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Talwin Side Effects

Generic Name: pentazocine

Note: This page contains side effects data for the generic drug pentazocine. It is possible that some of the dosage forms included below may not apply to the brand name Talwin.

For the Consumer

Applies to pentazocine: injection solution

As well as its needed effects, pentazocine (the active ingredient contained in Talwin) may cause unwanted side effects that require medical attention.

If any of the following side effects occur while taking pentazocine, check with your doctor or nurse immediately:

  • 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

Minor Side Effects

Some pentazocine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • False or unusual sense of well-being
  • nausea
  • vomiting
  • Change in taste
  • confusion about identity, place, and time
  • constricted, pinpoint, or small pupils (black part of the eye)
  • double vision
  • seeing double seeing, 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

For Healthcare Professionals

Applies to pentazocine: injectable solution

Nervous system

Nervous system side effects including sweating, dizziness, lightheadedness, hallucinations, sedation, euphoria, headache, confusion, and disorientation have been reported. Weakness, flushing, disturbed dreams, insomnia, and syncope have been reported infrequently. Tremor, chills, paresthesia, irritability, and excitement have been reported rarely.[Ref]


Gastrointestinal side effects including nausea and vomiting have been reported. Constipation has been reported infrequently. Abdominal distress, anorexia, and diarrhea have been reported rarely.[Ref]


Depression of the white blood cell count is usually reversible.[Ref]

Hematologic side effects including depression of the white blood cell count (especially granulocytes) and moderate transient eosinophilia have been reported.[Ref]


Hypersensitivity reactions including rash have been reported infrequently. Urticaria and edema of the face have been reported rarely. One instance of an apparent anaphylactic reaction has been reported.[Ref]


Dermatologic side effects including erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis have been reported rarely.[Ref]


Cardiovascular side effects including a decrease in blood pressure and tachycardia have been reported infrequently.[Ref]


Respiratory side effects including respiratory depression have rarely been reported.[Ref]


Other side effects including tinnitus have been reported.[Ref]


Ocular side effects including visual blurring and focusing difficulty have been reported infrequently.[Ref]


Psychiatric side effects including depression have been reported infrequently.[Ref]


Genitourinary side effects including urinary retention have rarely been reported.[Ref]


1. "Product Information. Talwin NX (pentazocine)." Sanofi Winthrop Pharmaceuticals, New York, NY.

It is possible that some side effects of Talwin may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.