Pentazocine (Injection)

Pentazocine (Injection) is used to relieve moderate to severe pain. It may also be used before surgery or with a general anesthetic (medicine that puts you to sleep). Pentazocine belongs to a group of medicines called narcotic analgesics (pain medicines). It works on the central nervous system (CNS) to relieve pain.

When a narcotic medicine is used for a long time, it may become habit-forming, leading to mental or physical dependence. However, people with ongoing pain should not let the fear of dependence prevent them from using narcotics to relieve their pain. Mental dependence (addiction) is not likely to happen when narcotics are used for this purpose. Physical dependence may cause withdrawal side effects if treatment is stopped suddenly. However, severe withdrawal side effects can usually be avoided by gradually lowering the dose over time before stopping treatment completely.

This medicine is available only with your doctor's prescription.

It is very important for your doctor to monitor the progress of you or your child while using this medicine. This helps your doctor determine if the medicine is effective and if you or your child should keep using it.

This medicine can be habit-forming. If you or your child feel that the medicine is not working as well, do not take more than the prescribed dose. Call your doctor for guidance.

Long-term use of narcotics can lead to severe constipation. To help prevent this, your doctor may recommend that you or your child take laxatives, drink plenty of fluids, or increase fiber intake in your diet. Follow these directions carefully, as ongoing constipation can lead to more serious issues.

This medicine may cause skin or tissue damage at the injection site. Inform your doctor immediately if you notice any of these symptoms at the injection site: depressed or indented skin, blue-green to black skin discoloration, or pain, redness, or peeling of the skin.

This medicine will enhance the effects of alcohol and other CNS depressants (medicines that can cause drowsiness or reduce alertness). Examples of CNS depressants include antihistamines, allergy or cold medicines, sedatives, tranquilizers, sleeping medicines, other prescription pain medicines or narcotics, seizure medications or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Consult your doctor before you or your child take any of these medications while using this medicine.

This medicine may cause dizziness, drowsiness, confusion, or disorientation. Be sure to know how you react to this medicine before driving, operating machinery, or doing anything else that could be dangerous if you are dizzy or not alert.

This medicine may trigger allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Contact your doctor without delay if you or your child experience a rash, itching, hoarseness, difficulty breathing, trouble swallowing, or swelling of the hands, face, or mouth while using this medicine.

If you or your child have been using this medicine regularly for several weeks or longer, do not stop suddenly without consulting your doctor. Your doctor may advise you to gradually reduce the dosage before stopping completely. This approach may help prevent a worsening of your condition and lower the risk of withdrawal symptoms, such as abdominal cramps, anxiety, fever, nausea, runny nose, sweating, tremors, or difficulty sleeping.

Excessive use of this medicine may lead to infertility (the inability to have children). Discuss with your doctor before using this medicine if you plan to have children.

Using this medicine during pregnancy may lead to neonatal withdrawal syndrome in newborns. Notify your doctor immediately if your baby shows signs of an abnormal sleep pattern, diarrhea, a high-pitched cry, irritability, shakiness or tremors, weight loss, vomiting, or does not gain weight.

Do not take other medicines unless you have discussed them with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

In deciding to use a medication, the chances of taking the drug must be weighed against the beneficial it will do. This is a decision you and your clinician will make. For this drug, the following should be considered:

Allergies

Inform your clinician if you have ever had any unusual or allergic reaction to this drug or any other drugs. As well inform your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of pentazocine injection in children 1 to 16 years of age. Safety and efficacy have not been established in children younger than 1 year of age.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific issues that would limit the usefulness of pentazocine injection in the elderly. Nevertheless, elderly patients may be more sensitive to the effects of pentazocine injection than younger adults, and are more likely to have age-related kidney issues, which may require caution and an adjustment in the dose for patients receiving pentazocine injection.

Breast Feeding

There are no adequate studies in women for determining infant chance when using this drug during breastfeeding. Weigh the potential benefits against the potential chances prior to using this drug while breastfeeding.

Interactions with Medicines

Although certain medications should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your physician may want to change the dose, or other precautions may be necessary. When you are receiving this drug, it is especially critical that your healthcare professional know if you are using any of the medications listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medications is not recommended. Your doctor may decide not to treat you with this medication or change some of the other drugs you take.

• Nalmefene

Using this medication with any of the following medications is normally not recommended, but may be required in some cases. If both drugs are prescribed together, your physician may change the dose or how often you use one or both of the medicines.

