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What Is The Lethal Dose Of Phenylephrine?
Question: I was told about Phenylepherine HCl, I want to know about the toxic dose and lethal dose of this. I was told 3mg./kg. of body weight orally was the toxic dose. What happens at that level, does it happen with other means of ingestion or administration and is it at the same level for those? What is the lethal dose? Does that vary with type of administration and what is it orally? Between toxic and lethal does the person survive and how bad is it for them? I know it is in cold meds at lower strengths. Thank you.
Brief Answer:
LD50 in rats and mice studies have shown to be 350mg/kg and 120mg/kg.
Detailed Answer:
Hello,
Thank you for posting your query here.
There are no particular studies done on human beings to estimate the lethal levels of phenylephrine for obvious reasons. The LD50 value for this medicine in lab rats and mice orally is 350mg/kg and 120mg/kg respectively.
The medicine undergoes extensive first pass metabolism when ingested orally so the oral bioavailability is poor at 38%.
3mg/kg IV bolus infusion can be fatal, since this medicine is a sympathomimetic, it can cause fatal tachyarrhythmias, however, orally or subcutaneously, 3 to 5mg/kg is a perfectly proper dosage.
It is not possible to answer your other questions as there are no reported cases of such toxicity in humans.
For drug to be prescription only medicine, the therapeutic index/window has to be narrow and the potential for abuse high or the adverse effects have to be quite risky.
A drug can remain non-prescription drug if the said drug has a wide therapeutic window and has minimal side effects.
I hope this answers your query, please feel free to write back if you need further clarifications.
Kind regards
LD50 in rats and mice studies have shown to be 350mg/kg and 120mg/kg.
Detailed Answer:
Hello,
Thank you for posting your query here.
There are no particular studies done on human beings to estimate the lethal levels of phenylephrine for obvious reasons. The LD50 value for this medicine in lab rats and mice orally is 350mg/kg and 120mg/kg respectively.
The medicine undergoes extensive first pass metabolism when ingested orally so the oral bioavailability is poor at 38%.
3mg/kg IV bolus infusion can be fatal, since this medicine is a sympathomimetic, it can cause fatal tachyarrhythmias, however, orally or subcutaneously, 3 to 5mg/kg is a perfectly proper dosage.
It is not possible to answer your other questions as there are no reported cases of such toxicity in humans.
For drug to be prescription only medicine, the therapeutic index/window has to be narrow and the potential for abuse high or the adverse effects have to be quite risky.
A drug can remain non-prescription drug if the said drug has a wide therapeutic window and has minimal side effects.
I hope this answers your query, please feel free to write back if you need further clarifications.
Kind regards
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Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
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