Pentazocine

The Basics

What is Pentazocine?

Used to treat moderate to severe pain during surgery or child birth.

Brand names for Pentazocine

Talwin Nx

How Pentazocine is classified

Analgesics – Opioid, Narcotics, Narcotic Antagonists, Opiates

Pentazocine During Pregnancy

Pentazocine pregnancy category

Category N/ANote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Pentazocine while pregnant

Prolonged use of opioid analgesics during pregnancy may cause neonatal opioid withdrawal syndrome. Available data with TALWIN in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage. In animal reproduction studies, pentazocine administered subcutaneously to pregnant hamsters during the early gestational period produced neural tube defects (i.e., exencephaly and cranioschisis) at 4.4 times the maximum daily dose . Based on animal data, advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Prolonged use of opioid analgesics during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly . Labor Or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. TALWIN is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including TALWIN, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Patients receiving TALWIN during labor have experienced no adverse effects other than those that occur with commonly used analgesics. Data Animal Data In a published report, a single dose of pentazocine administered to pregnant hamsters on Gestation Day 8 increased the incidence of neural tube defects (exencephaly and cranioschisis) at a dose of 196 mg/kg, SC (4.4-times the maximum daily dose (MDD) of 360 mg/day pentazocine on a body surface area basis). No evidence of neural tube defects were reported following a dose of 98 mg/kg (2.2 times the MDD).

Taking Pentazocine While Breastfeeding

What are recommendations for lactation if you're taking Pentazocine?

No information is available on the use of pentazocine during breastfeeding. Maternal use of oral narcotics during breastfeeding can cause infant drowsiness, central nervous system depression and even death. Newborn infants seem to be particularly sensitive to the effects of even small dosages of narcotic analgesics. Once the mother’s milk comes in, it is best to provide pain control with a nonnarcotic analgesic and limit maternal intake of pentazocine to a few days at a low dosage with close infant monitoring. If the baby shows signs of increased sleepiness (more than usual), difficulty breastfeeding, breathing difficulties, or limpness, a physician should be contacted immediately. Other agents are preferred over pentazocine during breastfeeding.[1]

Maternal / infant drug levels

No information is available on the use of pentazocine during breastfeeding. Maternal use of oral narcotics during breastfeeding can cause infant drowsiness, central nervous system depression and even death. Newborn infants seem to be particularly sensitive to the effects of even small dosages of narcotic analgesics. Once the mother’s milk comes in, it is best to provide pain control with a nonnarcotic analgesic and limit maternal intake of pentazocine to a few days at a low dosage with close infant monitoring. If the baby shows signs of increased sleepiness (more than usual), difficulty breastfeeding, breathing difficulties, or limpness, a physician should be contacted immediately. Other agents are preferred over pentazocine during breastfeeding.[1]

Possible effects of Pentazocine on milk supply

Pentazocine can increase serum prolactin.[2][3] However, the prolactin level in a mother with established lactation may not affect her ability to breastfeed.

Possible alternatives to Pentazocine

Acetaminophen, Butorphanol, Hydromorphone, Ibuprofen, Morphine.