Repeated delirium from homatropine eye-drops. A case report

Delirium and Its Pharmacological Causes in Older People, Part 1

Delirium is a syndrome that can arise from many causes or underlying conditions, and though it has been reported in younger patients, it is more prevalent in older people, though it can occur in other age groups as well. Identifying delirium is challenging in older people because of the coexistence of underlying dementia or depression, which may further complicate the presentation. Drug-induced delirium is one of the major causes of delirium, and evaluation of this potential cause or contribution is an important component of the evaluation process, since it can lead to poor patient outcomes. This article will review the epidemiology, pathophysiology, evaluation, diagnostic process, and causes of delirium in older people, with a focus on the pharmacological causes.

A CAR RNA FISH assay to study functional and spatial heterogeneity of chimeric antigen receptor T cells in tissue

Chimeric antigen receptor (CAR) T cells are engineered cells used in cancer therapy and are studied to treat infectious diseases. Trafficking and persistence of CAR T cells is an important requirement for efficacy to target cancer. Here, we describe a CAR RNA FISH histo-cytometry platform combined with a random reaction seed image analysis algorithm to quantitate spatial distribution and in vivo functional activity of a CAR T cell population at a single cell resolution for preclinical models. In situ, CAR T cell exhibited a heterogenous effector gene expression and this was related to the distance from tumor cells, allowing a quantitative assessment of the potential in vivo effectiveness. The platform offers the potential to study immune functions of genetically engineered cells in situ with their target cells in tissues with high statistical power and thus, can serve as an important tool for preclinical assessment of CAR T cell effectiveness.

DARK Classics in Chemical Neuroscience: Atropine, Scopolamine, and Other Anticholinergic Deliriant Hallucinogens

Anticholinergic drugs based on tropane alkaloids, including atropine, scopolamine, and hyoscyamine, have been used for various medicinal and toxic purposes for millennia. These drugs are competitive antagonists of acetylcholine muscarinic (M-) receptors that potently modulate the central nervous system (CNS). Currently used clinically to treat vomiting, nausea, and bradycardia, as well as alongside other anesthetics to avoid vagal inhibition, these drugs also evoke potent psychotropic effects, including characteristic delirium-like states with hallucinations, altered mood, and cognitive deficits. Given the growing clinical importance of anti-M deliriant hallucinogens, here we discuss their use and abuse, clinical importance, and the growing value in preclinical (experimental) animal models relevant to modeling CNS functions and dysfunctions.

Systemic adverse effects of topical ophthalmic agents. Implications for older patients

Topical ophthalmic medications are widely prescribed by growing numbers of eye-care professionals. Increasingly, these agents are being prescribed by optometrists and ophthalmic-trained nurses in addition to ophthalmologists and general practitioners. As the number and variety of topical agents on the market rises, and as the number of clinicians involved in prescribing those agents increases; the risk of systemic adverse effects will also increase. Thus, professionals involved in the care of these patients must be aware of the risks associated with these drugs in order to minimise the likelihood of complications. Moreover, inadequate training may result in the clinician failing to associate a topical medication with a systemic condition, allowing an adverse effect to pass unrecognised. It is therefore in the interest of the ophthalmic and pharmaceutical communities to improve awareness of the potential dangers intrinsic in the use of topical eye medications. It is the elderly population who are at greatest risk of experiencing systemic adverse effects of topical agents. Chronic ophthalmic diseases, and hence long term ophthalmic drop treatments, are more prevalent among older people. Such individuals are also likely to have other medical conditions (e.g. cardiac, respiratory or neurological disease) that may be induced or exacerbated by topical ophthalmic agents. Moreover, polypharmacy is common in elderly people, and this is associated with an increased risk of drug interactions.

Systemic toxicity from ocular homatropine

Toxidromes are well known to emergency physicians. An unclear or incomplete history and subtle findings on physical examination make the diagnosis of poisonings challenging. This article reports a patient who had an acute onset of visual hallucinations, pressured speech, and mania. Although she denied taking any medications, she was ultimately diagnosed as having anticholinergic toxicity. On further questioning of family members, it was discovered that she was being treated for anterior uveitis with 5% homatropine. This case illustrates the potential role of ocular medications in systemic toxicity. Patients often do not consider eyedrops to be medications, and their use may be overlooked in the medical history. It also is important to educate patients and medical staff in methods to minimize systemic toxicity when using ocular medication.

Eye drops--the hidden poison

Eye drops are very commonly prescribed but their potential for systemic absorption and serious toxicity may be forgotten. This paper examines patterns of prescription of eye drops in Scotland by general practitioners. A review of the serious systemic features and toxicity, and their management, of commonly used eye drops is undertaken. Practical recommendations for the monitoring of such effects in clinical practice are made.