Pentazocine Side Effects

Medically reviewed by Drugs.com. Last updated on Apr 13, 2025.

Applies to pentazocine: oral tablets.

Side effects include:

Dizziness, lightheadedness, euphoria, sedation, nausea.

For healthcare professionals

Applies to pentazocine: injectable solution.

General adverse events

The most commonly occurring adverse reactions have included nausea, dizziness or lightheadedness, vomiting, and euphoria.

Dermatologic

• Postmarketing reports: Soft tissue induration, nodules and cutaneous depressions at injection sites; ulceration (sloughing), severe sclerosis of the skin and subcutaneous tissues and, rarely, underlying muscle; diaphoresis, sting on injection, flushed skin including plethora, dermatitis including pruritus^[Ref]

Hypersensitivity

• Postmarketing reports: Anaphylaxis, facial edema, toxic epidermal necrolysis^[Ref]

Nervous system

• Postmarketing reports: Dizziness, lightheadedness, sedation, headache, weakness, flushing, syncope, tremor, paresthesia

Opioids:

• Postmarketing reports: Serotonin syndrome^[Ref]

Serotonin syndrome has been reported during concomitant use of opioids with serotonergic drugs.^[Ref]

Psychiatric

• Postmarketing reports: Depression, euphoria, confusion, disorientation, disturbed dreams, insomnia, irritability, excitement, hallucinations^[Ref]

Respiratory

• Postmarketing reports: Respiratory depression, dyspnea, transient apnea (in infants whose mothers received this drug during labor)^[Ref]

Cardiovascular

• Postmarketing reports: Circulatory depression, shock, hypertension, tachycardia, syncope^[Ref]

Gastrointestinal

• Postmarketing reports: Nausea, vomiting, constipation, dry mouth, taste alteration, diarrhea and cramps^[Ref]

Hematologic

• Postmarketing reports: Depression of the white blood cell count (especially granulocytes), moderate transient eosinophilia^[Ref]

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

Other

• Postmarketing reports: Tinnitus, chills^[Ref]

Ocular

• Postmarketing reports: Visual blurring and focusing difficulty, blurred vision, diplopia, miosis, nystagmus^[Ref]

Genitourinary

• Postmarketing reports: Urinary retention, alteration in rate or strength of labor contractions^[Ref]

Endocrine

Opioids:

• Postmarketing reports: Adrenal insufficiency, Androgen deficiency

Cases of adrenal insufficiency have been reported with opioid use, generally use greater than 1 month. Cases of androgen deficiency have been reported with chronic opioid use.

See also:

Further information

Pentazocine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer