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Overview: Butalbital/acetaminophen is used for tension headaches. It slows down your nervous system and blocks pain signals to help with tension headaches. Common side effects include dizziness and drowsiness. Do not drive or do other activities that require alertness or coordination until you know how this medicine affects you.

Uses

What is butalbital/acetaminophen used for?

Butalbital/acetaminophen is commonly used to help relieve tension headaches, which can be caused by tight or tense muscles.

Butalbital/acetaminophen may also be used for other conditions as determined by your health care provider.

How does butalbital/acetaminophen work (mechanism of action)?

Butalbital and acetaminophen work in different ways to relieve a tension headache. Butalbital is a barbiturate, which works by slowing down your brain and nervous system. Acetaminophen may work by blocking pain signals.

How is butalbital/acetaminophen supplied (dosage forms)?

Brand and other names

  • Allzital

Dosage forms and strengths

  • 50 mg/300 mg oral capsules
  • 25 mg/325 mg oral tablets
  • 50 mg/325 mg oral tablets
  • 50 mg/300 mg oral tablets

How should I store butalbital/acetaminophen?

Butalbital/acetaminophen should be stored at room temperature, between 68 F and 77 F (20 C and 25 C). It can be exposed to temperatures between 59 F and 86 F (15 C and 30 C) for shorter periods of time, such as when transporting it. Store it in a cool, dry place.

Side Effects

What are the most common side effects of butalbital/acetaminophen?

The most common side effects of butalbital/acetaminophen are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Drowsiness
  • Dizziness or lightheadedness
  • Shortness of breath
  • Nausea or vomiting
  • Stomach pain
  • Intoxicated feeling

There may be other side effects of butalbital/acetaminophen that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of butalbital/acetaminophen?

While less common, the most serious side effects of butalbital/acetaminophen are described below, along with what to do if they happen.

Severe Allergic Reactions. Butalbital/acetaminophen may cause allergic reactions, which can be serious. Stop taking butalbital/acetaminophen and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Liver Damage. Liver damage, also called hepatotoxicity, can happen when you take butalbital/acetaminophen. Call your health care provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Severe Skin Reactions. Butalbital/acetaminophen can cause severe skin reactions called acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN) that can lead to death if not treated. If you get a rash, stop taking butalbital/acetaminophen and call your health care provider right away. Get emergency help if you have any of the following symptoms of a severe skin reaction.

  • Painful red or purple skin that looks burned and peels off
  • Flat red rash or blisters on your skin, mouth, nose, and genitals
  • Red, painful, watery eyes

Risk of Misuse and Addiction. Misusing butalbital/acetaminophen can lead to serious side effects like coma or death. Misuse means taking a medicine in a way other than how it was prescribed. Take butalbital/acetaminophen exactly as prescribed. Tell your health care provider if you feel that butalbital/acetaminophen is not working. Call your health care provider right away or go to the nearest emergency room if you have any of the following serious symptoms.

  • Sudden confusion or feeling disoriented
  • Feeling paranoid
  • Suicidal thoughts or actions
  • Seizures
  • Trouble breathing

Warnings & Precautions

Who should not use butalbital/acetaminophen?

Allergies to Ingredients. People who are allergic to any of the following should not take butalbital/acetaminophen.

  • Butalbital
  • Acetaminophen 
  • Allzital 
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific butalbital/acetaminophen products they stock.

Porphyria. Butalbital/acetaminophen should not be used if you have porphyria, which is a rare disorder that affects the body’s ability to make a substance called heme. Heme is important for carrying oxygen in the blood. When the body cannot make heme properly, certain chemicals build up and cause nerve or skin problems. 

What should I know about butalbital/acetaminophen before using it?

Do not take butalbital/acetaminophen unless it has been prescribed to you by a health care provider. Take it as prescribed.

Do not share butalbital/acetaminophen with other people, even if they have the same condition as you. It may harm them.

Keep butalbital/acetaminophen out of the reach of children. Butalbital/acetaminophen is a controlled substance because it can be misused or lead to dependence. Store it in a safe place to protect it from theft. It is illegal to sell or give away this medicine.

If you have taken butalbital/acetaminophen on a regular basis, do not stop taking the medicine without talking to your health care provider. Stopping too quickly can cause serious side effects. Call your health care provider right away if you have any of the following symptoms.

  • Crankiness
  • High or low energy or low mood
  • Feeling restless 
  • Changes in sleep habits
  • Headache
  • Nausea
  • Dizziness
  • Electric shock-like feelings
  • Confusion

Butalbital/acetaminophen can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how butalbital/acetaminophen affects you.

Do not take more than 4,000 mg of acetaminophen per day. Taking too much acetaminophen can cause serious liver problems that could lead to death. Talk to your pharmacist about what medicines contain acetaminophen. It can be found in Tylenol, some cough and cold medicines, some sleep medicines, and others. If you take too much acetaminophen, get emergency help right away, even if you do not feel sick.

People who are 65 years and older can be at greater risk of some side effects from butalbital/acetaminophen. Talk to your health care provider about your risks if you are in this age group.

What should I tell my health care provider before using butalbital/acetaminophen?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if butalbital/acetaminophen is right for you.

In particular, make sure that you discuss any of the following.

Alcohol Use Disorder or Substance Use Disorder. Talk to your health care provider if you use or used to use street drugs, have or had a problem using alcohol or prescription medicines, or live with someone with this problem. 

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Kidney problems 
  • Liver problems
  • Stomach problems

Other Medicines and Supplements. Butalbital/acetaminophen may interact with other medicines and supplements. Before taking butalbital/acetaminophen, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how butalbital/acetaminophen could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. If you take butalbital/acetaminophen on a regular basis during pregnancy, your baby may have withdrawal symptoms. Tell your health care provider if you took butalbital/acetaminophen during your pregnancy, especially near the end of your pregnancy.

Breastfeeding. Butalbital/acetaminophen passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should stop breastfeeding or stop taking butalbital/acetaminophen.

Interactions

Does butalbital/acetaminophen interact with foods or drinks?

There are no known interactions between butalbital/acetaminophen and foods or drinks.

Do not drink alcohol or use prescription or over-the-counter medicines that contain alcohol while taking butalbital/acetaminophen. Drinking alcohol while taking butalbital/acetaminophen can increase your risk of overdose and death.

Does butalbital/acetaminophen interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking butalbital/acetaminophen.

  • A monoamine oxidase inhibitor (MAOI), which is a medicine usually used for depression or Parkinson’s disease
  • An opioid, such as codeine, fentanyl, morphine, or oxycodone, which is a medicine used for certain types of pain
  • Chlordiazepoxide (Librium), which is a medicine used for anxiety 
  • Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, and medicines for anxiety

This may not be a complete list of medicines that can interact with butalbital/acetaminophen. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much butalbital/acetaminophen?

If you or someone else has used too much butalbital/acetaminophen, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of butalbital/acetaminophen?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses. Do not take more than your prescribed dose.