Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043352 (xerostomia)
 4,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pyridostigmine bromide, a reversible inhibitor of acetylcholinesterase (AChE), is effectively used as a pre-treatment to organophosphate intoxication. Previous studies have shown that an oral dose of 30 mg twice a day produces a sufficient inhibition of the enzyme activity (20-40%) without causing any significant adverse effect. During the Persian Gulf war pyridostigmine was taken for the first time under a chemical warfare threat. We searched for symptoms and complaints that may be related to the medication. Our survey included 213 soldiers who completed a questionnaire regarding possible symptoms and their severity. AChE inhibition level was compared between groups of soldiers with and without complaints. The most frequent symptoms were nonspecific and included dry mouth, general malaise, fatigue and weakness. Typical effects, such as nausea, abdominal pain, frequent urination and rhinorrhea, were infrequent. The severity of the symptoms was generally mild. The symptoms appeared around 1.6 h after taking the medication and recurred after each intake. No correlation was found between levels of cholinesterase and type or severity of complaints. Anxiety, which accompanies wartime, may have contributed to the appearance of significant symptoms. Further investigations concerning the effects of pyridostigmine ingestion under stressful conditions are warranted.
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PMID:Survey of symptoms following intake of pyridostigmine during the Persian Gulf war. 175 41

A 45-year-old-man presented with severe vomiting, constipation, abdominal distention and bilateral ocular abductor palsy. Evaluation revealed diffuse autonomic dysfunction characterized by intestinal pseudo-obstruction, xerophthalmia, xerostomia, postural hypotension, erectile dysfunction and loss of sinus arrhythmia. Paraneoplastic work-up revealed thymoma. Most symptoms resolved after surgical removal of the thymoma. Six weeks later he developed worsening of external ophthalmoparesis with ptosis, responding to acetylcholinesterase inhibitor, confirming myasthenia gravis.
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PMID:Intestinal pseudo-obstruction as initial presentation of thymoma. 1709 Aug 54

Understanding drug pharmacology and mechanism of action can help explain not only therapeutic effects and side effects, but also potential adverse effects when drugs are discontinued. This series of articles will broadly review the potential adverse effects associated with the discontinuation of various psychotropic drugs. This first article focuses on adrenergic, cholinergic, and histamine drugs. After chronic use, abruptly stopping adrenergic receptor drugs can cause rebound anxiety, restlessness, and heart palpitations. Abruptly stopping anticholinergic drugs can lead to an anticholinergic discontinuation syndrome characterized by cholinergic rebound, symptoms of which include nausea, sweating, and urinary urgency. Discontinuation of acetylcholinesterase enzyme inhibitor drugs may be associated with mild anticholinergic-like effects such as dry mouth, constipation, and blurred vision. Abrupt discontinuation of histamine-blocking drugs can be associated with activation, insomnia, and a mild anticholinergic withdrawal syndrome. Tapering, rather than abruptly discontinuing, medication can avoid or minimize medication discontinuation effects.
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PMID:Potential adverse effects of discontinuing psychotropic drugs. Part 1: Adrenergic, cholinergic, and histamine drugs. 2050 69

Muscarinic acetylcholine receptors (mAChRs) have five known subtypes which are widely distributed in both the peripheral and central nervous system for regulation of a variety of cholinergic functions. Atropine is a well known muscarinic subtype non-specific antagonist that competitively inhibits acetylcholine (ACh) at postganglionic muscarinic sites. Atropine is used to treat organophosphate (OP) poisoning and resulting seizures in the warfighter because it competitively inhibits acetylcholine (ACh) at the muscarinic cholinergic receptors. ACh accumulates due to OP inhibition of acetylcholinesterase (AChE), the enzyme that hydrolyzes ACh. However, atropine produces several unwanted side-effects including dilated pupils, blurred vision, light sensitivity, and dry mouth. To overcome these side-effects, our goal was to find an alternative to atropine that emphasizes M1 (seizure prevention) antagonism but has minimum M2 (cardiac) and M3 (e.g., eye) antagonism so that an effective less toxic medical countermeasure may be developed to protect the warfighter against OP and other chemical warfare agents (CWAs). We adopted an in silico pharmacophore modeling strategy to develop features that are characteristics of known M1 subtype-selective compounds and used the model to identify several antagonists by screening an in-house (WRAIR-CIS) compound database. The generated model for the M1 selectivity was found to contain two hydrogen bond acceptors, one aliphatic hydrophobic, and one ring aromatic feature distributed in a 3D space. From an initial identification of about five hundred compounds, 173 compounds were selected through principal component and cluster analyses and in silico ADME/Toxicity evaluations. Next, these selected compounds were evaluated in a subtype-selective in vitro radioligand binding assay. Twenty eight of the compounds showed antimuscarinic activity. Nine compounds showed specificity for M1 receptors and low specificity for M3 receptors. The pK(i) values of the compounds range from 4.5 to 8.5 nM in comparison to a value of 8.7 nM for atropine. 2-(diethylamino)ethyl 2,2-diphenylpropanoate (ZW62841) was found have the best desired selectivity. None of the newly found compounds were previously reported to exhibit antimuscarinic specificity. Both theoretical and experimental results are presented.
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PMID:Discovery of subtype selective muscarinic receptor antagonists as alternatives to atropine using in silico pharmacophore modeling and virtual screening methods. 2352 85

Introduction. Decreased salivary flow and xerostomia are frequent findings in Parkinson's disease (PD), possibly caused by alterations in the parasympathetic tonus. Here we explore salivary acetylcholinesterase (AChE) activity as a potential biomarker in PD. Methods. We measured salivary flow, AChE activity, and total protein concentration in 30 PD patients and 49 healthy controls. We also performed exploratory correlation analyses with disease duration, motor symptom severity, autonomic complaints, and other nonmotor symptoms. Results. PD patients displayed significantly decreased salivary flow rate, significantly increased salivary AChE activity, and total protein concentration. Importantly, the AChE activity/total protein ratio was significantly increased in PD patients, suggesting that increased AChE activity cannot be explained solely by upconcentration of saliva. The Unified PD Rating Scale (UPDRS) score displayed significant correlation with total salivary protein (P = 0.002) and near-significant correlation with salivary flow (P = 0.07). Color vision test scores were also significantly correlated with AChE activity (P = 0.04) and total protein levels (P = 0.002). Conclusion. Salivary AChE activity is increased in PD patients compared to healthy controls. Future studies are needed to elucidate whether this parameter reflects the extent of neuronal damage and parasympathetic denervation in the salivary glands of PD patients.
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PMID:Salivary acetylcholinesterase activity is increased in Parkinson's disease: a potential marker of parasympathetic dysfunction. 2576 37