Fairfax County Sheriff James D. Swinson said yesterday that a prisoner whose death is being investigated by prosecutors was denied prescribed medication while in jail and was given sedatives for which proper records were not kept.

The sheriff, who runs the jail, also disclosed in an interview that Donald L. Ferguson, a 28-year-old construction worker who died in December after being held in the jail, was put in handcuffs and leg irons and placed for two days in a small padded cell where he lay amid spilled food and his own urine. Ferguson, arrested for his failure to pay a $50 find, was suffering from alcohol withdrawal, Swinson said.

"Going through the door of my jail is not a ticket to eternal life," said Swinson whose jail operations have caused much controversy. "People have died there before and people will die there againt. It doesn't make a rat's ass if I'm sheriff or if you're sheriff."

Ferguson was the third inmate in the past six months to die after confinement in the jail. Is death has evoked angry protests from Fairfax County's largest black community, Gum Springs, where Ferguson grew up.

Supervisor Warren I. Cikins (D-Mount Vernon), who raised the question of Ferguson's death before the County Board of Supervisors, said yesterday the incident points to serious failings in the county's justice system.

Swinson said Ferguson began showing symptoms of alcohol withdrawal on Monday morning, Dec. 4. He banged his head against his jail cell and had to be transferred to the padded cell, the sheriff said.

After a commitment hearing, Ferguson was sent on Dec. 6 to Western State Hospital in Staunton, Va., where he died two days later of Kidney failure.

Commonwealth's Attorney Rovert F. Horan Jr. who has been investigating Ferguson's death, said yesterday that the prisoner arrived at the mental institution looking "extremely dirty, undernourished and dehydrated."

Horan told the supervisors on Monday there are still questions to be answered about whether Ferguson received any food or water while in the padded cell and why a jail medic did not follow jail regulations for giving medication.

In an interview yesterday, Swinson said he did not know why Ferguson was not given proper medication, but said the prisoner's death has been "blown out of proportion." "I am going to take whatever steps I deem appropriate to prevent a reoccurrance of it," he said.

Ferguson had been seen by jail physician Dr. David M. Abbott, Swinson said, and the doctor prescribed an injection of a sedative called Valium and an injection of vitamin B-1. The doctor also said that restraints should be placed on Ferguson's hand and feet, the sheriff said.

Swinson said that a medic gave Ferguson an extra injection of Valim without recording the injection in the prisoner's health records, as required by jail regulations.

The sheriff also said that the medic did not give Gerguson the vitamin injection that had been prescribed. The vitamin, according to medical authorities, is often prescribed to patients suffering from alcohol withdrawal as a treatment for hallucinations and trembling.

Swinson said yesterday that the medic's actions were "wrong," but that no decision has been made about possible discipline.

Swinson said yesterday that part of the blame for Ferguson's death rested on the lack of an alcohol detoxification center in Northern Virginia. He said his jail gives the best treatment possible for alcohol withdrawal what a jail can provide.

"When you don't perform a miracle," Swinson said, "then you are called a damn rascal."

Horan said yesterday he will make a complete report on Ferguson's death to the supervisors at their Monday meeting.