Which of the following medications would the nurse expect the physician to order to reverse a dystonic reaction?
A. prochlorperazine (Compazine)
B. diphenhydramine (Benadryl)
C. haloperidol (Haldol)
D. midazolam (Versed)
Correct Answer: B. diphenhydramine (Benadryl)
Diphenhydramine, 25 to 50 mg I.M. or I.V., would quickly reverse this condition. An acute dystonic reaction is characterized by involuntary contractions of muscles of the extremities, face, neck, abdomen, pelvis, or larynx in either sustained or intermittent patterns that lead to abnormal movements or postures. The symptoms may be reversible or irreversible and can occur after taking any dopamine receptor-blocking agents. Treatment of acute dystonic reaction centers around balancing the disrupted dopaminergic-cholinergic balance in the basal ganglia and discontinuation of the offending agent. The most commonly available drugs in the emergency setting for the treatment of acute dystonic reaction are diphenhydramine and benztropine.
Option A: Prochlorperazine can be used to treat both acute psychotic episodes and chronic mental illnesses. As a first-generation antipsychotic, the drug is better at treating positive symptoms than negative ones, including delusions, hallucinations, agitation, and disorganized speech and behavior.
Option C: Haloperidol is capable of causing dystonia, not reversing it. Due to the blockade of the dopamine pathway in the brain, typical antipsychotic medications such as haloperidol have correlations with extrapyramidal side effects. The extrapyramidal symptoms are muscular weakness or rigidity, a generalized or localized tremor that may be characterized by the akinetic or agitation types of movements, respectively. Haloperidol overdose is also associated with ECG changes known as torsade de pointes, which may cause arrhythmia or cardiac arrest.
Option D: Midazolam would make this client drowsy. Midazolam can be used for anxiolysis and hypnosis during the maintenance phase of general anesthesia and is also superior to thiopental in the maintenance of anesthesia because of the less need for adjunct medications. Midazolam is used as an adjunct medication to regional and local anesthesia for a wide range of diagnostic and therapeutic procedures and has greater patient and physician acceptance.