The number of heroin overdoses is increasing across the U.S. at an alarming rate, but many of the related deaths are preventable, according to a new report. With proper diagnosis and treatment that begins close to an hour after an overdose, a majority of patients should survive, says Karl Sporer, M.D., UC San Francisco assistant professor of medicine and author of the analysis, which appears in the April 6 issue of Annals of Internal Medicine.
He also emphasizes that overdose preventive measures like methadone maintenance, in which heroin users receive a synthetic narcotic drug to help treat their addiction, have proved effective, and increasing the availability of this type of program could reduce the number of deaths.
A specialist in emergency medicine who treats patients at the UCSF-affiliated San Francisco General Hospital Medical Center, Sporer began researching the medical literature a year ago for all current information on acute heroin overdoses when he found no comprehensive update was available.
The Annals article covers the pharmacology of heroin, incidence of fatal overdoses, diagnosis, treatment, complications, and prevention programs. "One surprise was the documentation of the dramatic activity of heroin in the body compared to morphine and other opiates," he says. "Heroin is more soluble in the fat cells so it crosses the blood-brain barrier within 15-20 seconds, rapidly achieving a high level in the brain and central nervous system, which accounts for both the 'rush' experienced by users and the toxicity."
Heroin produces its effects by acting on key receptors in the central nervous system that are linked to a slowed breathing rate, feelings of euphoria, and physical dependence on the drug, he adds.
In the U.S., heroin-related emergency department visits have doubled from 33,900 in 1990 to 70,500 in 1996. Of persons who inject heroin, the average annual death rate is two percent.
The clinical criteria for diagnosis of a heroin overdose is severe coma in combination with factors such as severely depressed breathing, extremely constricted pupils, or circumstantial evidence of drug use. There has been varying medical opinion about immediate use of the overdose antidote, naloxone, in all suspected cases, but current guidelines suggest its use only if the patient is having critical breathing problems, according to Sporer.
Other overdose preventive strategies that have proved to be effective are education programs for heroin users that focus on their peak periods of vulnerability for use--such as the first year after discontinuing addiction treatment and the first two weeks after release from incarceration--and education programs that encourage use of the 911 emergency system.
Findings reported in the Annals article include:
- With intravenous use, 68 percent of heroin is absorbed into the brain
compared to less than five percent of morphine.
- Heroin is absorbed rapidly through all routes of administration. It
peaks in the blood serum in less than one minute with intravenous use. Through
the nasal passages or injection in the muscular tissue, the peak occurs in 3-5
minutes. With injection in the subcutaneous tissue beneath the skin, the peak
occurs in 5-10 minutes.
- The route of administration strongly affects heroin's potential to
cause death or overdose. Most fatal and non-fatal overdoses are linked to
intravenous administration.
- Most deaths occur among heroin users who are in their late 20s or
early 30s, have used the drug for 5-10 years, and have significant dependence.
- Multiple drug use is common in heroin-related deaths, with significant
levels of alcohol in 29 to 75 percent of cases.
- In most cases of death, medical help was not sought or sought too
late. An ambulance was called in about 14 percent of overdose cases, with fear
of police involvement as the major reason for not calling 911 for help.
- The most common complications of heroin overdose treatment are pulmonary edema (fluid in the lungs) and pneumonia.
Journal
Annals of Internal Medicine