What Is The Lethal Dose of Fentanyl?
Before discussing the potentially lethal dose of fentanyl, it may be useful to establish some perspective for those not familiar with the metric system. There are approximately 28.35 grams to an ounce. One milligram (1 mg) is equal to 1/1000 of a gram. One microgram is equal to 1/1000 of one milligram.
The medicinal doses associated with some of the more well-known narcotic medications, such as morphine, hydrocodone (the opiate drug in medications like Vicodin), and oxycodone (the opiate substance in medications like OxyContin) are often given in milligrams. Medicinal doses associated with fentanyl are often given in micrograms.
This illustrates the potency of opiate drugs in general and the increased potency associated with fentanyl compared to these other very potent narcotic medications.
According to the book
Opiate Receptors and Antagonists: From Bench to Clinic, the following amounts are generally considered to be lethal doses for these opiate drugs for an average person who has not developed tolerance:
- The lethal dose of fentanyl is generally stated to be 2 milligrams. This lethal dose considers that the individual has not developed significant tolerance; however, even in individuals with significant tolerance, the lethal dose of fentanyl is extremely small compared to the potential lethal doses of many other opiate drugs.
- Morphine doses of over 200 mg are considered to be lethal. Individuals with hypersensitivity to opiate drugs may experience lethal effects from significantly lower amounts, and individuals with tolerance may need extremely high amounts of morphine before they experience lethal overdose effects.
- The lethal dose for heroin is generally reported as being between 75 and 375 mg.
- The lethal dose for hydrocodone is generally stated to be around 90 mg. However, taking hydrocodone with acetaminophen (e.g., as in Vicodin and other medications) can result in lethal effects occurring at lower doses.
- A single dose of 40 mg or more of oxycodone may produce lethal effects in some individuals. Individuals who take controlled-release forms of oxycodone and take more than 80 mg per day may experience overdose effects if they have not developed significant tolerance.
Based on the above figures, one can calculate that
the lethal dose for fentanyl is approximately 100 times less than the lethal dose for morphine.
In addition, when individuals mix drugs, such as fentanyl dosing in conjunction with heroin, the potential amount of a lethal dose of fentanyl is drastically reduced to the point of being so small that normal individuals might not be able to measure it.
In most cases, lethal doses of any drug will vary depending on who is taking the drug. The lethal dose for a small child or a 100-pound woman will be significantly smaller than the lethal dose for a 300-pound man.
In addition, individuals who have established significant tolerance to a substance will require significantly higher amounts of the drug in order to experience an overdose or lethal effects compared to individuals who have not established a tolerance for the drug.
In many cases, the mode of administration may play a role in how much of the drug is actually delivered to the individual’s system. For instance, taking a drug orally typically results in less of the drug entering a person’s system than snorting or injecting it. Moreover, snorting or injecting opiate drugs results in their actions being experienced far more quickly than taking them orally.