• Acepromazine
• Alfentanil
• Almotriptan
• Alprazolam
• Amifampridine
• Amineptine
• Amiodarone
• Amitriptyline
• Amitriptylinoxide
• Amobarbital
• Amoxapine
• Amphetamine
• Amprenavir
• Aprepitant
• Armodafinil
• Asenapine
• Atazanavir
• Baclofen
• Benperidol
• Benzhydrocodone
• Benzphetamine
• Boceprevir
• Bosentan
• Bromazepam
• Bromopride
• Brompheniramine
• Buprenorphine
• Bupropion
• Buspirone
• Butabarbital
• Butorphanol
• Calcium Oxybate
• Cannabidiol
• Cannabis
• Carbamazepine
• Carisoprodol
• Carphenazine
• Cetirizine
• Chloral Hydrate
• Chlordiazepoxide
• Chlorpheniramine
• Chlorpromazine
• Chlorzoxazone
• Ciprofloxacin
• Citalopram
• Clarithromycin
• Clobazam
• Clomipramine
• Clonazepam
• Clorazepate
• Clozapine
• Cobicistat
• Cocaine
• Codeine
• Conivaptan
• Crizotinib
• Cyclosporine
• Daridorexant
• Darunavir
• Delavirdine
• Desipramine
• Desmopressin
• Desvenlafaxine
• Dexamethasone
• Dexmedetomidine
• Dextroamphetamine
• Dextromethorphan
• Dezocine
• Diazepam
• Dibenzepin
• Dichloralphenazone
• Difenoxin
• Diltiazem
• Diphenhydramine
• Diphenoxylate
• Dolasetron
• Donepezil
• Doxepin
• Dronedarone
• Droperidol
• Duloxetine
• Efavirenz
• Eletriptan
• Enflurane
• Enzalutamide
• Erythromycin
• Escitalopram
• Esketamine
• Eslicarbazepine Acetate
• Estazolam
• Eszopiclone
• Ethchlorvynol
• Ethopropazine
• Ethylmorphine
• Etravirine
• Fenfluramine
• Fentanyl
• Flibanserin
• Fluconazole
• Fluoxetine
• Fluphenazine
• Flurazepam
• Fluspirilene
• Fluvoxamine
• Fosamprenavir
• Fosaprepitant
• Fosphenytoin
• Fospropofol
• Frovatriptan
• Furazolidone
• Gabapentin
• Gabapentin Enacarbil
• Gepirone
• Granisetron
• Halazepam
• Haloperidol
• Halothane
• Hexobarbital
• Hydrocodone
• Hydromorphone
• Hydroxyamphetamine
• Hydroxytryptophan
• Hydroxyzine
• Idelalisib
• Imatinib
• Imipramine
• Indinavir
• Iproniazid
• Isocarboxazid
• Isoflurane
• Itraconazole
• Ivacaftor
• Ketamine
• Ketazolam
• Ketobemidone
• Ketoconazole
• Lacosamide
• Lasmiditan
• Lemborexant
• Levocetirizine
• Levomilnacipran
• Levorphanol
• Linezolid
• Lisdexamfetamine
• Lithium
• Lofepramine
• Lofexidine
• Lomitapide
• Lopinavir
• Lorazepam
• Lorcaserin
• Loxapine
• Lumacaftor
• Magnesium Oxybate
• Meclizine
• Melitracen
• Melperone
• Meperidine
• Mephobarbital
• Meprobamate
• Meptazinol
• Mesoridazine
• Metaxalone
• Methadone
• Methamphetamine
• Methdilazine
• Methocarbamol
• Methohexital
• Methotrimeprazine
• Methylene Blue
• Metoclopramide
• Mibefradil
• Midazolam
• Mifepristone
• Milnacipran
• Mirtazapine
• Mitotane
• Moclobemide
• Modafinil
• Molindone
• Moricizine
• Morphine
• Nafcillin
• Nalbuphine
• Naratriptan
• Nefazodone
• Nelfinavir
• Nevirapine
• Nialamide
• Nicomorphine
• Nilotinib
• Nitrazepam
• Nitrous Oxide
• Nortriptyline
• Olanzapine
• Ondansetron
• Opipramol
• Opium
• Opium Alkaloids
• Orphenadrine
• Oxazepam
• Oxcarbazepine
• Oxycodone
• Oxymorphone
• Palbociclib
• Palonosetron
• Papaveretum
• Paregoric
• Paroxetine
• Pentobarbital
• Perampanel
• Perazine
• Periciazine
• Perphenazine
• Phenelzine
• Phenobarbital
• Phenytoin
• Pimozide
• Piperacetazine
• Pipotiazine
• Piritramide
• Posaconazole
• Potassium Oxybate
• Prazepam
• Prednisone
• Pregabalin
• Primidone
• Procarbazine
• Prochlorperazine
• Promazine
• Promethazine
• Propofol
• Protriptyline
• Quazepam
• Quetiapine
• Ramelteon
• Ranitidine
• Ranolazine
• Rasagiline
• Remifentanil
• Remimazolam
• Remoxipride
• Rifabutin
• Rifampin
• Rifapentine
• Ritonavir
• Rizatriptan
• Ropeginterferon Alfa-2b-njft
• Saquinavir
• Scopolamine
• Secobarbital
• Selegiline
• Sertindole
• Sertraline
• Sibutramine
• Sodium Oxybate
• St John's Wort
• Sufentanil
• Sulpiride
• Sumatriptan
• Suvorexant
• Tapentadol
• Telaprevir
• Telithromycin
• Temazepam
• Thiethylperazine
• Thiopental
• Thiopropazate
• Thioridazine
• Tianeptine
• Tilidine
• Tizanidine
• Tolonium Chloride
• Topiramate
• Tramadol
• Tranylcypromine
• Trazodone
• Triazolam
• Trifluoperazine
• Trifluperidol
• Triflupromazine
• Trimeprazine
• Trimipramine
• Tryptophan
• Venlafaxine
• Verapamil
• Vilazodone
• Voriconazole
• Vortioxetine
• Zaleplon
• Ziprasidone
• Zolpidem
• Zopiclone
• Zotepine
• Zuranolone

