A drug and alcohol evidence primer

Issue Vol. 12 No. 1 January 2010


From time to time, the admissibility of an individual's alcohol or drug consumption is pertinent to the case. This article discusses some of the circumstances in which alcohol and drug evidence arises in civil cases and related admissibility issues.

Admissibility issues

In Massachusetts, evidence of drug or alcohol use is permitted at trial under a wide variety of circumstances. As with all evidence, however, to introduce evidence of the use of drugs and/or alcohol, several criteria of admissibility must be met. First and foremost, the evidence must be relevant. It must have a "rational tendency to prove an issue in the case." Commonwealth v. Fayerweather, 406 Mass. 78, 83 (1989). Once you clear this hurdle, review your admissibility options.

Evidence of the effect of alcohol or drug consumption may come in various forms. Interestingly, a layperson may provide an opinion about the sobriety of another person. Commonwealth v. Orben, 53 Mass. App. Ct. 700, 704 (2002). The fact that the basis for the opinion is a telephone conversation with a defendant, rather than actual physical observation or a person-to-person conversation, goes to the weight and not to the admissibility of the testimony. Id. Witnesses may testify to the individual's conduct - e.g., "staggering" and "drunk." Murphy v. Moore, 314 Mass. 731 (1943). See also, Martin v. Florin, 273 Mass. 13 (1930) (allegedly intoxicated individual permitted to testify concerning the effects of alcohol on him). Doctors may testify to the smell (or lack thereof) of alcohol on the person's breath. Id; See also Commonwealth v. Orben, 53 Mass. App. Ct. 700 (2002) (police can testify as to state of apparent intoxication).

Evidence of a plaintiff's drug or alcohol use also can be admitted into evidence through a plaintiff's medical records. In Commonwealth v. Beatty, 73 Mass. App. Ct. 1125 (2009), the court found a portion of the defendant's medical records - which indicated the defendant admitted "he was intoxicated and does not recall any events" - admissible pursuant to G.L. c. 233, §79. That case involved prosecution for operating under the influence of alcohol. The defendant attempted to preclude the admission of the relevant statement on the grounds that it did not "relate to [his] treatment and medical history" as the statute required and because it referenced "the question of liability." Id. at *1.

The court found, however, that where the defendant was seeking treatment for symptoms including headache and vomiting, information about his recent alcohol consumption was relevant to his medical care, and therefore, that his admission contained in the medical record was admissible. Id. Similarly, in Leonard v. Boston Elevated Railway, 234 Mass. 480 (1920), one of the plaintiff's medical records contained the words, "odor of alcohol on the breath," and the court ruled that these records were admissible. In so holding pursuant to G.L. c. 233, §79, the court stated:

… a record which relates directly and mainly to the treatment and medical history of the patient, should be admitted, even though incidentally the facts recorded may have some bearing on the question of liability.
Id., at 483.

The court also stated that it was unable, as a matter of law, to say that the words "odor of alcohol on the breath" could not relate to the plaintiff's medical history. Id., see also, Commonwealth v. Dube, 413 Mass. 570 (1992).

Medical records referencing otherwise relevant information, however, will be precluded where they are unreliable. In Commonwealth v. Johnson, for instance, the records themselves contained a disclaimer regarding the reliability of the subject test. 59 Mass. App. Ct. 164 (2003). The court held that the trial court's admission of the records regarding the test, therefore, was an error. Id.

Additionally, otherwise admissible records must, where appropriate, be redacted in part. Thus, a trial judge properly ordered deleted from the decedent's hospital records the fact that the decedent was apparently a recovering alcoholic because this evidence had no relevance to whether the decedent was intoxicated at the time of the accident. Commonwealth v. Shine, 25 Mass. App. Ct. 613 (1988).

Expert testimony concerning pharmacology

Experts are at times called to testify concerning the pharmacology of alcohol, and the expected effects of specific levels of alcohol on an individual, based on some explanation relating to consumption and "burn-off." Assuming the expert can be qualified, the following summarizes basic pharmacological principles the expert may be called upon to testify.

Alcohol, like all drugs, undergoes four scientific processes in the human body. These four processes take place at the same time until such time as all of the alcohol has been absorbed by the gastrointestinal tract and all of the alcohol has been metabolized. Vijay A. Ramchandani, Ph.D., Alcohol: Neurobiology and Pharmacology, www.projectmainstream.net/newsfiles/Alcohol_Neurobiology_and_Pharmacology.htm.

The first process is absorption. Absorption is the process by which alcohol is made available to the fluids of distribution of the body, such as blood, plasma, serum, etc. About 80 percent of orally consumed alcohol is absorbed from the small intestines with the rest absorbed from the stomach. On an empty stomach, more than half of the alcohol consumed will be absorbed within 15 minutes and a maximum blood level will occur in about 20 minutes, with 80 to 90 percent complete absorption occurring within 30 to 60 minutes. The rate of alcohol absorption depends on many factors, including the rate of consumption, how much is consumed, the alcohol's concentration, the presence of carbonation in the drinks, food in the stomach, and whether the person is taking any medications that can interfere with the gastrointestinal tract. Charles E. Becker, The Clinical Pharmacology of Alcohol, Calif. Med. V.113(3), pgs. 37-45 (Sept. 1970); David M. Benjamin, Ph.D., Understanding the Pharmacology of Ethanol, www.doctorbenjamin.com.

The second process is distribution. Once alcohol has been absorbed from the gastrointestinal tract into the blood, it is circulated to all areas of the body to which there is blood flow. This process takes time. Charles E. Becker, The Clinical Pharmacology of Alcohol.

