Pentazocine is a synthetic opioid that has agonist activity at kappa and weak antagonist activity at Mu receptors.
- Pentazocine is used to relieve moderate to severe pain.
- Its analgesic activity is almost equal to that of morphine.
- It has a short duration of action i.e 3-4 hours.
- Pentazocine is Available in Combination with Naloxone To Avoid its misuse various
- Available in various dosage forms like Tablet and Injection.
- 50mg of pentazocine orally is almost equal to 60mg of oral codeine in analgesic activity.
- Nausea and vomiting are common with pentazocine.
- Dependence and tolerance can occur but is less as compared to that of morphine.
- Pentazocine can produce mental confusion, tachycardia, dysphoria, Hypertension, and Palpitations.
- Also, Causes Trouble passing urine or change in the amount of urine.
- Should be used with cautions in the following conditions; cardiac arrhythmias, Phaeochromocytoma, Pancreatitis, Arterial or pulmonary hypertension, And acute myocardial infarction.
- This drug can enter the foetal circulation and has the potential to cause opioid effects including central depression, can cause respiratory depression and withdrawal symptoms in the neonates if used during delivery.
- There is very less data on the secretion of pentazocine in breast milk, so it is recommended that infants of nursing mothers who are receiving high doses of pentazocine, be appropriately monitored
- Less Likely To Cause constipation.
- It is contraindicated in acute respiratory depression and in patients dependent on opioids, heart failure secondary to chronic lung disease, acute porphyria.
- Pentazocine may interact with the following medicines Like antihistamines,alcohol,atropine,anxiolytics or sleep,Medications,oxybutynin, tolterodine,certain medicines for depression like amitriptyline, fluoxetine, sertraline,certain medicines for stomach problems like dicyclomine, hyoscyamine,certain medicines for seizures like phenobarbital, primidone,certain medicines for travel sickness like scopolamine,certain medicines for Parkinson’s disease like benztropine, trihexyphenidyl,general anesthetics like halothane, isoflurane, methoxyflurane, propofol,ipratropium,MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate,medicines that relax muscles for surgery,local anesthetics like lidocaine, pramoxine, tetracaine,other narcotic medicines for pain or cough,phenothiazines like chlorpromazine, mesoridazine, prochlorperazine, thioridazine.
- Dosage for Adults: The usual initial dosage is 50mg every 3-4 hours after meals followed by 50-100mg every three to four hours.The maximum dose is 600 mg daily.
- Dose For Children under 12 years: It is recommended that another dosage form ie tablets, be used as appropriate for this age group.