Interactions with Food/Tobacco/Alcohol

Certain drugs should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may as well cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this drug with any of the following may cause an increased chance of certain side effects but may be unavoidable in some cases. If used together, your physician may change the dose or how often you use this drug, or give you special instructions about the use of food, alcohol, or tobacco.

• Ethanol

Other Medical Issues

The presence of other medical issues may affect the use of this medicine. Make sure you inform your doctor if you have any other medical issues, especially:

• Adrenal problems or
• Alcohol abuse, or history of or
• Allergy to sulfites or
• Breathing issues, serious (eg, COPD, hypercapnia, hypoxia) or
• Cor pulmonale or
• Depression, history of or
• Drug dependence, especially with narcotics, or history of or
• Head injuries, history of or
• Mental health issues or
• Weakened physical condition—Use with caution. May increase chance for more serious adverse effects.

• Asthma, severe or
• Respiratory depression (extremely slow breathing) or
• Stomach or bowel blockage (eg, paralytic ileus)—Should not be used in patients with these conditions.

• Heart attack, recent or
• Heart failure or
• Hypertension (high blood pressure) or
• Seizures, history of—Use with caution. May make these conditions worse.

• Kidney disease or
• Liver disease—Use with caution. The effects may be increased since of slower removal of the medicine from the body.

Along with its necessary effects, a medicine may cause some unwanted effects. Not all of these side effects may happen, but if they do, they might need medical attention.

Check with your doctor or nurse right away if any of the following side effects occur:

Rare

• Black, tarry stools
• blistering, peeling, or loosening of the skin
• chest pain
• chills
• cough
• diarrhea
• fast, pounding, or irregular heartbeat or pulse
• fever
• itching
• joint or muscle pain
• painful or difficult urination
• red, irritated eyes
• red skin lesions, often with a purple center
• shakiness in the legs, arms, hands, or feet
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• swelling or puffiness of the face
• swollen glands
• trembling or shaking of the hands or feet
• trouble breathing
• unusual bleeding or bruising
• unusual tiredness or weakness

Incidence not known

• Blistering, crusting, irritation, itching, or reddening of the skin
• blue-green to black skin discoloration
• bluish lips or skin
• blurred vision
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• cold, clammy skin
• confusion
• cough
• cracked, dry, or scaly skin
• decrease in the frequency of urination
• decrease in urine volume
• depression
• difficult or troubled breathing
• difficulty in passing urine (dribbling)
• dizziness
• fainting
• fast or slow heartbeat
• fast, weak pulse
• flushed skin
• hardening or thickening of the skin
• headache
• increased sweating
• irregular, fast, slow, or shallow breathing
• lightheadedness
• nervousness
• pain, redness, or sloughing of the skin at the injection site
• pale or blue lips, fingernails, or skin
• pounding in the ears
• rapid breathing
• small lumps under the skin at the injection site
• stinging at the injection site
• sweating
• swelling of the lower legs or arms
• tightness in the chest
• very slow breathing
• weight gain

Some side effects may happen that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue, are bothersome, or if you have any questions about them:

More common

• False or unusual sense of well-being
• nausea
• vomiting

Rare

• Change in taste
• confusion about identity, place, and time
• constricted, pinpoint, or small pupils (black part of the eye)
• double vision
• seeing double, hearing, or feeling things that are not there
• stomach cramps
• trouble sleeping
• uncontrolled eye movements

Incidence not known

• Continuing ringing or buzzing or other unexplained noise in the ears
• difficulty having a bowel movement (stool)
• difficulty in focusing the eyes
• disturbed dreams
• drowsiness
• dry mouth
• excitement
• hearing loss
• irritability
• relaxed and calm
• sleepiness
• trouble sleeping
• weakness

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

In the U.S.

• Talwin

Pharmacologic Class: Opioid Agonist/Antagonist

A nurse or other trained health professional will give you or your child this medicine in a hospital. This medicine may be given as a shot under your skin, into a muscles or a vein.

Your doctor will give you a few doses of this medicine until your condition improves, and then switch you or your child to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.