Originally Posted by wasakat
There are a lot of worming products on the market and many of us tend to balk at using them because they usually have a disclaimer stating not to consume eggs for 14 days after administering the final dose. Well, crums! Who wants to chuck out beautiful eggs for 24 days? (First dose, followed by a final dose 10 days later). I just picked up a bottle of Wazine - a very safe and highly effective anti-wormer - and was basically resigned to tossing out a huge number of eggs. Then, I did a little research, and I thought I would share what I found out.
The active ingredient in Wazine is piperazine. Among other things, piperazine is used to treat intestinal parasitic infections in chickens, pigs, dogs, and HUMANS. Dosage for humans is as follows: 6g taken orally for 1 day followed 10 days later by a second 6g dose for adults. For children 8 to 14 years old, the dosage is reduced to 4 g. For children 2 to 8, the dosage is 2 grams. (http://www.mayoclinic.org/drugs-supplements/piperazine-oral-route/proper-use/drg-20065522
When given to laying hens at a dosage of 300mg/kg body weight, piperazine was found in the eggs at a highest concentration of 0.8mg twenty-four hours after the hen was medicated, and then at 0.2mg ninety-six hours after the hen was medicated (http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=24898556&viewopt=Deposited
.) For folks who don't remember, there are 1000 mg in a single gram, so the smallest dosage used to treat a 2-year-old is 2000 mg. Given this information, I wondered why the product warns to withdraw eggs for 14 days following the final dose when the most that has been found in an egg is just 0.8 mg ( less than 1/2000th of the dose used for a two-year-old).
Well, those withdrawal guidelines were enacted by the FDA in 1996, and they were pretty arbitrary. The guidelines were meant to ensure that people wouldn't be exposed to the drug at levels higher than a dose "13,000 times lower than the therapeutic dose well tolerated by humans." (http://www.fda.gov/downloads/AnimalVeterinary/Products/ApprovedAnimalDrugProducts/FOIADrugSummaries/ucm049524.pdf
Shenanigans! I have my own conspiracy theories as to why the FDA created those withdrawal recommendations back in 1996, but I won't punish you all with them. I will, however, be eating the eggs that my gals lay after I dose them with Wazine, and I won't be worrying about poisoning myself because even if I gorge on six eggs the very next day, I'll have only ingested 6.4 mg (or 0.1 % of a therapeutic dose of a drug used to treat parasitic infections in humans). If I were pregnant or breast-feeding, I might err on the side of caution, but I feel confident that a 0.1% dose isn't going to hurt me or anyone else in my family.