A nurse in a substance abuse clinic is assessing a client who was recently prescribed disulfiram. The patient suddenly stopped taking this medication and is now complaining of severe nausea and vomiting. What should the nurse suspect is likely the cause of the client's distress?

A. Disulfiram itself does not usually cause nausea and vomiting unless combined with alcohol. B. Disulfiram is used as aversion therapy for alcohol dependence. If the client consumes alcohol while on disulfiram, it produces an acetaldehyde reaction causing severe nausea, vomiting, flushing, hypotension, and palpitations. C. Overdose may cause neurologic or cardiac issues, but the hallmark reaction is linked to alcohol consumption. D. Allergic reactions would typically involve rash, swelling, or respiratory distress, not severe nausea and vomiting alone.