Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344232 (blurred vision)
 2,072 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The major side effects of racemic oxybutynin (OXY), which is used in the treatment of urinary incontinence are dry mouth (xerostomia) and blurred vision (mydriasis). Highly purified enantiomers of OXY [(R)OXY, (S)OXY] were compared with the racemate both in vitro in functional studies and in vivo in guinea pigs to evaluate their pharmacological action relative to their adverse effects. The affinity of (R)OXY and (S)OXY for different muscarinic receptor subtypes was determined using field stimulated rabbit vas deferens (M1) and guinea pig atria (M2) or bladder (M3) strips. Stereoselective antimuscarinic effects [(R)OXY greater than or equal to (R/S) OXY much greater than (S)OXY] were evident at all three receptor subtypes; the isomeric ratio [(S)OXY/(R)OXY] ranged from 12 to 88. Both (R)OXY and (R/S)OXY were slightly more selective (2-4-fold, P less than .01) for M1 and M3 relative to M2 muscarinic receptors. Stereoselectivity was also evident in vivo for volume-induced urinary bladder contractions as measured by cystometrogram parameters [(S)OXY/(R)OXY approximately 21], mydriasis [(S)OXY/(R)OXY approximately 136] and salivary gland secretory responses [(S)OXY/(R)OXY approximately 30]. The absolute potencies of (R)OXY or (R/S)OXY for mydriasis and salivation were similar to those for inhibition of intravesical bladder pressure. Also, (R)OXY and (R/S)OXY equipotently antagonized cholinergic-mediated CNS effects in mice. Collectively, the data suggest that the activity of (R/S)OXY resides predominantly in the (R)-enantiomer. However, it appears that (R)OXY may offer no significant pharmacological advantage over (R/S)OXY in terms of its principal therapeutic and side effect profile.
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PMID:Enantiomers of oxybutynin: in vitro pharmacological characterization at M1, M2 and M3 muscarinic receptors and in vivo effects on urinary bladder contraction, mydriasis and salivary secretion in guinea pigs. 199 95

Choice of an antidepressant medication is, in part, based on the side effects produced by a drug and the desire to avoid certain reactions in a particular patient. The clinician needs a reliable method of predicting which medications are most likely to produce specific untoward effects. Understanding the synaptic pharmacology of the most commonly used agents could serve as a tool for predicting possible side effects and drug-drug interactions. Antidepressant drugs alter neurotransmitter effects at nerve synapses, probably by blocking norepinephrine and serotonin reuptake, and blockade of neurotransmitter receptor sites - primarily the histamine H1 receptor, the muscarinic receptor, and the alpha-1-adrenoceptor. Possible clinical side effects related to some of these interactions include tachycardia, tremor, and (possibly) male sexual dysfunction (associated with norepinephrine reuptake blockade); sedation (associated with histamine H1 blockade); orthostatic hypotension, dizziness, and reflex tachycardia (associated with alpha-1-adrenoceptor blockade), and blurred vision, dry mouth, and memory dysfunction (associated with muscarinic receptor blockade). Pharmacologic data that demonstrate the potencies and selectivities of the antidepressant drugs for reuptake blockade and receptor site antagonism might allow the clinician to make an informed, rational choice of antidepressant therapy. This paper presents data on drug potencies and selectivities, and attempts to relate these data to anticipated side effects and drug-drug interactions.
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PMID:Pharmacology of antidepressants. 289 25

Tricyclic antidepressants (for example, amitriptyline) and other types of antidepressants (for example, amoxapine and maprotiline) are competitive antagonists of muscarinic acetylcholine receptors, the predominant class of acetylcholine receptors in the brain. Some evidence suggests that this muscarinic receptor blockade in brain alleviates depression. However, all tricyclic antidepressants appear to be equally effective in treating depression despite having differences in their antimuscarinic potencies while having similar ranges of therapeutic blood levels. It is more likely that the antimuscarinic potency of antidepressants is related mainly to the frequency with which they cause such symptoms as blurred vision, dry mouth, and urinary retention. Information on the antimuscarinic potency and other receptor-blocking potencies of antidepressant agents can be helpful in minimizing or avoiding certain side effects when these drugs are given to patients.
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PMID:Antimuscarinic and other receptor-blocking properties of antidepressants. 613 Jan 92

