Boletín Asociación Médica de PR - Vol. 89 7-8-9, Páginas 150-151

Alcohol and/or Cocaine Effect on Driving

Sidney Kaye, Ph. D., M. Sc., D-ABCC
Professor Emeritus., School of Medicine, University of Puerto Rico

Man since his early beginning has been seeking a "mood modifier" to block out his frustrations, fears, hunger, fatigue and other miseries to temporarily escape reality.

Today that fist of miseries includes insecurity, stress, sadness, bitter memories, boredom, anxieties, loneliness etc.

Alcohol easily fitted the prescription and has become a very serious public health problem in being a prerequisite to several serious diseases1, and fatal accidents. Especially sad is the preventable "Drunk Driving Problem".

In Puerto Rico, alcohol related fatalities started to be reported in 1968 based on the results of an autopsy and toxicology analysis. In 1976 a summation of 1968 to 1976 showed that an average of 64% of the cases were alcohol related2. Then a gradual decrease started to occur and today the alcohol related traffic fatalities are less than 50%, but who should be content with a 40% alcohol related avoidable traffic death statistic. This could be further decreased.

To further complicate the present situation, cocaine has now appeared to add to the problem, by itself and in combination with alcohol.

A brief update review of recent new developments is offered on Alcohol and/or Cocaine in Drug related Traffic fatalities.


ALCOHOL

  1. Drinking at least 3 oz of whiskey 40% or 12 oz of wine 10% or 30 oz of beer 4%can produce a residual blood alcohol concentration (BAC) of 0.05% in a person weighing about 154 lb (70 Kg)1.

  2. A post absorption equilibrium of blood alcohol 0.05% and urine alcohol 0.07% is the usual approximated ratio 1 hour or more after the last drink. Alcohol follows the water pattern1,3.

  3. Human blood alcohol is metabolized at the rate of about 0.015 - 0.020 % per hour which reduces the blood alcohol concentration (BAC) to zero in time1,3.

  4. Ethyl alcohol is a central nervous system depressant for every one even at low blood concentrations (BAC). One does not have to be obviously "drunk" to be "accident prone" and "under the influence" at least to some degree, and be unfit to properly operate a motor vehicle1.

  5. Although most countries of Europe, California and several other states have now lowered the BAC legal limit to 0.08%, and some have set a 0.05% limit, Puerto Rico and most of the U. S. still have the 0.10% legal limit. As the blood alcohol concentrations increases so does the severity of its effects increase because it is dose related1.

  6. Driver fatalities in single car crashes were at risk:

    7. 0.05 - 0.09% BAC range…………… 9x greater than at zero4;

    at or above 0.15% BAC……………. 300 to 600 x greater than at zero

    CNS depression (divided- attention and information processing tasks) may show impairment at 0.015% and increases with increasing BAC4.

  7. Investigators have not found an absolute BAC threshold below which there is no impairment of any kind. Certain skills important for driving are impaired at 0.01% to 0.02% BAC, the lowest levels that can be measured reliably by commonly used device5.  
  8. BAC legal limits of 0.15% were in effect before 1940. BAC legal limits of 0.10% were in effect in the 1970s in the United States and in Puerto Rico in relation to Driving while Under the Influence (DUI).  
  9. It has been rumored that cocaine as a stimulant will help to offset the drunkenness of alcohol. This is not true! A new compound coca ethylene is formed which now may help to sustain and prolong the combined behavioral effects of cocaine and alcohol. This needs to be further investigated, and be fully supported as to what extent. There is however no doubt that it can and does produce some psychologic and behavioral changes that can affect his safety6.

 

COCAINE
  1. As for cocaine there is no definite blood level set by law for Driving Under the Influence (DUI) of cocaine in the United States or Puerto Rico. It is usually reported as a "Drug Related" accident in some jurisdictions6.

  2. Cocaine (methyl benzoyl ecgonine) is one of the most powerful central nervous system (CNS) stimulants. It is for this anticipated CNS stimulation and "pleasure-feeling" that one easily becomes addicted to its use. Cocaine is not dose related for humans. Deaths can occur at low levels and may not always occur at higher levels. But all persons are effected to some degree to some of the symptoms even at low levels6.

