Anticholinergic Toxidrome as a Possible Explanation for Methylene Blue Toxicity

BACKGROUND Methylene blue has multiple uses in medicine. It is generally used to treat refractory vasoplegia and methemoglobin toxicity, and can be used as a dye to localize the parathyroid glands intra-operatively. In refractory vasoplegia, methylene blue inhibits endothelial nitric oxide and guanylate cyclase, causing vasoconstriction and potentially stabilizing blood pressure. Multiple complications have been associated with the use of methylene blue. These are related to either the sole effect of methylene blue or the combined effect of methylene blue and certain antidepressants, such as selective serotonin reuptake inhibitors (SSRIs). To the best of our knowledge, in the setting of post-cardiac surgery vasoplegia, there have been no reports of the neurological toxicity of methylene blue in the absence of SSRI use. In this case report, we describe the anticholinergic manifestations associated with the use of methylene blue in post-cardiac surgery vasoplegia. CASE REPORT A male patient in his mid-sixties with severe mitral regurgitation underwent elective mitral valve replacement. Postoperatively, he was hypotensive and required a high dose of vasopressors. Methylene blue was administered to treat refractory vasoplegia. The patient became anuric and febrile, with bilateral mydriasis. Internal cooling and continuous renal replacement therapy were initiated, and symptoms rapidly resolved. The patient was discharged after prolonged hospitalization with a permanent catheter for hemodialysis. CONCLUSIONS Anticholinergic toxidrome may explain the neurological adverse effects associated with high doses of methylene blue. Physicians should be cautious when using methylene blue in combination with other anticholinergic drugs and in conditions of renal failure. The development of methylene blue toxicity warrants the urgent discontinuation of the agent and early drug elimination.

[Deliberate intoxication with Datura Stramonium, a rare cause of confusion]

Many drugs can be responsible for this syndrome. Although it remains rare, poisoning by Datura Stramonium should be considered in the event of anticholinergic syndrome in the elderly, particularly in the event of anticholinergic manifestations.

EEG changes as an indication of central nervous system involvement following cyclopentolate 1% eye drops; a randomized placebo-controlled pilot study in a pediatric population

To compare EEG-patterns after instillation of cyclopentolate versus placebo eye drops. Prospective, randomized, placebo-controlled, and observational pilot study is presented. Ophthalmology outpatient clinic Dutch metropolitan hospital. Healthy 6- to 15-year-old volunteers with normal or low BMI requiring a cycloplegic refraction/retinoscopy. Randomized; 1 visit 2 drops cyclopentolate-1% and 1 visit 2 drops placebo (saline-0.9%). Single-blind: conducting researcher. Double blind: subjects, parents, clinical-neurophysiology staff, neurologist, and statistician. A 10-min baseline EEG-recording, drop-application, and follow-up to at least 45 min. Primary outcome: Detection of CNS changes, i.e. EEG-pattern changes, following two drops of cyclopentolate-1%. Secondary outcome: Determination of the extent of these pattern changes. Thirty-six cyclopentolate-1% saline-0.9% EEG registrations were made in 33 subjects;  18 males and 15 females. Three subjects were tested twice (interval 7 months). Nine out of fourteen (64%) of the 11- to 15-year-old children reported impaired memory, attention, alertness, as well as mind wandering following cyclopentolate. Drowsiness and sleep were seen in EEG-recordings of 11 subjects (33%) following cyclopentolate. We observed no drowsiness nor sleep during placebo recordings. The mean time to drowsiness was 23 min. Nine subjects arrived in stage-3 sleep but none arrived in REM-sleep. In subjects without sleep (N=24), significant changes compared to placebo-EEG were present for many leads and parameters. The main findings during awake eye-open recording were as follows: 1) a significant increase of temporal Beta-1,2 and 3-power, and 2) a significant decrease in: a) the parietal and occipital Alpha-2-power, b) the frontal Delta-1-power, c) the frontal total power, and d) the occipital and parietal activation synchrony index. The former finding reflects cyclopentolate uptake in the CNS, and the latter findings provide evidence for CNS suppression. Cyclopentolate-1% eye drops can affect the CNS and may cause altered consciousness, drowsiness, and sleep with concomitant EEG results in both young children and children in puberty. There is evidence that cyclopentolate has the potency to act as a short acting CNS depressant. Nevertheless, however, cyclopentolate-1% can safely be used in children and young adolescents.

Central anticholinergic syndrome secondary to atropine eye drops: A case study

Atropine eye drops are frequently used in the treatment of keratitis and during ophthalmic surgery. We described a rare complication of central anticholinergic syndrome secondary to atropine eye drops.

Acute Bilateral Fixed Mydriasis Caused by Lupini Bean Intoxication

Lupini beans are legume seeds of the genus Lupinus, consumed in many parts of the world. The main species are Lupinus mutabilis, Lupius angustifolius, and Lupinus albus. The latter is commonly eaten as a snack in Mediterranean countries. The beans are very rich in alkaloids, which give them a bitter taste. One of these alkaloids was shown to cause anticholinergic effects. Lupini beans, if improperly prepared, can cause toxicity manifesting as an anticholinergic syndrome. We present the case of a 50-y-old woman who presented with bilateral mydriasis, mouth dryness, and anxiety. We confirmed that the patient consumed partially debittered lupini beans a few hours before presentation. The rest of her physical and ophthalmic examination results were within normal limits. Her symptoms resolved without therapy within 12 h from presentation and were attributed to ingestion of incorrectly prepared lupine seeds.

