ABSTRACT
Introduction
Method
Results and discussion
Author: R. D. BUDD
Pages: 27 to 30
Creation Date: 1981/01/01
A survey has been made of the drugs found in the analysis of 10,000 urine specimens collected from Los Angeles County methadone maintenance patients during the summer of 1979. The results of this survey have been compared with the results of a survey carried out in the same County in 1975, indicating a marked decrease in use of drugs monitored in urine specimens. Some methodological limitations of data used in this study have also been discussed.
There has been considerable controversy about the effectiveness of maintenance programmes. It is therefore important to determine whether they actually have been able to reduce abuse of opiates, especially heroin, in a given population.
In 1975 the laboratory of the Rancho Los Amigos Hospital began testing urine samples for drugs from methadone maintenance patients in Los Angeles County.
In the autumn of the same year a survey of the extent of drug use within the methadone maintenance population was carried out [ 1] . Four years later a second survey was carried out. Comparison of the two surveys provides one means of assessing the effectiveness of the methadone maintenance programmes.
The population studied consisted of persons enrolled in Los Angeles County methadone maintenance programmes.
Some patients were enrolled in compliance with legal or probationary conditions, but most of the patients were there voluntarily. Patients could be terminated from the programme for violation of methadone regulations, such as continued drug abuse.
Urine samples were collected at the individual methadone clinics under the supervision of clinic personnel. By state law, all persons enrolled are required to be tested at least weekly on a random time, short-notice basis, for methadone and morphine, and monthly for barbiturates and amphetamines. In practice, all patients were tested weekly for all drugs.
The urine samples were kept under refrigeration from the time of collection through analysis except while being transported to the laboratory. Results of the analyses were reported back to the clinics within 96 hours of the time of specimen collection.
All urine samples were screened for the presence of opiates and barbiturates by radioimmunoassay [ 2] [ 3] and for the presence of methadone and amphetamines by Enzyme Multiplied Immunoassay Technique (EMIT) [ 4] [ 5] . All samples found positive for opiates, barbiturates and amphetamines, or negative for methadone, were confirmed by both gas chromatography and thin layer chromatography [ 2] [ 3] [ 5] [ 6] [ 7] . In the analysis strict quality control procedures were employed.
Ten thousand urine samples were collected in May, June and July 1979 from the Los Angeles County methadone maintenance population and tested for the presence of opiates (codeine and morphine), barbiturates (allylbarbital, amobarbital, butabarbital, pentobarbital, phenobarbital and secobarbital), amphetamines (amphetamine and methamphetamine), methadone and, when necessary, the primary metabolite of methadone.
The results of this 1979 survey and the earlier 1975 survey [ 1] are summarized in tables 1 and 2. The results of the 1975 survey have been extrapolated to 10,000 samples.
The results indicate that while there has been little change in methadone usage, there has been a substantial decrease in the use of other drugs after four years. The percentage of drugs other than methadone identified in urine dropped from 23.0 per cent to 13.4 per cent (table 1) and the total number of drugs found dropped by more than one half (table 2). All of the drugs, other than methadone, were found less frequently than they were in 1975 (see table 2).
Number of samples |
|||
---|---|---|---|
Result of analysis |
1975 |
1979 |
|
Methadone
|
|||
Positive for methadone
|
9633 | 9666 | |
Positive for methadone metabolite only (negative for methadone)
|
141 | 219 | |
Negative for methadone and its metabolite
|
226 | 115 | |
Drugs other than methadone
|
|||
Positive for drugs other than methadone
|
3362 | 1561 | |
Positive for opiates
|
2487 | 1122 | |
Positive for barbiturates
|
550 | 296 | |
Positive for amphetamines
|
325 | 143 |
Number of samples |
|||
---|---|---|---|
Drug |
1975 |
1979 |
Percentage decrease |
Morphine
|
1715 | 776 | 54.8 |
Codeine
|
772 | 346 | 55.2 |
Phenobarbital
|
354 | 210 | 40.7 |
Amphetamine
|
228 | 108 | 52.6 |
Methamphetamine
|
97 | 35 | 63.9 |
Amobarbital
|
44 | 29 | 34.1 |
secobarbital
|
74 | 25 | 66.2 |
Allylbarbital
|
19 | 16 | 15.8 |
Pentobarbital
|
34 | 13 | 61.8 |
Butabarbital
|
25 | 3 | 88.0 |
Total
|
3362 | 1561 | 53.6 |
The results also indicate that there has been no significant change in the preferred drugs of abuse (see tables 1 and 2). The opiates (codeine and morphine) are still by far the most frequently found drugs.
The results would appear to indicate that Los Angeles County methadone maintenance programmes have achieved some success in reducing use of drugs other than methadone among their populations. However, several factors must be considered in interpreting these results and their significance.
First, a sample in this study does not represent a person. The 1979 survey, for example, includes about 13 samples from each person in the methadon maintenance programmes. The samples were collected in a similar manner in 1975.
Secondly, metabolism may have affected the results of the surveys. Some of the morphine positives may be due to heroin or codeine metabolism; very few were probably actually due to morphine use itself. Some of the amphetamine positives may be due to methamphetamine metabolism. However, although many of the morphine and amphetamine positives may be due to metabolism of other drugs, this factor was probably present in the studies of both years.
Some of the drugs used were obtained on prescription. In a survey based on urine testing it was not possible to separate prescription use from non-prescription use. There is no reason, though, to suspect that prescription drug use would differ substantially over the four years.
While the results indicate a substantial decrease in drug use of tested drugs other than methadone over the four years, they may also indicate a switch from the drugs that are detected by our laboratory to drugs for which we do not test.
We do not have the information to substantiate or refute this notion. We also have no way to compare the frequency of use of other drugs in the two periods studied.
Finally, since methadone maintenance patients who continue to abuse drugs can be removed from the programme, the decrease in drug use found in the 1979 survey may indicate only a weeding out from the programme of persons who continue to abuse drugs.
N. C. Jain and others. "Patterns of drug use among methadone maintenance patients in Los Angeles County", Bulletin on Narcotics . vol. 29, No. 2 (1977), pp. 45-53.
002N. C. Jain and others, "Mass screening and confirmation of codeine and morphine in urine by radioimmunoassay-GLC", Journal of Pharmaceutical Sciences. vol. 66, 1977, pp. 66-69.
003N. C. Jain and others, "Mass screening and confirmation of barbiturates in urine by RIA/gas chromatograph", Clinical Toxicology . vol. 2, 1976, pp. 221-233.
004EMIT Methadone Assay, Enzyme Immunoassay for rapid analysis of methadone in urine, Syva Corp., Palo Alto. California.
005N. C. Jain and others, "Mass screening and confirmation of seven sympathomimetic amine drugs by EMIT-gas chromatograph", Journal of Analytical Toxicology . vol. 1. 1977. pp. 233-235.
006R. D. Budd, D. F. Mathis and W. J. Leung, "Screening and confirmation of opiates by thin layer chromatography", Clinical Toxicology . vol. 16, No. 1 (1980), pp. 61-66.
007R. D. Budd and W. J. Leung, "TLC confirmation of methadone and its- primary metabolite in urin". Clinical Toxicology. vol. 16, No. 1 (1980), pp. 55-59.