Natural doesn't always equal harmless

I couldn't resist. I touched her arm lightly when I asked how I could help her. I think that she liked that. Her eyes twinkled as she smiled at me. "My memory," she said, "It's foggy."

"What are you taking?"

"No, I meant prescription drugs." It's true that plenty of people who smoked dope when they were 20-somethings in the 1960s are still doing it in 2012. When I counsel older patients on their prescription drugs, however, I rarely consider that they may be using recreational drugs.

"I do not take prescriptions. I want only natural herbs. My friend told me that something called Gingle could help with my fog problem."

"Ginkgo," I said. "It's supposed to help with memory. At least that's what Varro Tyler claimed, and he was the most famous pharmacognosy expert of modern times." I had to explain what pharmacognosy is.

"It's natural?"

"Yes, it is natural."

"Good, I want a bottle." She looked at me. "It will be okay with my A-fib?"

Hang on, Sloopy. "Are you taking a blood-thinner?"

"Just a tiny pill. It's natural. I don't take drugs."

"I don't think you want to take ginkgo," I said, "It can cause bleeding, and you're already on a blood thinner."

"But why? If it's just an herb, how can it cause bleeding?"

"I don't know how it causes bleeding. It's in Varro Tyler's book, and we can trust him. No ginkgo for you. I'm sorry."