the specific condition being treated. Always consult your healthcare provider before making any changes to your medication regimen.

Names of Medication

US Brand Name: Luminal

Generic Name: Phenobarbital

The generic name refers to the active ingredient, while the brand name is assigned by the manufacturer. In this article, the generic name is listed in parentheses.

Pharmacologic Category

Barbiturate

Anticonvulsant

Sedative-Hypnotic

Phenobarbital Dosage

Phenobarbital is prescribed for a variety of conditions, with dosage and frequency depending on the specific diagnosis. Always follow your healthcare provider’s instructions and consult them before adjusting your dose. You can also schedule a telemedicine appointment with one of our providers for personalized advice.

Phenobarbital for Epilepsy

Initial Dose: 60-100 mg once daily

Maintenance Dose: 60-200 mg once daily

Duration: Long-term treatment

Phenobarbital for Seizure Disorders

Initial Dose: 1-3 mg/kg/day, divided into 1-2 doses

Maintenance Dose: 60-200 mg/day

Duration: Long-term treatment

Phenobarbital for Insomnia

Initial Dose: 30-120 mg at bedtime

Duration: Short-term use (typically no longer than 2 weeks)

Phenobarbital for Anxiety Disorders

Initial Dose: 30-120 mg/day, divided into 1-2 doses

Duration: Short-term use

Phenobarbital for Alcohol Withdrawal Syndrome

Initial Dose: 30-120 mg every 6-8 hours

Duration: Short-term use (typically 1-2 weeks)

Phenobarbital for Sedation

Initial Dose: 30-120 mg/day, divided into 1-2 doses

Duration: Short-term use

Phenobarbital for Hyperbilirubinemia

Initial Dose: 5 mg/kg/day

Duration: Short-term use

Phenobarbital for Status Epilepticus

Initial Dose: 15-20 mg/kg IV (intravenous)

Duration: Emergency use

Phenobarbital for Tetanus

Initial Dose: 60-200 mg/day

Duration: Short-term use

Phenobarbital for Pain Management

Initial Dose: 30-120 mg/day, divided into 1-2 doses

Duration: Short-term use

Dosage Forms and Strengths

Tablets: 15 mg, 30 mg, 60 mg, 100 mg

Oral Solution: 20 mg/5 mL

Injection: 65 mg/mL, 130 mg/mL

Administration Instructions

Take Phenobarbital exactly as prescribed by your healthcare provider. It can be taken with or without food. If using the oral solution, measure the dose carefully with a special measuring device. Do not stop taking Phenobarbital suddenly without consulting your doctor, as this can cause withdrawal symptoms or worsen your condition. If you miss a dose, take it as soon as you remember unless it is close to your next scheduled dose.

Phenobarbital Side Effects and Adverse Reactions

Like all medications, Phenobarbital can cause side effects. Some are more common than others, and certain side effects may require immediate medical attention. If you experience any severe or unusual symptoms, contact your healthcare provider or seek medical help right away.

1. Drowsiness (Common): Feeling unusually sleepy or fatigued.
2. Dizziness (Common): A sensation of spinning or losing balance.
3. Headache (Common): Pain or discomfort in the head or neck area.
4. Confusion (Less Common): Difficulty thinking clearly or concentrating.
5. Depression (Less Common): Persistent feelings of sadness or hopelessness.
6. Respiratory Depression (Rare): Slow or shallow breathing, which can be life-threatening.
7. Allergic Reaction (Rare): Rash, itching, swelling, or difficulty breathing.

Contraindications

A contraindication is a specific situation or condition where a medication should not be used because it may be harmful. If you have any of the following conditions, you should not take Phenobarbital. Always consult your healthcare provider to discuss your medical history before starting any new medication.

1. Severe liver disease: Phenobarbital is processed by the liver, and if your liver is not functioning properly, the medication can accumulate in your body and cause serious side effects.
2. Severe respiratory conditions: Phenobarbital can slow down your breathing, so if you have a condition like chronic obstructive pulmonary disease (COPD) or sleep apnea, it may worsen your symptoms.
3. Porphyria: A rare genetic disorder affecting heme production. Phenobarbital can trigger a porphyria attack, which can be life-threatening.
4. Allergic reaction to barbiturates: If you have had a previous allergic reaction to Phenobarbital or other barbiturates, you should not take this medication, as it could cause a serious or life-threatening reaction.
5. History of addiction or substance abuse: Phenobarbital has the potential for abuse and dependence. If you have a history of substance use disorder, your doctor may recommend an alternative treatment.

