Pentazocine may be habit forming, especially with prolonged use. Take pentazocine exactly as directed. Do not take more of it, take it more often, or take it in a different way than directed by your doctor. While you are taking pentazocine, discuss with your health care provider your pain treatment goals, length of treatment, and other ways to manage your pain. Tell your doctor if you or anyone in your family drinks or has ever drunk large amounts of alcohol, uses or has ever used street drugs, or has overused prescription medications, or has had an overdose, or if you have or have ever had depression or another mental illness. There is a greater risk that you will overuse pentazocine if you have or have ever had any of these conditions. Talk to your health care provider immediately and ask for guidance if you think that you have an opioid addiction or call the U.S. Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-HELP.
Pentazocine may cause serious or life-threatening breathing problems, especially during the first 24 to 72 hours of your treatment and any time your dose is increased. Your doctor will monitor you carefully during your treatment. Tell your doctor if you have or have ever had slowed breathing or asthma. Your doctor will probably tell you not to take pentazocine. Also tell your doctor if you have or have ever had lung disease such as chronic obstructive pulmonary disease (COPD; a group of diseases that affect the lungs and airways), a head injury, a brain tumor, or any condition that increases the amount of pressure in your brain. The risk that you will develop breathing problems may be higher if you are an older adult or are weak or malnourished due to disease. If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment: slowed breathing, long pauses between breaths, or shortness of breath.
Taking certain medications other medications with pentazocine may increase the risk that you will develop serious or life-threatening breathing problems, sedation, or coma. Tell your doctor and pharmacist if you are taking or plan to take any of the following medications: certain antifungal medications including itraconazole (Onmel, Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend); benzodiazepines such as alprazolam (Xanax), chlordiazepoxide (Librium), clonazepam (Klonopin), diazepam (Diastat, Valium), estazolam, flurazepam, lorazepam (Ativan), oxazepam, temazepam (Restoril), and triazolam (Halcion); carbamazepine (Carbatrol, Epitol, Tegretol, Teril); clarithromycin (Biaxin, in PrevPac); erythromycin (Erytab, Erythrocin);certain medications for human immunodeficiency virus (HIV) including indinavir (Crixivan), nelfinavir (Viracept), and ritonavir (Norvir, in Kaletra); medications for mental illness, nausea, or pain; muscle relaxants; phenytoin (Dilantin, Phenytek); rifampin (Rifadin, Rimactane, in Rifamate); sedatives; sleeping pills; or tranquilizers. Your doctor may need to change the doses of your medication and will monitor you carefully. If you take pentazocine with any of these medications and you develop any of the following symptoms, call your doctor immediately or seek emergency medical care: unusual dizziness, lightheadedness, extreme sleepiness, slowed or difficult breathing, or unresponsiveness. Be sure that your caregiver or family members know which symptoms may be serious so they can call the doctor or emergency medical care if you are unable to seek treatment on your own.
Drinking alcohol, taking prescription or nonprescription medications that contain alcohol, or using street drugs during your treatment with pentazocine increases the risk that you will experience these serious, life-threatening side effects. Do not drink alcohol, take prescription or nonprescription medications that contain alcohol, or use street drugs during your treatment.
Do not allow anyone else to take your medication. Pentazocine may harm or cause death to other people who take your medication, especially children.
Tell your doctor if you are pregnant or plan to become pregnant. If you take pentazocine regularly during your pregnancy, your baby may experience life-threatening withdrawal symptoms after birth. Tell your baby's doctor right away if your baby experiences any of the following symptoms: irritability, hyperactivity, abnormal sleep, high-pitched cry, uncontrollable shaking of a part of the body, vomiting, diarrhea, or failure to gain weight.
Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin your treatment with pentazocine and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website ( http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm ) or the manufacturer's website to obtain the Medication Guide.
Talk to your doctor about the risks of taking pentazocine.
IMPORTANT NOTICE
FDA Drug Safety Communication:
[Posted 4/13/2023]
- As part of its ongoing efforts to address the nation's opioid crisis, FDA is requiring several updates to the prescribing information of opioid pain medicines. The changes are being made to provide additional guidance for safe use of these drugs while also recognizing the important benefits when used appropriately. The changes apply to both immediate-release (IR) and extended-release/long-acting preparations (ER/LA).
- Updates to the IR opioids state that these drugs should not be used for an extended period unless the pain remains severe enough to require an opioid pain medicine and alternative treatment options are insufficient, and that many acute pain conditions treated in the outpatient setting require no more than a few days of an opioid pain medicine.
- Updates to the ER/LA opioids recommend that these drugs be reserved for severe and persistent pain requiring an extended period of treatment with a daily opioid pain medicine and for which alternative treatment options are inadequate.
- A new warning is being added about opioid-induced hyperalgesia (OIH) for both IR and ER/LA opioid pain medicines. This includes information describing the symptoms that differentiate OIH from opioid tolerance and withdrawal.
- Information in the boxed warning for all IR and ER/LA opioid pain medicines will be updated and reordered to elevate the importance of warnings concerning life-threatening respiratory depression, and risks associated with using opioid pain medicines in conjunction with benzodiazepines or other medicines that depress the central nervous system (CNS).
