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Neurological Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
In acute disease, check that the patient's swallowing is safe, and give heparin for prophylaxis of deep-vein thrombosis. Monitor forced vital capacity, and respiratory support may be required. Anticholinesterase drugs may provide immediate relief of symptoms: these prolong the action of acetylcholine by inhibiting the anticholinesterase enzyme. Side effects include bradycardia, increased sweating and salivary secretion, and a depolarizing block (cholinergic crisis) in excessive dosage. Muscarinic side effects can be managed with antagonists such as probantheline. Immunomodulatory treatment with steroids, intravenous immunoglobulin, plasma exchange or azathioprine may be required. Thymectomy is indicated for patients under 40 years whose symptoms are not controlled by anticholinesterase drugs or where CT has suggested the presence of a thymoma.
Targeting the Nervous System
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Anticholinesterase drugs inhibit the active site of acetylcholinesterase reversibly or irreversibly, depending on the interactions with the active site. The two main groups of anticholinesterases include carbamates and organophosphorus compounds. The lead compound for the carbamate inhibiters was sourced from the natural product physostigmine, which was discovered in 1864 as a product from the poisonous calabar bean from West Africa; structure determined in 1925. This compound is still used clinically to treat glaucoma. SAR studies show that the carbamate group is essential to the activity, the benzene ring is important, and the pyrollidine nitrogen is ionised at blood pH; crucial for binding to anionic residues in the active site. The carbamate group is crucial for the inhibitory properties of physostigmine. The mechanism for hydrolysis produces a stable carbonyl intermediate which is the rate-determining step. Molecular structures for some of these compounds are given in Figure 6 of the Supporting Material∗. Due to serious side-effects, its medical uses are limited, so analogues have been made that retain these important features.
Medha Rasayana Plants
Published in Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu, Phytomedicine and Alzheimer’s Disease, 2020
Atanu Bhattacharjee, Biplab Kumar Dey
Swarna Bhasma shows potent antioxidant and free radical scavenging activity. The preparation (25 mg/kg orally for 7 to 10 d) exhibited a nootropic effect in vivo compared with Panax ginseng tea (350 mg/kg orally for 10 d). The preparation showed significant anticholinesterase activity, which may be associated with beneficial effects on cognitive function (Bajaj et al., 1999, 2000).
Chemical composition, enantiomeric analysis and anticholinesterase activity of Lepechinia betonicifolia essential oil from Ecuador
Published in Pharmaceutical Biology, 2022
James Calva, Luis Cartuche, Salomé González, José Vinicio Montesinos, Vladimir Morocho
A few studies about anticholinesterase potential have been reported to date. A recent study from the EO of L. paniculata (Kunth) Epling showed an interesting selective inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes, with IC50 values of 28.2 ± 1.82 and 28.8 ± 1.5 µg/mL, respectively (Panamito et al. 2021). In the present work, we analysed the chemical profiling and the enantiomeric distribution by using gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography coupled to flame ionisation detector (GC-FID), and finally, we assessed the anticholinesterase inhibitory capacity of the EO extracted from the aerial parts of L. betonicifolia. Several species of Lepechinia have been investigated for their biological activities in our research group to validate the ethnomedical uses attributed to this genus and the aim of our study was to preliminarily characterise the potential of this species as a cholinesterase inhibitor. With this basis, we will propose later a complete analysis of the kinetic mechanisms against AChE of the pure major enantiomers found in the EO as well as, the inhibition profile of AChE isolated from brain rats or other related sources to validate the in vitro results.
Role of complement, anti-complement therapeutics, and other targeted immunotherapies in myasthenia gravis
Published in Expert Review of Clinical Immunology, 2022
g MG is a chronic disease requiring not only induction therapy with steroids but also maintenance with steroid-sparing immunosuppressants or immunomodulators. Therapy begins with (a) Anticholinesterases that offer mild symptomatic relief; (b) Corticosteroids that still remain the first-line drug, used by dose escalation from 20 mg daily to even up to 80–100 mg as needed, followed by slow tapering to every other day till reaching the lowest and safest effective dose that controls the disease; (c) Steroid-sparing Immunosuppressants such as Azathioprine, Mycophenolate Mofetil, Cyclosporine, or Tacrolimus, which have variable efficacy but also preference among practitioners, with most preferring mycophenolate 2,000 mg daily or Azathioprine (150 mg daily or 2–3 mg/kg) [1–7]; and (d) Intravenous Immunoglobulin (IVIg) 2 g/kg over 3–4 days or plasmapheresis (every other day, six courses) for patients with significant worsening or MG crises [1–5,7,15–18], choosing the one according to age, cost, availability, comorbidities and venous access [1–5,15–18]. IVIg is being also extensively used as maintenance therapy or as steroid-sparing agent, even though its long-term efficacy remains uncertain and has not been established with controlled studies, as discussed [16]. Subcutaneous Immunoglobulin (sCIg) can be effective in reducing MG disability measures [19], ensuring steady-state serum IgG levels for patients who exhibit wearing-off effect with IVIg or have poor venous access [18].
Organophosphate induced delayed neuropathy after an acute cholinergic crisis in self-poisoning
Published in Clinical Toxicology, 2021
A. K. Pannu, A. Bhalla, R. I. Vishnu, D. P. Dhibar, N. Sharma, R. Vijayvergiya
Patients aged between 13 and 40 years presenting with a history of OP consumption and clinical features of cholinergic toxidrome of typical anticholinesterase poisoning were recruited. The cholinergic crisis comprises muscarinic effects (e.g., bradycardia, increased trachea-bronchial secretions, lacrimation, urination) and nicotinic effects (e.g., muscle weakness, fasciculations) [7–9]. Patients with doubtful history, poisoning with unknown compounds, poisoning with more than one compound, chronic exposure to OP, history of pre-existing medical comorbidities (e.g., neurological disorders, diabetes mellitus, renal failure, hypothyroidism, or chronic alcohol use disorders) were excluded. Because the prevalence of PN increases with age, we also excluded middle and older aged patients [29].