It’s just a little decimal point

Here’s a scary error, reported by Abel Pharmboy:

David Douglas of Reuters Health reported last Friday on the publication of a clinical trial revealing that a one-week trial of Benadryl (diphenhydramine HCl) was superior to Clarinex (desloratadine) in managing symptoms of moderate-to-severe allergic rhinitis, or hay fever. The article was published in the April 2006 issue of Annals of Allergy, Asthma & Immunology (2006;96:606-614)

You can read the results here but Douglas misprinted the Benadryl dose as 500 mg! three times daily. The actual dose, 50 mg, t.i.d., is already high enough to make one so drowsy as to not really care about one’s hay fever. (Somnolence was reported in 22.1% of pts on Benadryl as compared with 4.5% for Claritin, and 3.4% for placebo).

At 500 mg (twenty, 25 mg tabs or capsules) even taken once a day will cause disturbing hallucinations due to the central anticholinergic effects of this drug. I fear that some readers of the Reuters story who are really suffering with allergies might try to take the misprinted dose. (Disclaimer: DO NOT attempt taking high doses of Benadryl/diphenhydramine for the purpose of recreational hallucinations; it can be fatal, particularly when taken with other CNS depressants. Diphenhydramine alone can cause paradoxical CNS stimulation, seizures, and death in infants and should not be used in children under age two).

Someone could die if they try to take ten times the maximum recommended dose of Benadryl. Nice pickup by the Pharmboy. He also has more on this.

By Orac

Orac is the nom de blog of a humble surgeon/scientist who has an ego just big enough to delude himself that someone, somewhere might actually give a rodent's posterior about his copious verbal meanderings, but just barely small enough to admit to himself that few probably will. That surgeon is otherwise known as David Gorski.

That this particular surgeon has chosen his nom de blog based on a rather cranky and arrogant computer shaped like a clear box of blinking lights that he originally encountered when he became a fan of a 35 year old British SF television show whose special effects were renowned for their BBC/Doctor Who-style low budget look, but whose stories nonetheless resulted in some of the best, most innovative science fiction ever televised, should tell you nearly all that you need to know about Orac. (That, and the length of the preceding sentence.)

DISCLAIMER:: The various written meanderings here are the opinions of Orac and Orac alone, written on his own time. They should never be construed as representing the opinions of any other person or entity, especially Orac's cancer center, department of surgery, medical school, or university. Also note that Orac is nonpartisan; he is more than willing to criticize the statements of anyone, regardless of of political leanings, if that anyone advocates pseudoscience or quackery. Finally, medical commentary is not to be construed in any way as medical advice.

To contact Orac: [email protected]

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