- Other changes will also be required in various other sections of the prescribing information to educate clinicians, patients, and caregivers about the risks of these drugs.
Why is this medicine prescribed?
Pentazocine is used to relieve moderate to severe pain. Pentazocine is in a class of medications called opiate (narcotic) analgesics. It works by changing the way the brain and nervous system respond to pain.
Are there other uses for this medicine?
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
How should this medicine be used?
Pentazocine comes as a tablet to take by mouth. It usually is taken every 3 to 4 hours as needed. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take pentazocine exactly as directed.
Pentazocine tablets should be taken by mouth. Do not try to dissolve and inject the tablets. Injecting pentazocine may cause serious health problems or death. Naloxone is added to the tablets so that people who inject dissolved tablets will not experience the desired effects of pentazocine.
What special precautions should I follow?
Before taking pentazocine,
- tell your doctor and pharmacist if you are allergic to pentazocine, naloxone, any other medications, or any of the ingredients in pentazocine tablets. Ask your doctor or pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: medications for migraine headaches such as almotriptan (Axert), eletriptan (Relpax), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Alsuma, Imitrex, in Treximet), and zolmitriptan (Zomig); medications for cough, cold, or allergies; 5HT3 serotonin blockers such as alosetron (Lotronex), dolasetron (Anzemet), granisetron (Kytril), ondansetron (Zofran, Zuplenz), or palonosetron (Aloxi); selective serotonin-reuptake inhibitors such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem, in Symbyax), fluvoxamine (Luvox), paroxetine (Brisdelle, Prozac, Pexeva), and sertraline (Zoloft); serotonin and norepinephrine reuptake inhibitors such as desvenlafaxine (Khedezla, Pristiq), duloxetine (Cymbalta), milnacipran (Savella), and venlafaxine (Effexor); tramadol; trazodone (Oleptro); and tricyclic antidepressants ('mood elevators') such as amitriptyline, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Silenor), imipramine (Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil). Also tell your doctor or pharmacist if you are taking or receiving any of the following medications or have stopped taking them within the past 2 weeks: monoamine oxidase (MAO) inhibitors such as isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), rasagiline (Azilect), selegiline (Emsam, Eldepryl, Zelapar), and tranylcypromine (Parnate). Many other medications may also interact with pentazocine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor what herbal products you are taking, especially St. John's wort.
- tell your doctor if you have or have ever had problems urinating; seizure disorders; lung, liver, kidney, thyroid, gallbladder, or heart disease.
- tell your doctor if you are breastfeeding.
- you should know that this medication may decrease fertility in men and women. Talk to your doctor about the risks of taking pentazocine.
- you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
- talk to your doctor about the safe use of this medication if you are 65 years of age or older. Older adults should not usually take pentazocine because it is not as safe as other medications that can be used to treat the same condition.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking pentazocine.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget to take a dose?
This medication usually is taken as needed. If your doctor has told you to take pentazocine regularly, take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What should I do in case of overdose?
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
While taking pentazocine, you should talk to your doctor about having a rescue medication called naloxone readily available (e.g., home, office). Naloxone is used to reverse the life-threatening effects of an overdose. It works by blocking the effects of opiates to relieve dangerous symptoms caused by high levels of opiates in the blood. Your doctor may also prescribe you naloxone if you are living in a household where there are small children or someone who has abused street or prescription drugs. You should make sure that you and your family members, caregivers, or the people who spend time with you know how to recognize an overdose, how to use naloxone, and what to do until emergency medical help arrives. Your doctor or pharmacist will show you and your family members how to use the medication. Ask your pharmacist for the instructions or visit the manufacturer's website to get the instructions. If symptoms of an overdose occur, a friend or family member should give the first dose of naloxone, call 911 immediately, and stay with you and watch you closely until emergency medical help arrives. Your symptoms may return within a few minutes after you receive naloxone. If your symptoms return, the person should give you another dose of naloxone. Additional doses may be given every 2 to 3 minutes, if symptoms return before medical help arrives.
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
Symptoms of overdose may include the following:
- slow or shallow breathing
- difficulty breathing
- extreme sleepiness
- unable to respond or wake up
What side effects can this medicine cause?
Pentazocine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- feeling very tired
- lightheadedness
- drowsiness
- mood changes
- headache
- upset stomach
- constipation
- stomach pain
- rash
- difficulty urinating
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
- difficulty breathing
- changes in heartbeat
- agitation, hallucinations (seeing things or hearing voices that do not exist), fever, sweating, confusion, fast heartbeat, shivering, severe muscle stiffness or twitching, loss of coordination, nausea, vomiting, or diarrhea
- nausea, vomiting, loss of appetite, weakness, or dizziness
- inability to get or keep an erection
- irregular menstruation
- decreased sexual desire
- fainting
Pentazocine may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( http://www.fda.gov/Safety/MedWatch ) or by phone (1-800-332-1088).
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org
What other information should I know?
Keep all appointments with your doctor and laboratory. Your doctor may order certain lab tests to check your body's response to pentazocine.
Before having any laboratory test (especially those that involve methylene blue), tell your doctor and the laboratory personnel that you are taking pentazocine.
Do not let anyone else take your medication. Pentazocine is a controlled substance. Prescriptions may be refilled only a limited number of times; ask your pharmacist if you have any questions.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.