- Home
- Angry by Choice
- Catalogue of Organisms
- Chinleana
- Doc Madhattan
- Games with Words
- Genomics, Medicine, and Pseudoscience
- History of Geology
- Moss Plants and More
- Pleiotropy
- Plektix
- RRResearch
- Skeptic Wonder
- The Culture of Chemistry
- The Curious Wavefunction
- The Phytophactor
- The View from a Microbiologist
- Variety of Life
Field of Science
-
-
From Valley Forge to the Lab: Parallels between Washington's Maneuvers and Drug Development4 weeks ago in The Curious Wavefunction
-
Political pollsters are pretending they know what's happening. They don't.4 weeks ago in Genomics, Medicine, and Pseudoscience
-
-
Course Corrections5 months ago in Angry by Choice
-
-
The Site is Dead, Long Live the Site2 years ago in Catalogue of Organisms
-
The Site is Dead, Long Live the Site2 years ago in Variety of Life
-
Does mathematics carry human biases?4 years ago in PLEKTIX
-
-
-
-
A New Placodont from the Late Triassic of China5 years ago in Chinleana
-
Posted: July 22, 2018 at 03:03PM6 years ago in Field Notes
-
Bryophyte Herbarium Survey7 years ago in Moss Plants and More
-
Harnessing innate immunity to cure HIV8 years ago in Rule of 6ix
-
WE MOVED!8 years ago in Games with Words
-
-
-
-
post doc job opportunity on ribosome biochemistry!9 years ago in Protein Evolution and Other Musings
-
Growing the kidney: re-blogged from Science Bitez9 years ago in The View from a Microbiologist
-
Blogging Microbes- Communicating Microbiology to Netizens10 years ago in Memoirs of a Defective Brain
-
-
-
The Lure of the Obscure? Guest Post by Frank Stahl12 years ago in Sex, Genes & Evolution
-
-
Lab Rat Moving House13 years ago in Life of a Lab Rat
-
Goodbye FoS, thanks for all the laughs13 years ago in Disease Prone
-
-
Slideshow of NASA's Stardust-NExT Mission Comet Tempel 1 Flyby13 years ago in The Large Picture Blog
-
in The Biology Files
The Who, What, When, Where and Why of Chemistry
Chemistry is not a world unto itself. It is woven firmly into the fabric of the rest of the world, and various fields, from literature to archeology, thread their way through the chemist's text.
Half-awake, half-life
I had a moderate allergic reaction to peanuts last night. I took diphenhydramine (Benadryl) and the hives had subsided by this morning. Lecturing on perturbation theory was more challenging. I felt like I was walking in a fog. Which got me to wondering, just what was the half-life of Benadryl? Benadryl has a relatively long half-life, between 8 and 10 hours. A typical 50 mg dose leads to a peak blood level of around 80 nanograms/ml. Most people feel drowsy at blood levels around 30 nanograms/ml. Assuming first order kinetics apply to the breakdown/elimination of Benadryl, a 30 nanogram/ml is not unlikely 10 to 15 hours later. Which would certainly explain my fogged state this morning! But not so foggy as to be unable to work the kinetics....
8 comments:
Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="http://www.fieldofscience.com/">FoS</a> = FoS
Subscribe to:
Post Comments (Atom)
Interesting. This explains why summer passed me by in a haze of diphenhydramine!
ReplyDeleteFor some reason I thought the half life was relatively rapid and I was just responding strangely.
I had to stop taking benadryl for allergies unless I was planning on staying home for a day -- it just makes it too hard to work!
ReplyDeleteI'm one of the lucky people who do not get sleepy from antihistamines. Any idea why it doesn't affect me? I guess the real question should be why does it put you in a fog?
ReplyDeleteBy the way, the abbreviation for liter is upper case, i.e. L. Thus the abbreviation for milliliter is mL not ml. This became official back in the 1970s and published in the Federal Register which has the final say since liter is a uniquely American unit.
That is false. There’s no difference in meaning between liter and litre nor, for that matter, between meter and metre.
DeleteDennis
DeleteI believe he or she meant only that the abbreviation the op used should have been typed as mL, rather than ml. They weren't disputing Europe's spelling as litre vs US's liter.
If you take it enough you should build up a tolerance. Take often in the evening and the fog will subside by the time you awake in the morning...
ReplyDeleteYou're a real expert on everything, aren't you? Do you know how annoying that is? If you want to feel good about yourself, stop pretending to be superior and start being good/generous to other ppl.
DeleteJust a note on the mechanism of brain fog. Diphenhydramine is a non-selective histamine receptor antagonist - it blocks histamine receptors. Newer second-generation antihistamines, in contrast to diphenhydramine, do not easily pass the 'blood brain barrier' (BBB). The BBB is created by astrocyte (support cells in the brain that are not actually neurons, or brain cells that can fire in the same way that neurons can) foot processes that line the blood vessels of the brain, enabling selectivity of what actually enters the tissue of the brain. After crossing the BBB, diphenhydramine blocks histamine receptors, most importantly those in the cerebral cortex. Histamine is actually produced in the hypothalamus and released in the cortex as one of the many overlapping systems that maintains wakefulness. So, blockade of these receptors makes you feel sleepy.
ReplyDeleteAnother reason is that diphenhydramine also blocks some types of acetylcholine receptors, less powerfully than blocking histamine receptors. Nonetheless, in high doses, diphenhydramine blocks these receptors, again within the cortex, resulting in decreased 'cortical activation'. This will result in some cognitive impairment and, possibly, some reduction in memory formation. Several brain regions that maintain wakefulness depend on acetylcholine. The anticholinergic action of diphenhydramine is also responsible for some degree of inhibition of saliva release and a dry mouth.