Is 1350mg toxic to a person weighing 20 stone?

Toxicity of 1350mg Medication for a Person Weighing 20 Stone

A 1350mg dose is not inherently toxic for a person weighing 20 stone (280 pounds/127kg), as this weight allows for higher absolute dosing compared to lower-weight individuals. 1, 2

Dosing Considerations Based on Weight

• For most medications requiring weight-based dosing, a 20 stone individual would typically have a higher maximum tolerated dose compared to average-weight individuals 3
• Standard activated charcoal dosing guidelines recommend 1-2 g/kg body weight, which would equate to 127-254g for a person weighing 20 stone - far above 1350mg 1, 2
• The American Society of Clinical Oncology guidelines specifically recommend using actual body weight for medication dosing in obese patients, noting that toxicity is often not increased when appropriate weight-based dosing is used 3

Toxicity Assessment Factors

• Toxicity is not simply a property of a drug but depends on the specific drug-host interaction 4
• Without knowing the specific medication in question, a complete toxicity assessment cannot be made, as different drugs have vastly different therapeutic and toxic ranges 5
• For many medications, obese patients may actually experience less pronounced side effects at weight-appropriate doses compared to non-obese patients 3

Important Considerations for Specific Drug Classes

• For hydroxychloroquine, doses >5.0 mg/kg dramatically increase risk of toxicity, which would mean doses above 635mg for a 127kg person could potentially be concerning 3
• For vitamin A supplements, chronic toxicity can result from daily amounts >25,000 IU for extended periods, but 1350mg is well below this threshold 3
• For tyrosine kinase inhibitors, high daily doses (>1000mg) may increase risk of adverse drug reactions, particularly if the patient has impaired hepatic or renal function 3

Clinical Decision Making

• The assessment of toxicity should include consideration of:

  • Renal function (as many drugs are cleared by the kidneys) 3
  • Hepatic function (for drugs metabolized by the liver) 3
  • Age (elderly patients may have altered drug metabolism) 3
  • Concomitant medications that might cause drug interactions 3

• For chemotherapeutic agents specifically, full weight-based dosing is recommended even for morbidly obese patients, with toxicity monitoring as would be done for any patient 3

Conclusion

Without knowing the specific medication, a 1350mg dose for a 20 stone individual is not inherently toxic based solely on the weight-dose relationship. The appropriate dose depends on the specific medication, the patient's organ function, and other individual factors 4, 5.