Phenobarbital Drug Interactions

Phenobarbital can interact with other medications, increasing the risk of side effects or reducing the effectiveness of either drug. Inform your healthcare provider about all the medications you are currently taking, including over-the-counter drugs, supplements, and herbal products. Here are some common medications that may interact with Phenobarbital:

1. Warfarin (Coumadin): Phenobarbital can reduce the effectiveness of warfarin, increasing the risk of blood clots.
2. Oral contraceptives (birth control pills): Phenobarbital can make birth control pills less effective, increasing the risk of unintended pregnancy.
3. Phenytoin (Dilantin): Both drugs are used to treat seizures, but taking them together can alter their effectiveness and increase the risk of side effects.
4. Valproic acid (Depakote): This interaction can increase the risk of liver damage and other serious side effects.
5. Rifampin (Rifadin): This antibiotic can decrease the effectiveness of Phenobarbital, leading to inadequate seizure control.
6. Alcohol: Alcohol can enhance the sedative effects of Phenobarbital, leading to dangerous drowsiness, slowed breathing, or even coma.

Phenobarbital in Pregnancy

Is it safe to take Phenobarbital during pregnancy?

Phenobarbital is classified as a pregnancy category D medication, meaning there is evidence of potential risk to the fetus. However, in certain situations, the benefits of controlling seizures may outweigh these risks. Phenobarbital has been associated with birth defects, such as heart abnormalities and cleft palate, and may also affect brain development. If you are pregnant or planning to become pregnant, it’s essential to discuss your treatment options with your healthcare provider. They can help you carefully weigh the risks and benefits and may suggest alternative therapies if appropriate.

Phenobarbital while Breastfeeding

Is it safe to take Phenobarbital while breastfeeding?

Phenobarbital can pass into breast milk and may cause drowsiness, irritability, or feeding difficulties in a nursing infant. In some cases, it may also impact the baby’s development. If you are breastfeeding, it’s important to consult your healthcare provider to determine whether Phenobarbital is the best option for you. They may recommend monitoring your baby for any side effects or suggest an alternative medication.

Estimated Cost of Phenobarbital Medication

The cost of a 30-day supply of Phenobarbital without insurance can vary. However, with a GoodRx coupon, the price typically ranges from $10 to $20. Prices may differ depending on the pharmacy and dosage, so it’s a good idea to compare costs or use a discount card to find the best option.

Possible Alternatives to Phenobarbital

If Phenobarbital isn’t the right medication for you, there are other treatment options available. It’s important to discuss any changes to your treatment plan with your healthcare provider. You can also schedule a telemedicine appointment with one of our providers to explore these alternatives.

Epilepsy

Other anticonvulsants, such as levetiracetam (Keppra), lamotrigine (Lamictal), or valproic acid (Depakote), may be considered. Additionally, lifestyle modifications like managing stress, maintaining a regular sleep schedule, and avoiding known seizure triggers can also be beneficial.

Seizure Disorders

Medications like carbamazepine (Tegretol) or topiramate (Topamax) may be effective alternatives. In some cases, a ketogenic diet has been shown to help reduce the frequency of seizures.

Insomnia

Non-medication approaches, such as cognitive behavioral therapy for insomnia (CBT-I), relaxation techniques, and improving sleep hygiene, can be effective. Medications like zolpidem (Ambien) or melatonin may also be considered if necessary.

Anxiety Disorders

Selective serotonin reuptake inhibitors (SSRIs), such as sertraline (Zoloft), or cognitive behavioral therapy (CBT) are common alternatives. Mindfulness practices and regular physical activity may also help manage anxiety symptoms.

Alcohol Withdrawal Syndrome

Benzodiazepines, such as lorazepam (Ativan), are typically used to manage alcohol withdrawal. In some cases, gabapentin (Neurontin) may be considered as an alternative.

Sedation

Other sedatives, such as midazolam (Versed) or propofol, are often used in medical settings. For mild sedation, over-the-counter options like diphenhydramine (Benadryl) may be considered.

Hyperbilirubinemia

Phototherapy is the standard treatment for newborns with elevated bilirubin levels. In more severe cases, an exchange transfusion may be necessary.

Status Epilepticus

Benzodiazepines, such as diazepam (Valium) or lorazepam (Ativan), are commonly used to stop prolonged seizures.

Tetanus

Treatment for tetanus typically includes tetanus immune globulin, antibiotics, and muscle relaxants like diazepam (Valium).

Pain Management

Alternatives to Phenobarbital for pain management include non-opioid pain relievers like acetaminophen (Tylenol) or ibuprofen (Advil). For chronic pain, medications such as gabapentin (Neurontin) or physical therapy may be helpful.

Recent Updates on Phenobarbital Research

Recent studies have focused on the long-term effects of Phenobarbital, particularly in children with epilepsy. Research suggests that prolonged use of Phenobarbital in young children may affect cognitive development and behavior. As a result, healthcare providers are increasingly considering other anticonvulsants for pediatric patients. Additionally, ongoing research is exploring the use of Phenobarbital for neonatal seizures, with some studies indicating it may still be a valuable option in certain cases. However, newer medications with fewer side effects are being investigated as potential alternatives.

For the latest information on Phenobarbital and to discuss whether it’s the right treatment for you, schedule a telemedicine appointment with one of our providers today.

James Kingsley

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