A snapshot poll of GPs has found that some are more reluctant to prescribe pain relieving drugs to terminally ill patients, fearing an accidental overdose could lead to them being "another Shipman".
There are now fears this "Shipman effect" is harming patient care.
John, a widower whose alert brown eyes belie his 80 years, is choking back tears as he looks at a photograph of a pretty, slim woman in a blue suit, taken in the 1970s.
Shipman used morphine to kill patients
This is his wife, who died of lung cancer two years ago.
"My wife suffered in the last stages extreme pain," John recalls. "And when she asked to be relieved of it, we were told that she couldn't be given any more pain relief if it might hasten her death."
John's wife spent her final weeks at a nursing home, treated by a local GP.
"It was quite pitiful. She was so distressed. She said that she'd asked them several times to give her more medication, and they declined.
"And she said, 'they wouldn't treat an animal like this.' That will stay with me for the rest of my life."
John believes that the main reason why his wife was refused sufficient pain relief is what's become known as the Shipman effect.
Britain's worst serial killer, Greater Manchester GP Harold Shipman, murdered elderly patients with opioid drugs which are normally used legitimately to alleviate pain at the end of life.
As a result, some doctors are now reluctant to prescribe them. They fear that if a patient dies of an accidental overdose, they may be branded the new Shipman.
Central London GP Dr Laurence Gerlis has radically changed the way he works as a result of Shipman.
He no longer makes home visits. And he no longer carries or prescribes narcotics, such as diamorphine.
This means he can no longer treat patients who require such drugs, such as people with terminal cancer or acute heart attacks.
"It's about risk management," he says. "I want to be above suspicion in every possible way. Which means giving a poorer service to my patients, but taking myself out of harm's way."
But not everyone agrees that the Shipman effect is an issue.
The Royal College of General Practitioners believes that only a small minority of doctors have changed their practice as a result of the Shipman case.
Other experts argue that given the right training and careful record keeping, doctors should have nothing to fear.
Yet in a snapshot survey by the Small Practices Association, a quarter of the 200 members who responded said that they are now more nervous about prescribing narcotic drugs.
One in three no longer carry them in their medical bags.
One in three also fear that increasing regulation of the use and movement or narcotics - introduced in response to the Shipman Inquiry - will hinder their ability to treat terminally ill patients adequately.
New proposals unveiled last month by England's Chief Medical Officer mean that doctors will also have to prove their fitness to practise every five years.
Some believe this will cause further insecurity among the medical profession, as might any court case against a doctor who has hastened a patient's death through incompetence rather than malicious intent.
Any such case could be "a disaster for palliative medicine", warns Professor Karol Sikora, one of the country's leading cancer experts.
"It would mean that before any strong analgesic would be given in hospitals, in a hospice, in the community, people would think twice, because they could be accused of exactly the same thing."
After Shipman, patient safety has become a primary concern.
Yet it could mean that others like John may go through the agony of watching a loved one die in avoidable pain.
"It's a travesty," he says, "that so many people think everything's fine with our palliative care system."
The Shipman Effect is on BBC Radio 4 at 2000 BST on Tuesday August 8.