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Brand Name :
Talwin NX
Synonyms :
pentazocine/naloxone
Class :
Analgesics, Opioid Partial Agonist, Opioid Combos
Brand Name :
Talwin NX
Synonyms :
pentazocine/naloxone
Class :
Analgesics, Opioid Partial Agonist, Opioid Combos
Dosage Forms & Strengths
Tablet
50mg/0.5mg- pentazocine/naloxone
Indicated for Moderate to Severe Pain :
1
Tablet
Orally 
every 3-4 hours
or may increase to 2 tablets if required
Do not exceed 12 tablets a day
Dose Adjustments
Renal Impairment CrCl if 10–50 mL/min: 75% of the recommended adult dose CrCl if less than 10 mL/min: 50% of the typical adult dose Hepatic Impairment Use caution
Dosage Forms & Strengths
Tablet
50mg/0.5mg- pentazocine/naloxone
Age >12 years:
Indicated for Moderate to Severe Pain
1 tablet orally every 3-4hours, increase to 2 tablets if required
Do not exceed 12 tablets a day
Dose Adjustments
Renal Impairment
CrCl if 10–50 mL/min: 75% of the recommended adult dose
CrCl if less than 10 mL/min: 50% of the typical adult dose
Hepatic Impairment
Use caution
Refer adult dosing
Actions and Spectrum:
The combination of pentazocine and naloxone is designed to provide effective pain relief while also reducing the risk of opioid misuse, abuse, and dependence. Naloxone is added to the medication to prevent the abuse of pentazocine, as it can cause euphoria and addiction when taken in high doses.
The addition of naloxone to pentazocine also helps to reduce the risk of respiratory depression, which is a potentially life-threatening side effect of opioid use. If someone takes too much pentazocine/naloxone, the naloxone can quickly reverse the effects of the opioid and prevent respiratory depression.
Overall, the combination of pentazocine and naloxone provides a broader spectrum of action than pentazocine alone, making it a useful tool in the management of pain in patients who are at risk of opioid misuse or abuse.
Post marketing reports
Facial edema
Anaphylaxis
Rash
Pruritus
Dermatitis
Rash
Erythema multiforme
Urticaria
Toxic epidermal necrolysis
Stevens-Johnson syndrome
Black Box Warning:
The black box warning for pentazocine/naloxone relates to the risk of addiction, abuse, and misuse of the medication, which can lead to overdose and death.
Contraindication/Caution:
Pregnancy warnings:   
Pregnancy Category: C
Lactation:Â Excreted into human milk is known
Pregnancy Categories:     
Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester.
Category B: There were lack of studies on pregnant women and no evidence of risk to the foetus in animal experiments.
Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.
Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.
Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.
Category N: There is no data available for the drug under this category
Pharmacology:
The combination of pentazocine/naloxone is used to treat moderate to severe pain. naloxone is included in the medication to prevent misuse or abuse of pentazocine, as it can trigger opioid withdrawal symptoms if the medication is injected or snorted. The addition of naloxone discourages individuals from using the medication in ways that are not prescribed and helps prevent addiction.
Pharmacodynamics:
pentazocine is an opioid analgesic medication that works by binding to mu, kappa, and delta opioid receptors in the brain and spinal cord, which reduces the perception of pain. naloxone is an opioid antagonist that works by blocking the effects of opioids by binding to the same receptors but not activating them. When naloxone is combined with pentazocine, it helps to reduce the abuse potential of the medication.
Pharmacokinetics:
Absorption
After oral administration, both pentazocine and naloxone are rapidly absorbed from the gastrointestinal tract. The onset of action is typically within 15 to 30 minutes.
Distribution
pentazocine and naloxone are extensively distributed throughout the body. Pentazocine has a volume of distribution of about 3.3 L/kg, while naloxone has a volume of distribution of about 1.3 L/kg. Both drugs cross the blood-brain barrier and placenta.
Metabolism
pentazocine is primarily metabolized in the liver by N-demethylation to form norpethidine, which is further metabolized to inactive metabolites. Naloxone undergoes extensive first-pass metabolism in the liver to form its active metabolite, naloxone-3-glucuronide, which is then excreted in the urine.
Elimination and Excretion
Both pentazocine and naloxone are primarily excreted in the urine, with about 60-80% of pentazocine and 50-70% of naloxone excreted unchanged. The elimination half-life of pentazocine is about 3-4 hours, while the elimination half-life of naloxone is about 1-2 hours.
Administration:
The combination of the two drugs is used to prevent the abuse potential of pentazocine and minimize the risk of respiratory depression. The administration of pentazocine/naloxone should be done according to the instructions of the prescribing healthcare provider.
It is typically administered by injection or oral route, depending on the formulation. The dosage and frequency of administration will also depend on the individual’s condition, pain severity, and other factors
Patient information leaflet
Generic Name: pentazocine/naloxone
Why do we use pentazocine/naloxone?
pentazocine/naloxone is used for the management of moderate to severe pain. It is a combination medication that contains pentazocine, an opioid analgesic, and naloxone, an opioid antagonist. The combination of these two drugs is used to reduce the abuse potential of pentazocine while still providing effective pain relief.
pentazocine can be addictive and may lead to dependence, which is why the addition of naloxone helps to minimize the risk of abuse and dependence. naloxone blocks the effects of opioids, including pentazocine, and can prevent the respiratory depression that can occur with opioid use.
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