Butorphanol is an opioid pain medication that is used to treat moderate to severe pain.

Butorphanol may also be used for purposes not listed in this medication guide.

You should not use butorphanol if you are allergic to it, or if you have:

• severe asthma or breathing problems; or
• a stomach or bowel obstruction (including paralytic ileus).

Tell your doctor if you have ever had:

• breathing problems, sleep apnea (breathing stops during sleep);
• liver or kidney disease;
• a head injury, brain tumor, or seizures;
• heart disease, high blood pressure, recent heart attack; or
• alcoholism or drug addiction.

If you use opioid medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on opioids may need medical treatment for several weeks.

Ask a doctor before using opioid medicine if you are breastfeeding. Tell your doctor if you notice severe drowsiness or slow breathing in the nursing baby.

Use Butorphanol (Stadol) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should give naloxone and/or seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Call your doctor at once if you have:

• noisy breathing, sighing, shallow breathing, breathing that stops;
• slow heart rate or weak pulse;
• fast or pounding heartbeats;
• problems with urination;
• tremors, numbness or tingling;
• confusion, feeling like you are floating;
• a light-headed feeling, like you might pass out;
• high levels of serotonin in the body--agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, diarrhea; or
• low cortisol levels--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

Serious breathing problems may be more likely in older adults and those who are debilitated or have wasting syndrome or chronic breathing disorders.

Common side effects include:

• drowsiness, dizziness;
• sleep problems (insomnia);
• nausea, vomiting; or
• stuffy nose.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Do not drink alcohol. Dangerous side effects or death could occur.

Avoid driving or hazardous activity until you know how this medicine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.