Hyoscine N-butylbromide inhalation: they know, how about you?

Hayri Ramadan

Department of Emergency Medicine, Ankara Training and Research Hospital, University of Health Sciences, Ankara 06230, Turkey

Dear editor,

Hyoscine N-butylbromide (HNB) is a quaternary ammonium compound with an anticholinergic effect and is commonly used as an antispasmodic drug.[1,2]HNB decreases motility in the gastrointestinal and genitourinary systems by blocking acetylcholine at the parasympathetic nerve endings of smooth muscle and secretory glands.[3]HNB preparations (Buscopan®) have been used in the symptomatic treatment of spasmodic pain of these systems without a prescription in many countries. In this study, we aimed to discuss the effects of HNB inhalation by analyzing two cases who inhaled Buscopan®tablets.

CASE

Two male patients, aged 18 (case 1) and 19 (case 2) years, were brought to the emergency department (ED) by their relatives with symptoms of decreased consciousness for about 30 min. Both patients were agitated and uncooperative on presentation, and had no time or place orientation. They suffered from visual hallucinations and complained of being chased by creatures. The blood pressure (130/75 mmHg [1 mmHg=0.133 kPa] and 120/82 mmHg, respectively), body temperature (36.0 °C and 36.5 °C, respectively) and blood sugar (92 mg/dL and 87 mg/dL, respectively) were normal. The respiratory rate was 25-30 breaths/min, and the oxygen saturation (SpO2) was 98%. The pulse rate was increased (130 beats/min and 127 beats/min, respectively), and electrocardiogram (ECG) showed sinus tachycardia with no ST-T change or arrhythmia. Physical examination revealed normal respiratory and cardiovascular system findings together with mydriatic pupils and weak light reflexes in both cases. Additionally, the sclerae were hyperemic in the second case. On neurological examination, the Glasgow Coma Scale (GCS) was 13, there was no time or place orientation, and the motor findings were normal on all extremities. Deep tendon reflexes and sensory findings could not be checked due to their lack of cooperation. The hemogram, liver and kidney function tests, electrolyte results, and blood gases were within normal limits. The posteroanterior chest X-ray and cranial computed tomography were also normal. The results of the 11-panel drug (amphetamine, methamphetamine, benzodiazepines, acetaminophen, marijuana, phencyclidine, methadone, tricyclic antidepressants, cocaine, barbiturate and opiates) screening test (Drugpro) conducted with urine were negative, and the blood ethanol level was zero.

Intravenous (IV) hydration was started with 0.9% NaCl. A more detailed history was obtained from the relatives of both patients when no reason could be found to explain the existing clinical picture. It was found that the patients had crushed 2 Buscopan®tablets into powder form, wrapped them as cigarettes, and then lighted them and inhaled the smoke for approximately 1 h before the presentation. These findings of the patients were considered to be due to HNB inhalation. The symptoms decreased within 2 h. The hallucinations disappeared after 6 h of follow-up, and the asymptomatic patients were discharged with full recovery.

Both patients were contacted by phone on the second and seventh days and reported no symptoms.

DISCUSSION

HNB is an anticholinergic agent that is effective on muscarinic and nicotinic receptors. The best-known generic name is Buscopan®, and it has been in use in many countries since 1952.[4]The drug has a wide range of clinical indications and is used to decrease abdominal pain, irritable bowel syndrome pain, and renal and biliary colic.[5]Anticholinergic agents cause peripheral and central side effects when taken in high doses.[6]The native form of HNB has attracted attention for its ability to cause central intoxication signs, although it is unable to pass the bloodbrain barrier. Frascht et al[7]performed an experimental study to determine how the central effects of HNB develop by simulating smoking through a mechanism after placing crushed HNB within a cigarette. They found that the burning consisted of two stages. Full burning was performed at 700-900 °C and released carbon monoxide, carbon dioxide, water, and heat. However, it is believed that pyrolysis occurs at a temperature of 100-600 °C, where full burning is not possible and scopolamine is then released. Scopolamine was detected in both the smoke and the ash. In another study, Buscopan®tablets were heated to 160 °C for 9 min, and 47% of HNB was found to be converted to scopolamine.[8]Although not definite, the ability of scopolamine to pass the blood-brain barrier is thought to be related to its lipophilicity. We believe the central effect in our cases developed as a result of the scopolamine that had appeared following pyrolysis.

The number of articles on HNB inhalation in the literature is low.[2,5,7-10]Several cases with severe anticholinergic toxicity as a result of substance use have been reported to the EDs in various states in the USA on similar dates, and the reason was a mixture of a new release of heroin and scopolamine.[9]A questionnaire investigating the effects of HNB was administered to 36 prisoners in another study.[5]These prisoners were found to smoke these cigarettes by crushing an average of 2 tablets of HNB per day. Their symptoms were found to start 15.4 min after smoking, on average, and lasted for 1-3 h. The most commonly reported neurological finding was visual, tactile, and auditory hallucinations. Insomnia, palpitation, flushing, agitation, and concentration disorder were less common findings.

The first death due to HNB in the literature was reported in 2021, again as far as we are aware.[10]An autopsy was performed due to the sudden death of a prisoner. A blood scopolamine level above 1.2 ng/mL was considered toxic/lethal. A high level of scopolamine (1.4 ng/mL) was found in the blood, and the death was attributed to HNB inhalation.[10]

Agitation, palpitation, visual hallucination, and pupil dilation were also present in our cases. The symptoms of the patients started approximately 30 min after inhalation, similar to the literature. Due to our lack of experience in this matter, the patients were monitored in the ED for 6 h and were discharged after recovery. Our patients were only administered 0.9% NaCl IV, as there are only a few cases of intoxication due to HNB inhalation, and no specific treatment is recommended in the literature. The patients did not have any symptoms a week after their discharge from the ED. It was understood in the interviews with the relatives of the patients that the abuse of this drug by inhalation was not at a negligible level and that it is preferred by people with addiction potential, as it is cheap and easy to obtain.

CONCLUSION

It is interesting that people with addiction potential have discovered the pleasurable effects of HNB that doctors do not know. When the literature is reviewed, it can be seen that HNB not only has the potential to be addictive but can also be fatal when taken in high doses. For these reasons, HNB needs to be prescribed with caution, and its sale should be kept under control by health authorities.

Funding:None.

Ethical approval:The informed consent was obtained from the patients for the publication of this case report and any accompanying images.

Conflicts of interest:The author declares that there is no conflict of interest.

Contributors:HR wrote and approved the main body of the report.