Anticholinergic syndrome after atropine overdose in a supposedly homeopathic solution: a case report

BACKGROUND

A 53-year-old male with no pre-existing conditions and no permanent medication presented to our emergency department with an anticholinergic syndrome including confusion, anxiety, ataxia and dysarthria after ingestion of a homeopathic solution containing Atropa belladonna extract supposedly in a D4 dilution.

METHODS

Atropine sulphate was quantitatively analysed in serum and the homeopathic preparation via liquid chromatography/mass spectrometry.

RESULTS

Analysis revealed concentrations of approximately 3 mg/mL atropine sulphate in the homeopathic solution and a serum level of 5.7 ng/mL (±1.4) in the patient's blood proving a 600-fold overdose of atropine due to a production error of the homeopathic dilution. The patient was observed and recovered without further intervention.

CONCLUSION

Rare but possibly dangerous manufacturing errors should be considered when faced with symptoms occurring after ingestion of homeopathic or holistic remedies.

Anticholinergic toxicity in a one-year-old male following ingestion of Lupinus mutabilis seeds: case report

CONTEXT

The seeds from Lupinus mutabilis Sweet, also called "chocho", are an important part of the diet in several countries in South America. Prior to consumption, processing is required to remove toxic alkaloids. These alkaloids are known to have pharmacological properties as antiarrhythmics, antimuscarinics and hypoglycemics.

CASE REPORT

We report a case in which a one-year-old male initially presented with altered mental status and respiratory distress and subsequently developed symptoms of anticholinergic toxicity, after ingesting a large amount of chocho seeds.

CONCLUSION

In spite of going through a difficult clinical condition, the subject evolved favorably through receiving supportive treatment. The seeds from Lupinus mutabilis provide nutritional benefits when consumed, but people need to know their risks when these seeds are consumed without proper preparation.

Acute poisoning due to ingestion of Datura stramonium - a case report

Datura stramonium (DS) is a widespread annual plant, containing atropine, hyoscyamine, and scopolamine, which can produce poisoning with a severe anticholinergic syndrome. Teenagers ingest the roots, seeds or the entire plant to obtain its hallucinogenic and euphoric effects. We presented the case of a 22 year old male who was admitted to the Emergency Room in a coma after consuming Datura stramonium, 2 hours earlier. The patient presented with fever, tachycardia with right bundle branch block, and urinary retention. Rapid sequence induction and intubation was performed immediately, with sedation and assisted-control mechanical ventilation, after being transferred to the Intensive Care Unit. The patient received activated charcoal, in repeated doses, external and internal cooling was applied, and an infusion of neostigmine was started. The biological assessment revealed rhabdomyolysis and prevention of renal failure was initiated. After a proper neurological evaluation, 36 hours after using Datura stramonium, the patient was extubated and transferred to the Psychiatric ward for further assessment and care.

Transient symptomatic worsening by atropine in opsoclonus-myoclonus syndrome

Opsoclonus-myoclonus syndrome (OMS) is characterized by abnormal eye and systemic involuntary movements, as well as cerebellar ataxia. Some sedatives and anesthetics worsen movements associated with OMS, while there is no known report of a negative effect of atropine. We report on sedation in two patients with OMS. Involuntary movements were transiently worsened after using atropine with midazolam or thiamylal in both, but were not seen when atropine was not used. We speculated that atropine has the potential to exacerbate involuntary movements in OMS due to vulnerability to this agent via unknown mechanisms.

Anticholinergic syndrome following an unintentional overdose of scopolamine

Scopolamine hydrobromide (hyoscine) is an antimuscarinic drug which is primarily used in the prophylaxis and treatment of motion sickness and as a premedication to dry bronchial and salivary secretions. In acute overdosage, the main clinical problem is central nervous system (CNS) depression. In Australia, tablets containing scopolamine hydrobromide 0.3 mg are available over the counter in packs of ten. The recommended dose for adults is one to two tablets as a single dose, repeated four to six hours later, if required. The maximum dose stated on the pack is four tablets over a 24-hour period with a caution regarding drowsiness and blurred vision. We describe a patient who presented with symptoms of anticholinergic syndrome secondary to an unintentional overdose of scopolamine. Whilst at work, the patient noticed that he had forgotten his prescribed medication, domperidone, at home; a friend gave him some travel sickness medication which contained scopolamine for relief of nausea. On a previous occasion, he had experienced a similar, less severe reaction with another anticholinergic agent, loperamide. This report highlights the need to consider nonprescription products, ie, over the counter medications, herbal/nutritional supplements as causes of anticholinergic syndrome when a patient presents with symptoms suggestive of this diagnosis.