  3. The use of cocaine can produce a euphoria and pleasurable feeling, stimulation, excitement, restlessness, agitation, hyperactivity, self confidence and a feeling as superman which could yield to risk taking and accident proneness. Dilated pupils could produce blurred vision, a sensitivity to light and difficulty in focussing6.

  4. An unpleasant after depression, fatigue and irritability can follow after the short duration of these symptoms and effects. This may call for reinforcement with more cocaine and the vicious cycle is continued.

  5. It is now recently established that the combined use of alcohol and cocaine produces a new compound coca ethylene, which appears to contribute additively to the psychologic effects of cocaine and behavior changes6.

  6. The 1/2 life of cocaine in blood is about 1 hour. It is rapidly metabolized to benzoyl ecgonine which may still be found in urine 2 days later. The 1/2 life of benzoyl ecgonine is about 6 hours. The 1/2 life of coca ethylene is about 100 minutes6.

It is difficult to interpret Blood Cocaine levels because:

  1. There is no specific law in Puerto Rico defining the effects and response to a specific blood level of cocaine on human behavior; and blood is not usually available for testing; except at autopsy.

  2. The intake of cocaine and behavioral response and lethal dose is not dose related6.

  3. Cocaine is metabolized rapidly and leaves the blood circulation, and is eliminated in urine.

  4. It is the blood level circulating (to the brain not the urine level) that affects human behavior.

  5. Cocaine (1/2 life) is rapidly removed from the blood and at death the blood levels may be very low and be still regarded as "Drug related" in some jurisdictions6.

  6. It is now known that cocaine blood levels can actually increase after death6. It is also known that if blood is stored without a 2% potassium fluoride preservative prior to analysis, the blood levels can be reduced6.

  7. The quantitative effects of coca ethylene on human behavior has not yet been fully studied and reported, but preliminary reports indicate psychologic response similar to cocaine6.

  8. Blood alcohol levels or cocaine levels in any case even if low can still be significant when evaluated together with the time in question, the place, the environment, the activity and all other related factors. Both alcohol and/or cocaine can produce some behavioral changes that could lead to accidents even at low levels; also when in depression or fatigued, or "superman" attitude, etc.


SUMMARY:

  1. Alcohol has been researched in reference to the "Drunk Driver" for more than 50 years. Many countries in Europe and elsewhere have set the legal acceptable blood alcohol level at 0.08% or 0.05%. There are some central nervous system and behavioral changes even at much lower concentrations1,2,3,4.

  2. Cocaine has not as yet been equally extensively researched as was alcohol for DUI. However it can produce a strong stimulation, hyperactivity, euphoria, delirium, pleasure and some of the other symptoms previously described above which makes it so powerfully addictive and desirable and also accident prone plus the after depression and fatigue that could also affect traffic safety.

  3. In spite of the fact that there is a paucity of information and publications on the incidence and effects of cocaine in blood on behavior and safety, however to some degree cocaine can produce in all persons at least some of the signs and symptoms described above.


CONCLUSION:

  1. Perhaps consideration of lowering the Puerto Rico DUI to 0.08% blood alcohol content might be a good idea in compliance with preponderance of scientific evidence and world support, and also in the hope of lowering our traffic fatalities.

  2. Perhaps consideration of the finding of small amounts of alcohol or cocaine in the blood could be considered "as drug related", because even a low amount has an effect otherwise in reality it would not be such a serious problem. The severity of the problem depends upon the situation: whether driving an automobile, involved in a crime or an accident, or otherwise sitting at home watching television and drinking a beer or whatever.


REFERENCE

(1) Kaye, Sidney, Editorial, Bol. Asoc. Med.de P.R. 87:39 1995.

(2) Kaye, Sidney, The Problem Drinker on Traffic Fatalities in Puerto Rico - 1976, Bol Asoc Med de PR 69: 364, 1977.

(3) Kaye, Sidney, Observations on the Determination of Ethyl Alcohol, Ph.D. Thesis, Med Coll. Of Virginia, 1955.

(4) Alcohol Research, Insurance Institute for Highway Safety, 1005 N. Glebe RD. Arlington, VA 22201,October 1993.

(5) Alcohol Alert, National Institute on Alcohol Abuse and Alcoholism. #25, PH 351, July 1994.

(6) Karch, Steven, Pathology of Drug Abuse, CRC Press, Boca Ratón, 1993.