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pethidine

N02AB02

Forms & Strengths

Injection: 50 mg/mL, 100 mg/mL
Oral Syrup: 50 mg/5 mL
Oral Tablet: 50 mg, 100 mg

Adult Dosing

Acute pain (IM/SC/IV): 50-150 mg every 3-4 hours as needed
Obstetric analgesia (IM/SC): 50-100 mg when labor is well established
Max daily dose: Generally not to exceed 600 mg/24 hours due to neurotoxic metabolite accumulation

Pediatric Dosing

Pain (IM/SC/IV): 1-1.5 mg/kg every 4-6 hours as needed
Max single dose: 100 mg

Indications

Management of moderate to severe acute pain
Rigors associated with transfusion reactions
Obstetric analgesia during labor

Mechanism of Action

Full agonist at mu-opioid receptors in the central nervous system
Weak serotonin reuptake inhibitor
Possesses local anesthetic properties via sodium channel blockade

Contraindications

Concomitant monoamine oxidase inhibitor (MAOI) use or use within the past 14 days
Significant respiratory depression
Acute or severe bronchial asthma in an unmonitored setting
Known or suspected gastrointestinal obstruction, including paralytic ileus

Adverse Reactions

Respiratory depression
Central nervous system excitation (seizures, tremors, myoclonus due to normeperidine accumulation)
Serotonin syndrome (when combined with serotonergic agents)
Hypotension, dizziness, and sedation
Nausea, vomiting, and constipation

Drug Interactions

MAOIs: Severe, fatal reactions including hyperpyrexia, excitation, and hypertension
Serotonergic drugs (SSRIs, SNRIs, TCAs): Increased risk of serotonin syndrome
CNS depressants (alcohol, benzodiazepines, general anesthetics): Profound sedation, respiratory depression, and hypotension
CYP3A4 inducers (phenytoin, ritonavir, rifampin): Increased formation of the toxic metabolite normeperidine

Curated Content: Needs Vetting Before Put to Clinical Use