One day in 1974, Lou Reed showed up at my door looking like death warmed over, and taught me how to save my own life.

“Let’s go, McCormack, get dressed,” he ordered, scanning my cluttered apartment through his omnipresent skull-socket shades.

“I’ve got a cab waiting downstairs, and I’m taking you to my doctor.”

“It’s still fucking dark out, Lou. What time is it anyway?”

“Don’t worry about it. This guy gets in early. And he can cure anything—including cirrhosis—as long as you’re honest with him about your habits.”

“But I’m feeling better. The pain went away,” I lied. “Anyway, you know I don’t believe in doctors. They’re the diagnosticians of doom, man—only useful for scoring drugs or getting declared dead.”

There was no point arguing with him; he wasn’t even listening.

“Gotta do something about this hair,” he said, pulling at an unruly clump of curls as we stomped down the stairs, probably waking up the whole building. “Maybe get one of those nigger combs.”

“You mean an Afro pick?”

“Yeah, a nigger comb,” said Lou, who never stopped raving to me about the superiority of black music and musicians.

Out on the street, giving me the head-down “perp push” into the cab, as though it were a patrol car, he directed the driver to 78th Street and Park Avenue.

The doctor turned out to be the notorious society and show-business croaker Robert Freymann, supposedly the original “Dr. Feelgood.” His past patients were rumored to range from J.F.K. to the Beatles, and a veritable Who’s Who of prominent speed freaks still gathered in his office at an ungodly hour for his magic vitamins. (“Day or night he’ll be there, any time at all,” the Beatles sang in their musical tribute “Doctor Robert,” which Paul McCartney admitted was inspired by the doctor “who kept New York high.”)

This particular morning, though, Lou made an honest physician of Freymann, who took an X-ray and disabused me of the notion that I was at death’s door.

“Your liver looks O.K., but your bowel is slightly distended,” he informed me in his guttural German accent. “You better go a little easy on the drinking.”

When I asked him how much I owed him, he said that Lou had already taken care of it.

All these years later, I would have loved to e-mail Lou on the occasion of his own life-saving, though temporary, medical procedure in May of last year, saying something like, “Mazel tov on the new liver, man.” After all, the 12-step group in which both Lou and I eventually got clean and sober recommends getting in touch with and making amends to those one wronged under the influence. The only thing that stopped me was the memory of a long ago, small but haunting betrayal of my friend’s trust that still leaves me shamefaced to this day.

I woke up that day in 1975 on a black-leather sofa with my head feeling like the inside of Ginger Baker’s drum set and my red eyes trying to focus on an elegant glass coffee table, on top of which was a very strange still life: a bottle of prescription pills, a circular silver dish with 12 disposable hypodermic needles neatly arranged along its edges in a sort of speed-freakishly compulsive sunbeam pattern, and a row of test tubes filled with water, little white pills dissolving in milky bubbles within each one.

Lowering my gaze to the zebra-skin rug on the floor, I found a pale, delicate ankle, a hairless shin, a slender calf, and a rather bony knee, which quickly, coyly crossed, as I glanced up, over another knee under a blue silk kimono.