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Generic Name: butalbital/acetaminophen (bue-TAL-bi-tal/a-SEET-a-MIN-oh-fen)
Brand Name: Examples include Axocet and Phrenilin
Phrenilin contains acetaminophen. Severe and sometimes fatal liver problems, including the need for liver transplant, have been reported with the use of acetaminophen. Most cases of these liver problems occurred in patients taking excessive doses of acetaminophen (more than 4,000 mg per day). Also, patients who developed these liver problems were often using more than 1 medicine that contained acetaminophen. Discuss any questions or concerns with your doctor.
Phrenilin is used for:
Relieving tension headaches. It may also be used for other conditions as determined by your doctor.
How these medicines work is not completely understood. Acetaminophen works in the brain to relieve pain. Butalbital has a depressant effect that reduces anxiety and causes relaxation.
Do NOT use Phrenilin if:
- you are allergic to any ingredient in Phrenilin
- you have the blood disease porphyria
- you are taking sodium oxybate (GHB)
Contact your doctor or health care provider right away if any of these apply to you.
Before using Phrenilin:
Some medical conditions may interact with Phrenilin. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have a history of liver problems, kidney problems, heart problems, glucose-6-phosphate dehydrogenase (G6PD) deficiency, or lung or breathing problems
- if you are in very poor health or you have stomach pain
- if you drink alcohol; have a history of drug or alcohol abuse or dependence, mood or mental problems (eg, anxiety, depression), or suicidal thoughts or behaviors; or are going through withdrawal from alcohol or other substances
- if you have recently had surgery
Some MEDICINES MAY INTERACT with Phrenilin. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Anticoagulants (eg, warfarin) because the risk of bleeding may be increased or their effectiveness may be decreased by Phrenilin
- Monoamine oxidase inhibitors (MAOIs) (eg, phenelzine), narcotic analgesics (eg, morphine), sleeping medicines (eg, temazepam), or sodium oxybate (GHB) because they may increase the risk of Phrenilin's side effects
- Chlordiazepoxide, other narcotic analgesics (eg, morphine), or sleep medicines (eg, zolpidem) because the risk of their side effects may be increased by Phrenilin
- Clozapine, corticosteroids (eg, prednisone), doxycycline, estrogens (eg, estradiol, certain birth control pills), griseofulvin, metronidazole, quinidine, tacrolimus, teniposide, or theophylline because their effectiveness may be decreased by Phrenilin
- Medicines that may harm the liver (eg, methotrexate, isoniazid, certain medicines for HIV infection) because the risk of liver side effects may be increased. Ask your doctor if you are unsure if any of your medicines might harm the liver
This may not be a complete list of all interactions that may occur. Ask your health care provider if Phrenilin may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use Phrenilin:
Use Phrenilin as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Take Phrenilin by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation.
- Phrenilin is usually taken as needed. If you forget to take a dose of Phrenilin and you still have pain, take it when you remember as directed by your doctor. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use Phrenilin.
Important safety information:
- Phrenilin may cause drowsiness, dizziness, or light-headedness. These effects may be worse if you take it with alcohol or certain medicines. Use Phrenilin with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
- Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Phrenilin; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
- Do NOT take more than the recommended dose, take more often than prescribed, or use for longer than prescribed without checking with your doctor.
- Pain medications work best if they are used as the first signs of pain (or tension headache) occur. If you wait until the pain has significantly worsened, the pain medicine may not work as well.
- Phrenilin has acetaminophen in it. Before you start any new medicine, check the label to see if it has acetaminophen in it too. If it does or if you are not sure, check with your doctor or pharmacist.
- Phrenilin may harm your liver. Your risk may be greater if you drink alcohol while you are using Phrenilin. Talk to your doctor before you take Phrenilin or other pain relievers/fever reducers if you drink alcohol.
- A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.
- Contact your doctor right away if you take more than 4,000 mg of acetaminophen per day, even if you feel well.
- Tell your doctor or dentist that you take Phrenilin before you receive any medical or dental care, emergency care, or surgery.
- Hormonal birth control (eg, birth control pills) may not work as well while you are using Phrenilin. To prevent pregnancy, use an extra form of birth control (eg, condoms).
- Phrenilin may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Phrenilin.
- Use Phrenilin with caution in the ELDERLY; they may be more sensitive to its effects.
- Phrenilin should be used with extreme caution in CHILDREN younger than 12 years old; safety and effectiveness in these children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Phrenilin while you are pregnant. Phrenilin is found in breast milk. Do not breast-feed while taking Phrenilin.
When used for long periods of time or at high doses, Phrenilin may not work as well and may require higher doses to obtain the same effect as when originally taken. This is known as TOLERANCE. Talk with your doctor if Phrenilin stops working well. Do not take more than prescribed.
Some people who use Phrenilin for a long time may develop a need to continue taking it. People who take high doses are also at risk. This is known as DEPENDENCE or addiction. If you stop taking Phrenilin suddenly, you may have WITHDRAWAL symptoms. These may include anxiety, muscle twitching, trembling hands and fingers, weakness, dizziness, hallucinations, nausea, vomiting, sleeplessness, light-headedness, or seizures.
Possible side effects of Phrenilin:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Dizziness; drowsiness; light-headedness; mild stomach pain; nausea; vomiting.
Severe allergic reactions (rash; hives; itching; difficulty breathing or swallowing; tightness in the chest; swelling of the mouth, face, lips, throat, or tongue); confusion; fainting; fast heartbeat; fever, chills, or persistent sore throat; intoxicated feeling; mental or mood changes; numbness or tingling; red, swollen, blistered, or peeling skin; seizures; severe or persistent drowsiness; shortness of breath; sluggishness; symptoms of liver problems (eg, dark urine, loss of appetite, pale stools, severe stomach pain; yellowing of the skin or eyes); unusual bruising or bleeding; unusual tiredness or weakness.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center (http://www.aapcc.org ), or emergency room immediately. Symptoms may include cold or clammy skin; confusion; decreased urination; fainting; loss of consciousness; severe dizziness, drowsiness, or light-headedness; severe or persistent nausea or vomiting; slow, shallow, or abnormal breathing; symptoms of liver problems (eg, dark urine, loss of appetite, pale stools, severe stomach pain, yellowing of the skin or eyes); unusual bruising or bleeding; unusual sweating; unusual tiredness.Proper storage of Phrenilin:
Store Phrenilin at room temperature, between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Phrenilin out of the reach of children and away from pets.
- If you have any questions about Phrenilin, please talk with your doctor, pharmacist, or other health care provider.
- Phrenilin is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information should not be used to decide whether or not to take Phrenilin or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Phrenilin. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Phrenilin. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using Phrenilin.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.