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Concept: Muscarinic antagonist


Abstract “Death rattle” is a term used to describe the noisy sound produced by dying patients caused by the oscillatory movements of secretions in the upper airways. Antimuscarinic drugs, including atropine, scopolamine (hyoscine hydrobromide), hyoscine butylbromide, and glycopyrronium, have been used to diminish the noisy sound by reducing airway secretions. We report on the effectiveness of sublingual atropine eyedrops in alleviating death rattle in a terminal cancer patient. We present a 58-year-old man with pancreatic cancer who was admitted to our hospital because of severe dyspnea, cough, and death rattle with excessive bronchial secretion as a result of multiple lung metastases. We administered 1% atropine eyedrops sublingually to obviate the need for subcutaneous infusions and to prevent somnolence. On the basis of our experience, we conclude that atropine eyedrops, administered sublingually for distressing upper respiratory secretions, may be an effective alternative to the injection of antimuscarinic drugs, or as an option when other antimuscarinic formulations are not available.

Concepts: Cancer, Death, Muscarinic antagonists, Respiratory system, Anticholinergic, Hyoscyamine, Scopolamine, Muscarinic antagonist


Cyperus species are famous for their traditional uses and very commonly used for their anti-spasmodic and anti-diarrheal activities. Cyperus niveus Retz. is used in local traditional system of medicine in Pakistan to treat various gastrointestinal ailments.

Concepts: Folklore, Muscarinic antagonist, Cyperus, Antispasmodic


Scopolamine is a potent anticholinergic compound used commonly for the prevention of postoperative nausea and vomiting. Scopolamine can cause atypical anticholinergic syndromes due to its prominent central antimuscarinic effects.

Concepts: Vomiting, Anticholinergic, Nausea, Metoclopramide, Postoperative nausea and vomiting, Scopolamine, Muscarinic antagonist, Soulfly


We report the case of a 60-year-old woman with metastatic breast cancer whose intractable nausea and vomiting were effectively managed with a hyoscine hydrobromide (scopolamine) patch. Contrast swallow revealed oesophageal spasm to be the underlying cause. Symptom relief may be attributed to the antimuscarinic properties of the patch, allowing lower oesophageal sphincter relaxation. Following patch use she was able to enjoy small meals and fluids without symptoms. This is the first time this mechanism of action of scopolamine for alleviating nausea and vomiting has been described in the literature.

Concepts: Cancer, Breast cancer, Transdermal patch, Chemotherapy, Symptoms, Motion sickness, Scopolamine, Muscarinic antagonist


Traditionally, the non-selective muscarinic antagonist scopolamine has been used to induce episodic memory impairments as found in Alzheimer’s disease (AD). However, it also impairs attention and induces drowsiness. Muscarinic antagonists more selective for the M1 receptor might, therefore, be preferred.

Concepts: Alzheimer's disease, Memory, Receptor antagonist, Muscarinic acetylcholine receptor, Amnesia, Semantic memory, Scopolamine, Muscarinic antagonist


Grid cells of the medial entorhinal cortex exhibit a periodic and stable pattern of spatial tuning that may reflect the output of a path integration system. This grid pattern has been hypothesized to serve as a spatial coordinate system for navigation and memory function. The mechanisms underlying the generation of this characteristic tuning pattern remain poorly understood. Systemic administration of the muscarinic antagonist scopolamine flattens the typically positive correlation between running speed and entorhinal theta frequency in rats. The loss of this neural correlate of velocity, an important signal for the calculation of path integration, raises the question of what influence scopolamine has on the grid cell tuning as a read out of the path integration system. To test this, the spatial tuning properties of grid cells were compared before and after systemic administration of scopolamine as rats completed laps on a circle track for food rewards. The results show that the spatial tuning of the grid cells was reduced following scopolamine administration. The tuning of head direction cells, in contrast, was not reduced by scopolamine. This is the first report to demonstrate a link between cholinergic function and grid cell tuning. This work suggests that the loss of tuning in the grid cell network may underlie the navigational disorientation observed in Alzheimer’s patients and elderly individuals with reduced cholinergic tone. © 2014 Wiley Periodicals, Inc.

Concepts: Mathematics, Receptor, Correlation and dependence, Neurotransmitter, Muscarinic acetylcholine receptor, The Grid, Muscarinic antagonist