Maternal and neonatal disposition of pethidine in childbirth—A study using quantitative gas chromatography-mass spectrometry

Efficacy and Effects of Parenteral Pethidine or Meptazinol and Regional Analgesia for Pain Relief during Delivery. A Comparative Observational Study

“…Our results however partly support the findings of other studies which reported a stronger respiratory depression effect following pethidine administration [15,16]. This difference is caused by the different receptor affinities of the two opioids -as pethidine binds more strongly to µ2 opioid receptors binding this is assumed to result in respiratory depression -and the longer elimination half-time of pethidine in neonates [13,14].…”

“…It reaches its maximum effect after 30-40 minutes and can be re-administered after 3-6 hours [12]. Its elimination half-life in neonates is around 23 hours because of the neonateʼs immature elimination pathways, while in adults the elimination halflife of pethidine is only 3 hours [13]. The opioid analgesic meptazinol is increasingly being used in obstetrics.…”

Estimation of infant dose and exposure to pethidine and norpethidine via breast milk following patient-controlled epidural pethidine for analgesia post caesarean delivery

“…3 Norpethidine may accumulate after prolonged or high-dose pethidine administration or in renal failure and cause adverse central nervous system effects such as agitation, tremulousness, hallucinations and convulsions. [3][4][5] Metabolism of pethidine is impaired in neonates and infants, 6 and in two separate studies, its half-life was longer than in adults, with mean values of 10.7 h and 22.7 h. 7,8 Pethidine continues to be widely used in birth suites in Australasia and the United Kingdom for labour analgesia via the intramuscular (i.m.) route.…”

Técnicas analgésicas para el parto: alternativas en caso de fallo de la epidural

“…Atraviesa la placenta y alcanza la máxima concentración fetal entre 2-3 h tras su administración, por eso se recomienda administrarla cuando el expulsivo se prevé que sucederá antes de una hora o después de 4 horas, algo bastante difícil de predecir. Además, la normeperidina, su metabolito, es tóxico y tiene una semivida en el neonato de 2,5 días 56 , habiéndose relacionado con problemas neuroconductuales 57 y dificultad para la lactancia a pesar de respetar los "márgenes de seguridad" de la administración de la meperidina 58 . La morfina se usa raramente por sus efectos adversos maternofetales 54,55,59,60 .…”