The third process is metabolism. To ultimately remove alcohol from the body, it must first be inactivated. This is initiated by altering the alcohol's chemical structure into a substance that is more easily excreted by the body, and is often referred to as detoxification. Alcohol is metabolized in the liver by the enzyme dehydrogenase into acetaldehyde, which causes dilation of blood vessels. It is this dilation that is responsible for hangovers. Vijay A. Ramchandani, Ph.D., Alcohol: Neurobiology and Pharmacology.

The acetaldehyde is next metabolized by the enzyme aldehyde dehydrogenase into acetate, which is very similar to vinegar. Measurement of blood serum acetate levels may be an indicator of problem or chronic drinking. Charles E. Becker, The Clinical Pharmacology of Alcohol; Vijay A. Ramchandani, Ph.D., Alcohol: Neurobiology and Pharmacology.

Certain drugs can inhibit the aldehyde dehydrogenase enzyme responsible for the second step in metabolizing alcohol, and inhibition of this enzyme causes an increase in blood acetaldehyde levels. One of these drugs is antabuse, which is often used to treat alcoholics. People taking antabuse can become very sick from consuming even a small amount of alcohol. Other such drugs include chloral hydrate and oral anti-diabetic drugs such as Diabinese. David M. Benjamin, Ph.D., Understanding the Pharmacology of Ethanol.

The fourth and final process is excretion. The kidneys and lungs excrete only 5 to 10 percent of unmetabolized alcohol. The rest must be metabolized before excretion. Determination of the rate of alcohol excretion can be effectively measured once all of the alcohol in a person's gastrointestinal tract has been absorbed. Once this occurs, blood level determinations should show a decline with time. Alcohol's effect on a person is greater when his or her blood alcohol level is rising than when it is falling. In most people, the excretion rate ranges from about 0.01 to 0.025 percent per hour. Charles E. Becker, The Clinical Pharmacology of Alcohol.

Only air in the deepest portion of the lungs is in equilibrium with blood alcohol. As such, the amount of alcohol in the lungs of a person taking a breathalyzer test is very small. Because this amount varies among individuals, breath tests may overestimate blood alcohol levels. David M. Benjamin, Ph.D., Understanding the Pharmacology of Ethanol.

One rule of thumb regarding blood alcohol concentrations is that one mixed drink will produce a peak blood alcohol level of 0.02 percent in a 150-pound man. The level is lower for wine and beer. If a person is eating while consuming alcohol, the peak blood alcohol concentration would be lower and take longer to reach. The average "burnoff" rate of alcohol is 0.017 percent per hour, leading to the old adage that you can consume about one drink per hour without getting drunk. Charles E. Becker, The Clinical Pharmacology of Alcohol; David M. Benjamin, Ph.D., Understanding the Pharmacology of Ethanol.

Based on the burnoff rate, it is possible to estimate a person's blood alcohol concentration at an earlier time based on a known blood alcohol concentration at a later time. Since the burnoff rate ranges from 0.01 to 0.025 percent per hour, one can generate a range within which a person's true blood alcohol concentration at a certain earlier time would have fallen. Charles E. Becker, The Clinical Pharmacology of Alcohol.

In Commonwealth v. Smith, 35 Mass. App. Ct. 655 (1993), the court discussed the admissibility of expert testimony as to what an individual's blood alcohol level at the time of an incident must have been. This evidence, known as "retrograde extrapolation evidence," is based on the rate at which alcohol is metabolized and the individual's blood alcohol level measured at a specific time following the incident. The court stated that this type of evidence, provided it was admitted via a scientifically acceptable, reliable method, might logically be thought to be of assistance to a jury. Id., see also, Commonwealth v. Cruz, 413 Mass. 686, 698 (1992), and Commonwealth v. Sargent, 24 Mass. App. Ct. 657, 658-659 (1987). The court also noted that a number of other jurisdictions have admitted retrograde extrapolation evidence. Id. (citations omitted).

Statutory blood alcohol concentration levels are not scientific standards. Alcohol affects different people in different ways. Two people may consume the same amount of alcohol in the same amount of time and under the same circumstances, and one may show no outward signs of intoxication whatsoever even with a blood alcohol level above the statutory level, while the other may show signs of intoxication with a blood alcohol level well below the statutory level. Charles E. Becker, The Clinical Pharmacology of Alcohol.

Regardless of the source of a blood alcohol concentration measurement, there will always be some variability in the procedure used. For this reason, two readings are done for breathalyzers and control standards are used. For breathalyzers, one critical control standard is a blank sample that contains no alcohol, and a second is a positive control standard, or calibration test, which is usually at 0.15 percent or 0.20 percent. A breathalyzer test result which has not been "run against a blank" and which did not include a positive control standard is not scientifically valid. In addition, the chemical solutions used in a breathalyzer must be fresh to be accurate. David M. Benjamin, Ph.D., Understanding the Pharmacology of Ethanol.


Alcohol and drug evidence is often something that catches a jury's interest. General admissibility, pharmacology and expert testimony are all matters to consider when assessing the import of such evidence.

The Author

Michael P. Sams is a member in Boston-based Kenney & Sams PC, concentrating in the areas of business litigation, construction law and insurance law. He regularly lectures on litigation practice. Sams chaired Massachusetts Continuing Legal Education's 2005 and 2008 presentations on public construction law reform, served on its deposition workshop faculty from 1999-2005, and chaired MCLE's Taking Depositions with Confidence in 2009.