A wealth of clinical evidence supports the view that muscarinic receptor antagonists are effective in the treatment of overactive bladder. However, treatment-limiting adverse effects such as dry mouth, constipation, and blurred vision have restricted the usefulness of previously available agents, such as oxybutynin. A real need therefore existed for effective and well-tolerated agents for the long-term management of the troublesome symptoms of overactive bladder. This review outlines the various approaches that have been used in attempts to overcome the tolerability problems of oxybutynin. It also describes how advances in our understanding of muscarinic receptors and bladder function has led to the potential development of either tissue- or subtype-selective antimuscarinic agents with improved tolerability. Drugs that have been developed in this way include tolterodine and darifenacin, each of which shows some bladder selectivity in animal models. Unlike darifenacin, however, the bladder selectivity of tolterodine has been confirmed by numerous clinical studies. Tolterodine's improved tolerability compared with oxybutynin, along with its equivalent therapeutic efficacy at recommended dosages, permits patients to experience the beneficial effects of long-term treatment. Tolterodine therefore represents a real alternative for the long-term management of overactive bladder. The results of ongoing clinical studies with darifenacin are awaited before it can be concluded that selective antagonism of M(3) receptors leads to improved tolerability over existing agents in the treatment of overactive bladder. Similarly, the potential improvements in tolerability associated with different dosage formulations of oxybutynin, and the clinical utility of S-oxybutynin, are yet to be conclusively demonstrated.
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PMID:Muscarinic receptor antagonists in the treatment of overactive bladder. 1076 51

Overactive bladder syndrome (OAB) is a symptomatic diagnosis based on the presence of urgency, with or without urge incontinence, and usually accompanied by frequency and nocturia, in the absence of obvious pathologic or metabolic disease. Initial management of OAB requires an integrated approach using behavioral and pharmacologic methods. Patients should be educated about the functioning of the lower urinary tract system, fluid and dietary management, timed or prophylactic voiding and bladder training regimens, the keeping of micturition charts or bladder diaries, and pelvic floor exercises. Although the effectiveness of muscarinic receptor antagonists for the treatment of OAB has been shown, adverse effects, such as dry mouth, constipation, and blurred vision have somewhat limited their usefulness. Newer agents that are more bladder selective have been and continue to be developed. The concept of clinical effectiveness-a combination of efficacy, tolerability, and compliance-can be used to evaluate not only how well a drug works, but also the side-effect profile and bothersomeness and how likely patients are to continue treatment. Patients who do not respond to antimuscarinic treatment of OAB may do so because of a variety of nonpharmacologic and pharmacologic reasons. Most cases of OAB are not cured, but rather the symptoms are reduced, with an associated improvement in the patients' quality of life. Patients who have failed behavioral and pharmacologic intervention may respond to neuromodulation and augmentation cystoplasty. Future approaches may include (1) other types of systemic pharmacologic therapy; (2) intravesical administration of drugs, including blockers of afferent input; (3) intradetrusor injection of botulinum toxin; (4) the use of tissue engineering to simplify augmentation cystoplasty; (5) genetic interventions to reverse neuroplasticity changes; and (6) combinations of these approaches.
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PMID:Diagnosis and treatment of the overactive bladder. 1466 3

The pharmacokinetic profile of solifenacin succinate (YM905; Vesicare), a new once-daily bladder-selective muscarinic receptor antagonist, was examined in 2 controlled trials of healthy young men. A single-dose study evaluated 5-, 10-, 20-, 40-, 60-, 80-, and 100-mg doses. A multidose study evaluated 5-, 10-, 20-, and 30-mg doses. In the single-dose study, mean time to maximal concentration and elimination half-life ranged from 3.3 to 4.8 and from 40.2 to 57.6 hours, respectively; in the multidose study, the corresponding ranges were 2.9 to 5.8 and 45.0 to 64.8. Plasma concentration and area under the curve increased linearly with single doses in both trials. At steady state, a less regular increase was seen, with higher values in the 20-mg group than in the 30-mg group. All doses in the single-dose study were well tolerated. At steady state, only the 30-mg dose was not well tolerated. The most commonly reported adverse events were dry mouth, blurred vision, and headache. Solifenacin 5 and 10 mg, either as single doses or at steady state, had minimal effect on salivary flow, visual nearpoint, and the incidence of adverse events. Solifenacin was well tolerated up to single doses of 100 mg and after multiple doses of 20 mg. Its pharmacokinetic profile makes it suitable for qd administration.
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PMID:Pharmacokinetics and safety of solifenacin succinate in healthy young men. 1531 30

The primary pharmacological therapy for overactive bladder syndrome is muscarinic receptor antagonists. Muscarinic receptor blockade is effective in decreasing the symptoms of urinary urgency and urgency incontinence, but can be associated with troublesome complications, such as dry mouth, blurred vision, constipation and CNS side effects. Trospium chloride, an antimuscarinic medication, has been available in Europe for > 20 years and has recently been approved by the FDA for the treatment of overactive bladder. Trospium chloride is a quaternary amine that is minimally metabolised, not highly protein bound and, importantly, has not been demonstrated to cross the unaltered blood-brain barrier in healthy volunteers. Some characteristics of this unique antimuscarinic agent and the European experience with trospium chloride are reviewed in this article.
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PMID:Trospium chloride: the European experience. 1680 22

