One in an occasional series by caregivers on some aspect of care.

Santiago and his cheery "Doctora, que pasa?" will remain forever etched in my memory.

At 38, cherubic and feisty, he was the first kidney-transplant recipient I cared for as a nephrology trainee, and one who taught me about a big gap in Medicare drug coverage.

I bonded with him over several cups of soulless coffee at the corner deli that is central to medical training at Weill Cornell Medical Center in New York. Both of us were new to the world of kidney transplantation: he as a patient, I as a doctor, and we bonded as neophytes. Fortunately, his new kidney worked beautifully, and he sailed through the first crucial months after the transplant.

When I noted how well he looked a year later, he winked conspiratorially. "You know what the best part is, Doctora? When I was on dialysis, I gave up pizza for good to stay healthy. Now I can eat pizza without cringing. I can't believe I got a second shot at life!"

I moved on later that year, taking with me fond memories of many grateful patients, including my amigo in his pizza reverie.

So it was with dismay that I spotted Santiago stepping into the hospital's dialysis unit when I paid a visit to New York.

His eyes lit up when he recognized me, but it was evident the zest was gone. Not knowing where to start, I blurted out: "What happened?"

Over another cup of tasteless coffee, Santiago filled me in. "Doctora, this cup of coffee is what my life tastes like now."

Fighting tears, he went on. "I did very well for three years until my insurance was dropped automatically, and I could not afford my medications. I tried really hard to find a job to get insurance, but it's New York City, you know . . . . I ended up losing the transplant and now I am back on dialysis." He trailed off, leaving an aching silence for which I had no words of comfort.

That day, my memory floated back to my graduation ceremony at medical school, reliving the moment I took the Hippocratic Oath and vowed to affirm its guiding principle, "Primum non nocere" - "First, do no harm." In Santiago's case, this cardinal principle was trampled by Medicare's outdated coverage rules.

Kidney transplantation was risky when Boston surgeon Joseph Murray did the first one in 1954. Today it's safe and routine and, when feasible, represents the best choice for end-stage kidney disease. But a transplant requires a lifetime of immunosuppressive drugs to keep the body from rejecting the organ.

In 1993, Medicare began covering 80 percent of drug costs for three years after kidney transplantation. And while this was later extended to lifetime coverage for disabled patients or those over 65, a large number of younger kidney-transplant recipients find their drug benefits cut off at 36 months.

Patients like Santiago are not just endangering their kidneys; they are risking their lives. Study after study has shown that the transition from a failed transplant to dialysis is the most hazardous point in a patient's life.

Equally staggering is how Medicare will pick up the tab, down to the last penny, for all the extra care to re-dialyze these sickest of patients.

The final outrage is that these patients are branded "noncompliant" for being unable to stay on their prescriptions for reasons beyond their control, greatly diminishing their prospects for another transplant.

We doctors feel helpless. We witness life-changing breakthroughs followed by wrenching reversals.

It's not as if add-ons to Medicare aren't made all the time. Drug firms recently won a two-year delay in Medicare price restraints for a class of drugs including Sensipar, used widely in dialysis patients. This decision is projected to cost Medicare $500 million over two years.

Curiously, this came on the heels of a landmark trial, reported in the New England Journal of Medicine, that questioned the benefits of Sensipar.

It stuns me that we will pay mountains of cash for a questionable treatment while allowing patients like Santiago to lose their kidneys, waste precious donor organs, and die.

The Congressional Budget Office estimates the cost of indefinite coverage for kidney transplant patients at $600 million over 10 years. And we have indisputable evidence that transplants are safe, effective, and cheaper than dialysis. (The average cost of dialysis per patient is $86,000 per year, compared with $125,000 for the year of transplantation and $25,000 a year thereafter.)

The Affordable Care Act offers a glimmer of hope by covering more people. But we don't know if the new plans will offer drug coverage after transplant.

Doing that is clearly the most cost-effective and humane thing to do. But beyond that, we need to do the right thing for these patients and those who stand with them; to do right by the deceased donors, who offered the precious gift of life; and to do right by the donors' grieving families, who rose above human emotions to throw someone a lifeline.

The last I knew, Santiago remained on dialysis awaiting a second kidney transplant. I hope, for his sake and others', that next time around he will be supported by the efforts of Sen. Richard Durbin (D., Ill.) and Rep. Michael Burgess (R., Texas), who, like legislators in at least eight Congresses before them, have introduced a bill to change this situation.

These recipients cherish the chance to live life, get pregnant against the odds, celebrate birthdays, cuddle grandchildren.

They should be able to enjoy these things without fear that it all can be taken away. Above all, we owe them the joy of being able to indulge in an occasional slice of pizza.

Janani Rangaswami is a kidney doctor in Chestnut Hill at Delaware Valley Nephrology & Hypertension Associates, which is affiliated with Einstein Medical Center. She asks that, if you know of a transplant patient who lost drug coverage, write to her at nephrologymd1@gmail.com.