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)

Scopolamine is the most effective single drug for the prophylaxis and treatment of motion sickness. However, oral or injected scopolamine displays a comparatively short duration of action (5-6 hours), and leads to deleterious side effects on autonomic and central nervous system cholinergic functions. The transdermal scopolamine system was designed to reduce these problems, but while it does deliver scopolamine over a prolonged time period (72 h), deleterious side effects are also produced. Transdermal scopolamine provides significant motion sickness protection, similar in extent to that provided by oral scopolamine or dimenhydrinate. Its autonomic nervous system effects comprise reduced salivation, bradycardia, and blurred vision due to reduced visual accommodation. The visual problems increase following repeated patch applications, with hypermetropic ("long sighted") individuals particularly at risk. Central nervous system effects comprise reduced memory for new information, impaired attention, and lowered feelings of alertness. Variation in response to transdermal scopolamine has also been reported, both between individuals, and between different patch applications on the same individual.
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PMID:Transdermal scopolamine: a review of its effects upon motion sickness, psychological performance, and physiological functioning. 264 72

Scopolamine and placebo transdermal patches were applied on alternating days to 12 normal volunteer subjects. Psychological performance tasks, physiological assessments, a subjective feeling state questionnaire, and a sleep questionnaire were completed each day. Transdermal scopolamine produced significant decrements in memory task performance, daytime feelings of alertness, ease of waking, and alertness following waking, while resting heart rates were lowered. Significant drug x patch number interaction effects were present with memory for new information, letter cancellation omission errors, rapid visual information processing reaction time, and self-rated ease of getting to sleep, but there was no consistent pattern to the changes following successive patches. Visual problems (blurred vision, longer visual near point) increased following successive scopolamine patches, but the changes in task performance were not related to these visual changes.
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PMID:Transdermal scopolamine: effects of single and repeated patches upon psychological task performance. 362 92

Hyoscine (scopolamine) is a competitive inhibitor of the muscarinic receptors of acetylcholine and it has been shown to be one of the most effective agents for preventing motion sickness. However, a relatively high incidence of side effects and a short duration of action has restricted the usefulness of this agent when administered orally or parenterally, and to counter this a novel transdermal preparation of hyoscine has been developed. Pharmacokinetic studies indicate that this new method for administering hyoscine controls the absorption process and the rate of drug entry into the systemic circulation over an extended period (72 hours), providing a means of delivery which is similar to a slow intravenous infusion. However, recent evidence suggests that the response to transdermal hyoscine treatment is variable and this may reflect pharmacokinetic differences between individuals. Controlled therapeutic trials have indicated that a single transdermal hyoscine patch is significantly superior to placebo and oral meclozine (meclizine) in preventing motion sickness. Trials comparing transdermal hyoscine with oral dimenhydrinate have failed to establish any significant differences in efficacy between the 2 drugs in small numbers of subjects, although there was always a more favourable trend towards the transdermal system. In patients with acute vertigo, transdermal hyoscine and oral meclozine were equally efficacious and both were significantly better than placebo in reducing the number of attacks of vertigo. Although transdermal hyoscine has been associated with a lower incidence of side effects than orally or parenterally administered hyoscine hydrobromide, adverse systemic effects have still been frequently reported. Most commonly cited have been dry mouth, drowsiness and impairment of ocular accommodation, including blurred vision and mydriasis (some ocular effects reported may be due to finger-to-eye contamination). Adverse central nervous system (CNS) effects, difficulty in urinating, rashes and erythema have been reported only occasionally. Thus, preliminary evidence suggests transdermal hyoscine may offer an effective and conveniently administered alternative for the prevention of motion-induced nausea and vomiting in certain situations. However, the duration of its clinical effectiveness, and its relative efficacy and tolerability compared with other agents needs to be confirmed in a few additional well-designed studies.
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PMID:Transdermal hyoscine (Scopolamine). A preliminary review of its pharmacodynamic properties and therapeutic efficacy. 388 52

Three placebo-controlled double-blind studies in healthy volunteers were performed to reveal the psychophysiological effects of scopolamine, ephedrine and their combination. Single intravenous dose of scopolamine 6 micrograms/kg (scopolamine hydrobromide 7.4 micrograms/kg) impaired various psychomotor functions both subjectively and objectively. It caused sedation, impairment of coordinative and reactive skills, visual disturbances and impairment of shortterm memory. Oral scopolamine hydrobromide in single doses of 0.3 mg and 0.9 mg, or 0.9 mg b.d. for 3 days, had few effects. A slight impairment of shortterm memory and a decrease in the flicker fusion threshold were seen. The visual nearpoint and pupil diameter were increased and some subjects reported blurred vision and dizziness during treatment with scopolamine 0.9 mg b.d. Scopolamine showed clear cardiovascular effects in all studies: it decreased heart rate and systolic blood pressure. Ephedrine alone and in combination with scopolamine had no deleterious effects. On the contrary, it antagonized the scopolamine-induced impairment in the flicker fusion test and the decrease in blood pressure and heart rate. In sufficient doses scopolamine impairs various psychomotor and cognitive skills. An oral dose of scopolamine hydrobromide 0.9 mg on average has few effects, although they may be very striking in certain individuals. To avoid unwanted effects and diminution in performance by scopolamine, doses less than 0.9 mg should be used.
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PMID:Psychomotor, physiological and cognitive effects of scopolamine and ephedrine in healthy man. 687 37

