Your first patient of the morning is a 19-year-old college student. Her roommate talked her into coming to the emergency department (ED) because the patient is worried that she may have been raped. She remembers being at a fraternity party with some friends the night before. She awoke this morning in an unfamiliar room with her clothing in disarray. While awaiting the arrival of the forensic nurse examiner, the patient’s nurse asks if you need  urine and  blood samples.

Drug-facilitated Sexual Assault

Most sexual assaults, particularly among young women, are committed by an acquaintance or former intimate partner. Many of these assaults are facilitated by “date rape drugs,” which may lower the victim’s inhibitions, render the victim unable to resist, and/or impair memory.

These drugs, of which alcohol is by far the most common, may be either voluntarily consumed by the victim or surreptitiously given to the victim. The prevalence of drug-facilitated sexual assault (DFSA) is difficult to determine, in part because of underreporting. Many date rape drugs are detectable in blood or urine only for a short time; therefore, it is important for emergency physicians to recognize and know how to evaluate patients who have experienced DFSA.¹

Although there is a perception that DFSA is a premeditated crime, it is more often a crime of opportunity. Voluntary consumption of substances, most commonly alcohol and cannabis, most frequently precedes DFSA.² Prescription drugs such as anxiolytics, sleep aids, and muscle relaxers are frequently used. Less often, date rape drugs such as gamma-hydroxybutyrate, Rohypnol, ecstasy, or ketamine are used; these drugs may easily be hidden in alcoholic beverages.

Of note, Rohypnol is not legally available in the United States. Over-the-counter medications including diphenhydramine, and tetrahydrozoline (found in over-the-counter eye drops) have also been implicated in DFSA.

Clinical Presentation and Evaluation

The clinical presentation of patients who have experienced DFSA varies depending upon the drug used and the time between the event and ED presentation. Patients may be uncertain whether they have been sexually assaulted. Common presentations include altered mental status, memory loss, impaired speech or coordination, vomiting, or a state of intoxication that is out of proportion the amount of alcohol consumed. Patients may have sustained injuries for which they have no explanation. Often, patients present because they woke in an unfamiliar place or with disheveled clothing.

As many date rape drugs have short half-lives, rapid collection of blood and urine is key for evidentiary purposes. Some jurisdictions use hair sampling, especially if there is a significant time gap between consumption and collection.³ Protocols for DFSA testing vary among jurisdictions. In some states, blood needs to be collected within 24 hours and urine within 120 hours, although the likelihood of detection decreases with time.