Medicinecontrolled

Pentazocine

An opioid painkiller (combined with naloxone in tablets) for severe pain.

Clinical information

Common uses

severe pain when other treatments are inadequate

Common side effects

feeling sick or vomiting
dizziness or lightheadedness
sedation
constipation
sweating

Cautions

risk of addiction, misuse, overdose and death
can cause dangerous breathing problems, especially with sedatives or alcohol
not for people with severe asthma attacks or bowel blockage
long use in pregnancy causes newborn withdrawal

Interactions

benzodiazepines and other sedatives (risk of coma and death)
alcohol
other opioids
gabapentin or pregabalin
muscle relaxants
serotonergic drugs (risk of serotonin syndrome)

Pregnancy: avoid long use — newborn withdrawal risk; talk to your doctor

Reference information, not medical advice — always follow your doctor or pharmacist. Source: DailyMed, dailymed.nlm.nih.gov, pentazocine and naloxone label, setid a28450a0-ac93-4235-b9a6-58cdf24773cb (accessed 2026-08-16)

Approved brands & formulations4

Brand name	Dosage form	Strength	Importer	Category
Pentazocine	Parenteral ( Injection )	30 mg / ml	MFDA designated importers with Pre Authorization approval before import	controlled
Pentazocine	Tablet	25 mg	MFDA designated importers with Pre Authorization approval before import	controlled
Pentazocine	Parenteral ( Injection )	30 mg	MFDA designated importers with Pre Authorization approval before import	controlled
Riddof	Parenteral ( Injection )	30mg/ml	—	controlled