Patients with acquired forms of nystagmus may suffer from oscillopsia and blurred vision; abolishing or reducing nystagmus ameliorates these symptoms. Ideally, treatment of nystagmus should be directed against the pathophysiologic mechanism responsible. Identification of nystagmus pattern is important in directing therapy and occasionally requires electronic eye movement recording for precise characterization. Patients with acquired pendular nystagmus, particularly those with multiple sclerosis, often benefit from gabapentin, a drug with few side effects. Scopolamine, clonazepam, and valproate are also useful in some patients. A new drug, memantine, was effective in treating pendular nystagmus in one study, but it has not yet been approved for use in the United States. Periodic alternating nystagmus usually responds to baclofen. Central vestibular nystagmus, including downbeating and upbeating forms, can be treated with baclofen or clonazepam. In some patients, treatment of an underlying condition, such as periodic ataxia, Whipple's disease, and Chiari malformation, abolishes nystagmus and improves vision. If pharmacologic therapy fails, optical devices can be considered in selected patients. Injections of botulinum toxin and surgery to weaken extraocular muscles are prone to induce diplopia and may precipitate plastic-adaptive ocular motor changes that eventually negate the beneficial effect.
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PMID:Acquired Nystagmus. 1109 97

Hyoscine-N-butylbromide (Buscopan, Boehringer Ingelheim) is a widely used antispasmodic in radiological practice. There seems to be no consensus as to best practice within radiology regarding the precautions that need to be taken when prescribing Buscopan. We have performed a thorough review of the available literature and make the following recommendations to those administering Buscopan: (1) enquire whether there is an allergic history; (2) ensure patient literature warns that "in the rare event that following the examination you develop painful, blurred vision in one or both eyes, you must attend hospital immediately for assessment"; (3) warn patients to expect blurred vision and not to drive until this has worn off; (4) remind clinicians that special consideration needs to be given as to the method of investigating patients with cardiac instability, such as those recently admitted with acute coronary syndrome, recurrent cardiac pain at rest, uncontrolled left ventricular failure and recent ventricular arrhythmias.
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PMID:Precautions to be taken by radiologists and radiographers when prescribing hyoscine-N-butylbromide. 1855 31

Hyoscine N-butyl bromide, also known as scopolamine, is a type of antimuscarinic agent. This drug is associated with numerous common side effects, including abdominal fullness, constipation, urinary retention, blurred vision, skin flushing, tachycardia, decreased sweating, and salivation. The most unfavorable side effect is hemodynamic instability. In the present case, hypotension and acute myocardial infarction developed after intravenous hyoscine injection as a premedication therapy for colonoscopy. It was difficult to differentiate the cause-effect relationship between myocardial infarction and hypotension. Because both conditions were present under drug effects, we considered 2 possible diagnoses. One was coronary spasm with cardiogenic shock, and the other was myocardial ischemic sequela due to shock status. The latter diagnosis was confirmed after a series of examinations.
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PMID:Hyoscine-N-butyl-bromide-induced hypotension and myocardial ischemia. 2482 23

Black henbane (BH) or Hyoscyamus niger, has been used as a medicine since last centuries and has been described in all traditional medicines. It applies as a herbal medicine, but may induce intoxication accidentally or intentionally. All part of BH including leaves, seeds and roots contain some alkaloids such as Hyoscyamine, Atropine, Tropane and Scopolamine. BH has pharmacological effects like bronchodilating, antisecretory, urinary bladder relaxant, spasmolytic, hypnotic, hallucinogenic, pupil dilating, sedative and anti-diarrheal properties. Clinical manifestations of acute BH poisoning are very wide which include mydriasis, tachycardia, arrhythmia, agitation, convulsion and coma, dry mouth, thirst, slurred speech, difficulty speaking, dysphagia, warm flushed skin, pyrexia, nausea, vomiting, headache, blurred vision and photophobia, urinary retention, distension of the bladder, drowsiness, hyper reflexia, auditory, visual or tactile hallucinations, confusion, disorientation, delirium, aggressiveness, and combative behavior. The main treatment of BH intoxicated patients is supportive therapies including gastric emptying (not by Ipecac), administration of activated charcoal and benzodiazepines. Health care providers and physicians particularly emergency physicians and clinical toxicologists should know the nature, medical uses, clinical features, diagnosis and management of BH poisoning.
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PMID:Black henbane and its toxicity - a descriptive review. 2538 92