Overactive bladder (OAB) is a syndrome characterized by urinary urgency, with or without urgency urinary incontinence, usually with frequency and nocturia. OAB symptoms are often associated with detrusor overactivity (DO). Like OAB symptoms, the prevalence of DO increases with age and can have a neurogenic and/or myogenic aetiology. Bladder outlet obstruction can be a contributing factor in DO, possibly through cholinergic denervation of the detrusor and supersensitivity of muscarinic receptors to acetylcholine, although the prevalence of OAB is similar in men and women across age groups. Acetylcholine is the primary contractile neurotransmitter in the human detrusor, and antimuscarinics exert their effects on OAB/DO by inhibiting the binding of acetylcholine at muscarinic receptors M(2) and M(3) on detrusor smooth muscle cells and other structures within the bladder wall. Worldwide, there are six antimuscarinic drugs currently marketed for the treatment of OAB: oxybutynin, tolterodine, propiverine, trospium, darifenacin, and solifenacin. Each has demonstrated efficacy for the treatment of OAB symptoms, but their pharmacokinetic and adverse event profiles differ somewhat due to structural differences (tertiary vs quaternary amines), muscarinic receptor subtype selectivities, and organ selectivities. Antimuscarinics are generally well tolerated, even in special populations (e.g. men with bladder outlet obstruction, elderly patients, children). The most frequently reported adverse events in clinical studies of antimuscarinics are dry mouth, constipation, headache, and blurred vision; few patients withdraw from clinical trials because of adverse events. Development of an antimuscarinic with functional selectivity for the bladder would reduce the occurrence of antimuscarinic adverse events. The therapeutic potential of several other agents, such as alpha(3)-adrenoceptor agonists, purinergic receptor antagonists, phosphodiesterase inhibitors, neurokinin-1 receptor antagonists, opioids, and Rho-kinase inhibitors, is also under investigation for the treatment of OAB.
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PMID:Muscarinic receptor antagonists for overactive bladder. 1792 84

Antimuscarinic medications are used to treat nonneurogenic overactive bladder refractory to nonpharmacologic therapy. Side effects such as dry mouth, constipation, blurred vision, dizziness, and impaired cognition limit the tolerability of therapy and are largely responsible for high discontinuation rates. Oxybutynin is a potent muscarinic receptor antagonist whose primary metabolite after first-pass hepatic metabolism is considered largely responsible for its associated anticholinergic side effects. Transdermal administration of medications bypasses hepatic processing. Specifically with oxybutynin, whose low molecular weight permits transdermal administration, bioavailability of the parent drug with oral administration is less than 10%, whereas with transdermal delivery is a minimum of 80%. The result has been an improved side effect profile in multiple clinical trials with maintained efficacy relative to placebo; however, the drug may still be discontinued by patients due to anticholinergic side effects and application site reactions. Transdermal oxybutynin is available as a patch that is changed every 3-4 days, a gel available in individual sachets, or via a metered-dose pump that is applied daily. The transdermal patch was briefly available as an over-the-counter medication for adult women, although at this time all transdermal formulations are available by prescription only.
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PMID:An update on the use of transdermal oxybutynin in the management of overactive bladder disorder. 2703 21

Antimuscarinic agents are now widely used as the pharmacological therapy for overactive bladder (OAB) because neuronal (parasympathetic nerve) and non-neuronal acetylcholine play a significant role for the bladder function. In this review, we will highlight basic and clinical aspects of eight antimuscarinic agents (oxybutynin, propiverine, tolterodine, solifenacin, darifenacin, trospium, imidafenacin, and fesoterodine) clinically used to treat urinary dysfunction in patients with OAB. The basic pharmacological characteristics of these eight antimuscarinic agents include muscarinic receptor subtype selectivity, functional bladder selectivity, and muscarinic receptor binding in the bladder and other tissues. The measurement of drug-receptor binding after oral administration of these agents allows for clearer understanding of bladder selectivity by the integration of pharmacodynamics and pharmacokinetics under in vivo conditions. Their central nervous system (CNS) penetration potentials are also discussed in terms of the feasibility of impairments in memory and cognitive function in elderly patients with OAB. The clinical aspects of efficacy focus on improvements in the daytime urinary frequency, nocturia, bladder capacity, the frequency of urgency, severity of urgency, number of incontinence episodes, OAB symptom score, and quality of life (QOL) score by antimuscarinic agents in patients with OAB. The safety of and adverse events caused by treatments with antimuscarinic agents such as dry mouth, constipation, blurred vision, erythema, fatigue, increased sweating, urinary retention, and CNS adverse events are discussed. A dose-dependent relationship was observed with adverse events, because the risk ratio generally increased with elevations in the drug dose of antimuscarinic agents. Side effect profiles may be additive to or contraindicated by other medications.
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PMID:Basic and clinical aspects of antimuscarinic agents used to treat overactive bladder. 2970 23


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