Hallucinations after Ingesting a High Dose of Benzydamine Hydrochloride

TO THE EDITOR

Benzydamine hydrochloride (BH) is a nonsteroidal anti-inflammatory drug (NSAID) which acts locally.1) There are several different preparations of benzydamine; capsule, mouthwash, dermal cream, preparations are aerosols and vaginal inserts. Side effects include urticaria, erythema, rash, photosensitivity, bronchospasm, and renal function disorders.2) Suggested therapeutic doses are 0.7–1.0 mg/kg per oral.3) Hallucination, agitation, seizures can occur with BH poisoning.4)

Eighteen-year-old male patient who attempted suicide had swallowed 20 pieces of candy containing 50 mg BH. An hour after swallowing the drugs the patient was brought to the emergency room by his family. He said he saw people walking in the emergency room. This was visual hallucination. At physical examination there was no abnormal finding except hallucinations. His previous history was otherwise unremarkable, and he did not report any psychiatric acute or chronic disease. He denied alcohol consumption. Blood pressure 130/80 mmHg, pulse 80 beats/minutes, SpO₂ 96%, body temperature 36.6°C was detected. Electrocardiography was normal sinus rhythm, and there was no pathological findings in routine biochemical tests, blood gases, blood count. Patient was co-sultated with National Poison Information Centre and activated charcoal administration and hospitalization was suggested. Patient was observed at intensive care unit. Then, patients admitted to the intensive care unit of our hospital were monitored. Oral intake was stopped and intravenous hydration started to protect kidney functions. Intravenous pantoprazole was given for possible gastric side effects of benzydamine. Patient’s hallucinations were ongoing 5 hours of hospitalization. He said he saw mices inside the intensive care unit. After 10 hours of hospitalization, hallucinations was totally resolved. Twenty-four hours later the patient received inpatient services. Any toxic effect did not developed so he was observed 3 days and then discharged.

BH abuse for the purpose of suicide is a rare condition. Recreational use of BH, because of its hallucinogen effect, has been reported.2) The mechanism of hallucination development of benzydamine is unknown.

Who abuses BH for recreatinal purposes usually take it with alcohol. It is difficult to distinguish cause of hallucination; benzydamine or alcohol. Also in patients with psychiatric disorders, psychiatric side effects can occur even at normal doses of BH, and overdose can lead to chronic psychosis.5–7) In this case, patients previous history was unremarkable, and he did not reported any psychiatric disorders. He denied alcohol consumption. So we thought that cause of hallucination directly BH.

Benzydamine hydrochloride is a widely used drug. It can cause phsychotic adverse effects at normal dose or overdose. Physicians should be keep in mind the psychiatric side effects of BH.