The “Peanut Butter Shot” is a slang term used in emergency medicine and psychiatric care to describe a specific combination of injectable medications given to rapidly sedate a severely agitated or aggressive patient. This cocktail is administered when a patient poses an immediate safety risk to themselves or staff, and verbal de-escalation has failed. The purpose is not to punish but to achieve rapid tranquilization, allowing medical professionals to conduct a necessary physical and psychological assessment.
Why the Slang Term “Peanut Butter Shot” Exists
The nickname originates from the physical characteristics of the medication mixture. When mixed in a single syringe, the combined agents create a notably thick or viscous substance. This high viscosity often gives the solution a cloudy, yellowish, or milky appearance, reminiscent of the texture and color of peanut butter.
The thickness of the liquid requires a larger gauge needle, and the substantial volume of the multi-drug mixture makes the intramuscular (IM) injection quite painful. Since the medication is injected deep into a large muscle, the body absorbs the thick liquid slowly. This slow absorption and large volume can lead to localized pain, stiffness, and a palpable knot at the injection site.
Typical Components of the Combination Injection
The “Peanut Butter Shot” is a chemical combination, sometimes referred to as “B-52,” that traditionally involves three main classes of drugs administered intramuscularly: a first-generation antipsychotic, a benzodiazepine, and a sedating antihistamine.
A typical combination utilizes haloperidol, a potent antipsychotic that blocks dopamine receptors in the brain to reduce psychotic thinking and severe agitation. Because haloperidol alone carries a high risk of causing extrapyramidal symptoms (EPS), it is almost always paired with other agents. Diphenhydramine, a sedating antihistamine, is included primarily to prevent or treat these acute movement side effects, though it also contributes to overall sedation.
The third component is a benzodiazepine, most frequently lorazepam, which acts on GABA receptors to provide an immediate calming and anti-anxiety effect. The combination provides a synergistic effect, achieving rapid sedation more effectively than any single agent alone.
Indications in Emergency and Acute Care
The primary indication for this rapid tranquilization protocol is the acute and severe agitation of a patient in the emergency department or acute psychiatric setting. This aggression is often caused by underlying conditions like acute psychosis, delirium, severe intoxication, or mania. Intervention is required when a patient’s behavior escalates to threatening violence, destroying property, or resisting necessary medical care.
The goal of the injection is to achieve a state of calm, medically referred to as chemical restraint, which is used only as a temporary measure. This allows the medical team to safely perform a comprehensive physical examination, draw necessary lab work, and conduct a mental status assessment. These actions are often impossible to complete while the patient is actively combative.
The rapid onset of action, typically within 15 to 30 minutes, makes this cocktail a fast option for de-escalation in high-risk situations. Administering the shot protects both the patient from accidental self-injury and the staff from physical harm.
The Patient Experience and Modern Protocol Alternatives
From the patient’s perspective, the immediate experience involves the sharp, deep pain of the large-volume injection into the muscle. Within minutes, the combined medications begin to induce deep drowsiness and sedation. A common physical side effect is a sensation of profound muscle heaviness or stiffness, along with dry mouth, due to the anticholinergic properties of the antihistamine component.
While the “Peanut Butter Shot” has been a standard protocol for decades, modern emergency medicine is shifting toward safer and lower-volume alternatives. Current practices prioritize using single-agent therapy or two-drug combinations to minimize the total volume injected and reduce the risk of adverse drug interactions. Newer second-generation antipsychotics, such as intramuscular olanzapine or ziprasidone, are now often favored for their faster action and lower propensity for causing movement disorders like EPS.
The trend is also toward using benzodiazepine monotherapy, such as lorazepam alone, when the cause of agitation is likely anxiety or substance withdrawal. This focus on patient comfort and safety means that the traditional, three-drug “Peanut Butter Shot” is being replaced by more targeted rapid tranquilization protocols.