Medically reviewed on December 12, 2017.
What is pentazocine?
Pentazocine is an opioid pain medication, sometimes called a narcotic.
Pentazocine is used to treat moderate to severe pain in adults and children who are at least 12 years old. It is also used as part of anesthesia for surgery.
Pentazocine may also be used for purposes not listed in this medication guide.
Pentazocine can slow or stop your breathing, and may be habit-forming. MISUSE OF THIS MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription.
Using this medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.
Fatal side effects can occur if you use this medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.
Before taking this medicine
You should not use pentazocine if you are allergic to it, or if you have:
You should not use pentazocine unless you are already using a similar opioid medicine and are tolerant to it. Opioid medicines include fentanyl, hydrocodone, morphine, oxycodone, and many others. Ask your doctor if you are not sure you are opioid-tolerant.
To make sure pentazocine is safe for you, tell your doctor if you have ever had:
any type of breathing problem or lung disease;
blockage in your digestive tract (stomach or intestines);
liver or kidney disease; or
problems with your gallbladder or adrenal gland.
Some medicines can interact with pentazocine and cause a serious condition called serotonin syndrome. Be sure your doctor knows if you also take stimulant medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. Ask your doctor before making any changes in how or when you take your medications.
If you use pentazocine 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 habit-forming medicine may need medical treatment for several weeks. Tell your doctor if you are pregnant or plan to become pregnant.
Pentazocine can pass into breast milk and may cause drowsiness, breathing problems, or withdrawal symptoms in the nursing baby. Tell your doctor if you are breast-feeding.
How is pentazocine given?
Follow all directions on your prescription label. Pentazocine can slow or stop your breathing. Never use pentazocine in larger amounts, or for longer than prescribed. Tell your doctor if the medicine seems to stop working as well in relieving your pain.
Pentazocine is injected under the skin or into a muscle, or into a vein through an IV. A healthcare provider will give you this injection.
You may be shown how to use an IV at home. Do not give yourself this medicine if you do not understand how to use the injection and properly dispose of needles, IV tubing, and other items used.
Pentazocine may be habit-forming, even at regular doses. Never share this medicine with another person, especially someone with a history of drug abuse or addiction. MISUSE OF NARCOTIC MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription. Selling or giving away pentazocine is against the law.
Pentazocine is usually given only for a short time.
Do not stop using pentazocine suddenly after long-term use, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using this medicine.
Use a disposable needle and syringe only once. Follow any state or local laws about throwing away used needles and syringes. Use a puncture-proof "sharps" disposal container (ask your pharmacist where to get one and how to throw it away). Keep this container out of the reach of children and pets.
Store at room temperature away from moisture and heat. Keep track of your medicine. Pentazocine is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.
Do not keep leftover opioid medication. Just one dose can cause death in someone using this medicine accidentally or improperly. Ask your pharmacist where to locate a drug take-back disposal program. If there is no take-back program, flush the unused medicine down the toilet.
What happens if I miss a dose?
Since pentazocine is used for pain, you are not likely to miss a dose. Skip any missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.
If pentazocine is given by a healthcare professional, you are not likely to miss a dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of pentazocine can be fatal.
What should I avoid while using pentazocine?
Do not drink alcohol. Dangerous side effects or death could occur.
Pentazocine may impair your thinking or reactions. Avoid driving or operating machinery until you know how this medicine will affect you. Dizziness or severe drowsiness can cause falls or other accidents.
Pentazocine side effects
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Like other narcotic medicines, pentazocine can slow your breathing. Death may occur if breathing becomes too weak. A person caring for you should 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;
a light-headed feeling, like you might pass out;
pain, burning, irritation, or skin changes where the injection was given; or
Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.
Serious side effects may be more likely in older adults and those who are overweight, malnourished, or debilitated.
Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.
Common side effects may include:
nausea, vomiting; or
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.
See also: Side effects (in more detail)
What other drugs will affect pentazocine?
Narcotic (opioid) medication can interact with many other drugs and cause dangerous side effects or death. Be sure your doctor knows if you also use:
other narcotic medications--opioid pain medicine or prescription cough medicine;
drugs that make you sleepy or slow your breathing--a sleeping pill, muscle relaxer, tranquilizer, antidepressant, or antipsychotic medicine.
This list is not complete. Other drugs may interact with pentazocine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Copyright 1996-2018 Cerner Multum, Inc. Version: 4.02.
More about pentazocine
- Pentazocine Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Interactions
- Support Group
- En Español
- 9 Reviews – Add your own review/rating
- Drug class: narcotic analgesics
Other brands: Talwin
- Pentazocine Hydrochloride (AHFS Monograph)
- Pentazocine Lactate (AHFS Monograph)
- Pentazocine (Wolters Kluwer)