How do medical professionals figure out the lethal dose of drugs?

In summary, medical professionals, scientists, and other researchers determine the lethal dose of a drug through a combination of methods. This may include conducting animal tests, studying data from human trials, analyzing patterns from overdose cases, and making educated guesses based on available information. Even after a drug is on the market, research continues to determine the safety and potential lethal dose of the drug.
  • #1
Flatland
218
11
How do medical professionals, scientists or whoever studies this stuff figure out the lethal dose of a particular drug? It's not like they can perform experiments on humans. Do they just test them on animals and then extrapolate that to humans? Do they find some kind of pattern from people overdosing? Or is it just an educated guess and a combination of the above?
 
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  • #2
Flatland said:
How do medical professionals, scientists or whoever studies this stuff figure out the lethal dose of a particular drug? It's not like they can perform experiments on humans. Do they just test them on animals and then extrapolate that to humans? Do they find some kind of pattern from people overdosing? Or is it just an educated guess and a combination of the above?
... all of the above.

Researchers are not so concerned with the lethal dose as much as a reasonable safe dose. This properly starts with the stage 1 human trial thought they will likely be other information from animal tests and non-clinical use that will be taken into account. You don't go into a human trial without knowing that the initial dose is harmless. You can then step up doses and closely monitor the results.

Once a drug is on the market, the research does not stop - what may count as a lethal dose and in what circumstances is the sort of thing that can become clear after a few autopsies (and close rescues).

See: phases of clinical trials.
http://www.nlm.nih.gov/services/ctphases.html [Broken]
 
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  • #3
Please search LD50.
 
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  • #4
In medical school pharmacology, the professor said that for a lot of drugs, there accumulates ample overdose data to sufficiently determine the number. Of course I'm not sure if this applies to all or even most drugs, so take it for what it is worth.
Source: Recent pharmacology lecture at an American M.D. school

It is interesting that if you search for "X drug overdose" on a program like Epocrates or LexiComp, if there is not an established LD50 there are usually links to individual case reports from toxicology centers about a patient who at one time took a whole bottle of something and then describes what went on to happen.
Source: personal experience using Epocrates
 
  • #5


Medical professionals and scientists use a variety of methods to determine the lethal dose of drugs. The most common method is through animal studies, where the drug is administered to a group of animals in different doses and the effects are observed. This data is then used to calculate the median lethal dose (LD50), which is the dose that is lethal to 50% of the animals tested.

In addition to animal studies, medical professionals also look at data from human cases of drug overdose to determine the lethal dose. This data is collected from emergency room visits, poison control centers, and autopsy reports. By analyzing this data, patterns can be identified and used to estimate the lethal dose for humans.

Furthermore, medical professionals also take into consideration the pharmacological properties of the drug, such as its potency and how it is metabolized in the body. This information, along with data from animal and human studies, can help to make an educated guess on the lethal dose of a drug.

It is important to note that determining the lethal dose of a drug is not an exact science and can vary depending on factors such as an individual's weight, age, and overall health. Therefore, medical professionals must use caution and continually monitor and adjust dosages to ensure patient safety.
 

1. How do medical professionals determine the lethal dose of drugs?

Medical professionals use a variety of methods to determine the lethal dose of drugs. This includes analyzing the drug's potency, its mechanism of action, and how it affects different organs and systems in the body. They also consider factors such as a person's weight, age, and overall health.

2. What is the LD50 and how is it used to determine the lethal dose?

The LD50, or the median lethal dose, is the amount of a substance that is estimated to be lethal to 50% of a population. It is typically determined through experiments on animals and is used as a starting point for determining the lethal dose in humans.

3. Are there any other factors that can affect the lethal dose of a drug?

Yes, there are several other factors that can affect the lethal dose of a drug. These include individual variations in metabolism and drug interactions with other substances a person may be taking. Additionally, a person's tolerance to a drug can also impact the lethal dose.

4. How do medical professionals account for individual differences in response to drugs?

Medical professionals take into account factors such as a person's age, weight, and overall health to determine the appropriate dose of a drug. They may also consider a person's genetic makeup and any preexisting medical conditions that could affect their response to the drug.

5. Can the lethal dose of a drug change over time?

Yes, the lethal dose of a drug can change over time. This is because the potency and effects of a drug can vary depending on factors such as the purity of the drug, manufacturing processes, and changes in a person's overall health and tolerance to the drug.

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