What is the recommended dose of tramadol (ultram) per kilogram for patients with normal renal and hepatic function, considering age safety guidelines from the FDA?

Recommended Dosage of Tramadol Per Kilogram

The recommended dose of tramadol for adults with normal renal and hepatic function is 50-100 mg every 4-6 hours as needed, with a maximum daily dose of 400 mg for immediate-release formulations or 300 mg for extended-release formulations. 1

Adult Dosing Guidelines

• Initial dose: 50-100 mg orally every 4-6 hours as needed
• Maximum daily dose:
  • 400 mg/day for immediate-release formulations
  • 300 mg/day for extended-release formulations
• Target maintenance dose: 200 mg/day

Tramadol is approximately one-tenth as potent as morphine 1, functioning as a dual-mechanism analgesic with both weak mu-opioid receptor activity and inhibition of norepinephrine and serotonin reuptake 2.

Pediatric Dosing

For children with normal renal and hepatic function:

• Recommended dose: 1-2 mg/kg orally every 4-6 hours
• Maximum daily dose: 8 mg/kg/day, not to exceed 400 mg/day 3

Special Populations and Dose Adjustments

Elderly Patients (≥75 years)

• Dose reduction required to reduce risk of seizures 4
• Consider starting at the lower end of the dosing range (50 mg every 6 hours)

Hepatic Impairment

• Dose reduction required 1
• For moderate hepatic impairment: reduce dose by 50% and extend dosing interval
• For severe hepatic impairment: avoid use

Renal Impairment

• Dose adjustment needed for creatinine clearance <30 mL/min 1
• Extend dosing interval to every 12 hours
• Consider 50-100 mg twice daily maximum

Important Safety Considerations

1. Seizure risk: Tramadol can lower seizure threshold, particularly at higher doses or in predisposed patients 1

2. Serotonin syndrome: Avoid concomitant use with:

   • Selective serotonin reuptake inhibitors (SSRIs)
   • Serotonin-norepinephrine reuptake inhibitors (SNRIs)
   • Tricyclic antidepressants
   • MAO inhibitors 4, 1

3. Hepatic metabolism: Tramadol is primarily metabolized in the liver via CYP2D6 to its active M1 metabolite, which has higher opioid receptor affinity than the parent drug 5, 2

4. CYP2D6 polymorphism: Poor metabolizers may experience reduced analgesic effect 1

5. Bioavailability: Tramadol has approximately 68% oral bioavailability with peak concentrations reached within 2 hours 5

Clinical Pearls

• For patients with liver cirrhosis, no more than 50 mg of tramadol should be administered within 12 hours due to increased bioavailability (2-3 fold) 4

• The analgesic effect of a single oral dose of tramadol 100 mg lasts approximately 6 hours 5

• Adverse effects, particularly nausea, are dose-dependent; consider starting with lower doses and titrating up to improve tolerability 5

• Unlike traditional opioids, tramadol has minimal effects on respiratory function at therapeutic doses, making it potentially safer for certain populations 6, 7

• Tramadol has lower potential for dependence compared to traditional opioids, but still requires monitoring 5