Tony,
Your point is well taken and I have learned my lesson. I had read another post about some guy making and drinking tea made from Oleander and what I had considered a "small" amount (1/3 or 1/4 cup) would be okay.
I have subsequently waited about a week and started on 1/4 teaspoon, three times a day, and have worked up to 1/2 teaspoon. I expect it to take a month to work up to the full tablespoon, three times a day.
Thanks for the advice (that I should have followed in the first place).
Don