At the Cleveland Clinic, which has been unusually proactive in dealing with shortages and allowed a reporter access to personnel making decisions about them, one scarce leukemia drug, daunorubicin, was saved for patients in clinical trials, to avoid making the results invalid by substituting another drug. But when a different drug, methotrexate, was in short supply, pediatricians stopped giving it to all patients who required high doses, including those in research trials. “We didn’t want to say just because you’re on a clinical trial you get an advantage,” Dr. Rabi Hanna said.

Patients’ weight can be taken into account. Obese patients, who researchers found needed up to three times the amount of an antibiotic before surgery than average-size patients, were given only the standard dose at the Cleveland hospital until a shortage subsided.

Some institutions prioritize based on age; others do not. Marc Earl, a Cleveland Clinic pharmacist, said children were not favored over adults during chemotherapy shortages. But at other hospitals, they have been, because of their potentially longer life span or because they sometimes require smaller doses of a drug.

“We do play the pediatric card for sure,” said Alix Dabb, a pharmacy specialist in pediatric oncology at Johns Hopkins Hospital. Dr. Kenneth Cohen, director of pediatric neuro-oncology there, and his colleagues were close to being forced into making “very, very hard decisions,” he said. “The discussions became, ‘Why are two kids more important than one adult?’”

Ning-Tsu Kuo, a pharmacist at the Cleveland hospital’s home infusion pharmacy, said children came first during shortages of nutritional products such as intravenous vitamins and fats for patients who cannot absorb food. The logic was that adults have more reserve. But after one man pleaded not to have his dose cut, Dr. Kuo agreed. When reprimanded by colleagues, she recalled saying: “Patients are not equally the same. You need to look case by case.”

‘Downright Scary’

Such decisions have real consequences. For some shortages, doctors can soon see the effects of rationing, such as increased pain or nausea when drugs typically used to control symptoms are withheld, or patients who have to undergo invasive surgery to control cancer when anti-tumor medications are delayed.

Studies have associated alternative treatments during drug shortages with higher rates of medication errors, side effects, disease progression and deaths. For example, children with Hodgkin’s lymphoma who received a substitute to the preferred drug had a higher rate of relapse, researchers found, and adults with a genetic disorder called Fabry disease had decreased kidney function when their medication was cut by two-thirds. One alternative guideline adopted during a shortage of intravenous nitroglycerin “was downright scary from a clinical perspective,” according to Dr. Nicole Lurie, a senior federal health official.