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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Theophylline concentrations in saliva and serum were compared in 20 patients with essential tremor. There was a strong correlation between the concentrations in saliva and serum (r = 0.9, slope of 0.48). The ratio between unbound and bound theophylline as assessed by ultrafiltration was 0.30. This ratio was similar to that between theophylline concentrations in CSF and serum. The theophylline concentration in serum was not predictable from that obtained in saliva in individual cases. Moreover, the levels in saliva were about 20% higher than the unbound concentrations of theophylline in serum.
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PMID:Theophylline concentrations in serum, saliva, and cerebrospinal fluid in patients with essential tremor. 158 98

Twenty-one volunteers with moderate to severe asthma were exposed to sulfur dioxide (SO2) at concentrations of 0 (control), 0.3, and 0.6 ppm in each of three medication states: (1) low (much of their usual asthma medication withheld), (2) normal (each subject on his own usual medication schedule), and (3) high (usual medication supplemented by inhaled metaproterenol before exposure). Theophylline, the medication usually taken by subjects, was often supplemented by beta-adrenergics. Exposures were for 10 min and were accompanied by continuous heavy exercise (ventilation approximately 50 l/min). Lung function and symptoms were measured before and after exposure. With normal medication, symptomatic bronchoconstriction occurred with exercise and was exacerbated by 0.6 ppm SO2, as reported for mildly unmedicated asthmatics studied previously. Both baseline and post-exposure lung function were noticeably worse in the low-medication state. High medication improved baseline lung function and prevented most bronchoconstrictive effects of SO2/exercise. High medication also increased heart rate and apparently induced tremor or nervousness in some individuals.
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PMID:Responses to sulfur dioxide and exercise by medication-dependent asthmatics: effect of varying medication levels. 196 62

This parallel-group study compared the safety and efficacy of controlled-release albuterol versus sustained-release theophylline, both administered every 12 hours. One hundred twenty-four adolescent and adult patients with asthma and with chronic reversible obstructive airway disease were studied. All patients qualified with an FEV1 less than or equal to 80% of predicted (not receiving treatment) and greater than or equal to 15% reversibility in FEV1 or greater than or equal to 25% reversibility in FEF25-75% after inhaled isoproterenol. All patients were known to be able to take theophylline without unacceptable adverse effects. Theophylline was titrated for patients to receive, unblinded, theophylline serum concentrations of 10 to 20 micrograms/ml. With subsequent randomization, 62 patients continued to receive theophylline and 62 patients started taking albuterol in the 12-week, double-blind, double-dummy portion of the study. Pulmonary function was measured during a pretreatment visit (unmedicated) and serial assessment was made starting just before the morning dose and continuing for 12 hours after the dose at the end of 1, 6, and 12 weeks of treatment. Both treatment groups exhibited statistically significant increases in FEV1 from the pretreatment visit to all times of observation at weeks 1, 6, and 12. The increases in FEV1 were not significantly different between albuterol and theophylline administration. There was no evidence of tolerance to the bronchodilatory effect during 12 weeks in either treatment group. Only one patient in the study stopped treatment because of an adverse effect. This patient had tremor during albuterol administration. All other adverse events were tolerated or resolved during treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Long-term, double-blind comparison of controlled-release albuterol versus sustained-release theophylline in adolescents and adults with asthma. 217 67

Mice subjected to hypoxic stress resulted in increased respiratory rate, tremor and convulsions followed by death. The latencies for convulsion and death following hypoxic stress were 33.29 +/- 1.20 and 34.36 +/- 1.16 min, respectively. In the present study effects of adenosinergic agents Ro 5-4864, a "peripheral-type" benzodiazepine receptor agonist, and carbamazepine were studied on hypoxic stress-induced neurotoxicity. Adenosinergic agents such as adenosine, 2-chloroadenosine, N6-cyclohexyladenosine and dipyridamole increased the latencies for convulsions and death due to hypoxia. Theophylline (50 mg/kg i.p.), an adenosine receptor antagonist, reversed this protective effect of adenosinergic agents. Pretreatment with Ro 5-4864 (10, 20 mg/kg i.p.) also offered theophylline (50 mg/kg, i.p.)-sensitive protection against hypoxic stress. Similarly, carbamazepine treatment (10-30 mg/kg, i.p.) significantly prolonged the latencies for convulsion and death following hypoxic stress. Prior treatment with theophylline (50 mg/kg, i.p.) reversed this protective effect of carbamazepine, indicating the possible involvement of adenosinergic mechanism in the observed protective effect of carbamazepine. These results indicate that the adenosinergic mechanism may be responsible for the observed neuroprotective effect of these agents against hypoxia.
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PMID:The protective effect of adenosinergic agents, Ro 5-4864 and carbamazepine against hypoxic stress-induced neurotoxicity in mice. 231 49

1. The effect of intravenous aminophylline on theophylline-induced tremor were studied in six hyperthyroid patients before and after treatment to euthyroidism. 2. Baseline tremor power was significantly greater in the hyperthyroid compared with the euthyroid state (P less than 0.05). 3. Aminophylline produced a significantly greater increase in tremor power in the hyperthyroid compared with euthyroid state. 4. There was a significant increase in plasma theophylline clearance and reduction in t1/2 elimination when patients were hyperthyroid but volume of distribution did not change. 5. Intravenous aminophylline potentiates the tremor produced in hyperthyroidism despite an increase in plasma theophylline clearance. A pharmacodynamic mechanism is therefore likely.
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PMID:The effect of theophylline on thyrotoxic tremor. 277 8

20 children (age range 0.8-14.7 years) with acute severe asthma were alternately randomized to receive one of two different treatment regimes. 10 children (control-group) received Salbutamol inhalation (75 micrograms/kg in 2 ml Saline every two hours). 10 children (reproterol-group) received reproterol infusion (0.2-2.0 micrograms/kg/min in Saline) and inhaled Saline only. Other therapy regimen were identical in both groups: Theophylline infusion, i.v. Prednisolone, adequate fluids intake and oxygen insufflation. Age, severity and maintenance therapy of asthma, and severity of the acute episode, were not significantly different in both groups. Treatment efficacy, assessed with a simple clinical score, the heart and respiratory rates, the peak expiratory flow (PEF) and the blood gases, was comparable in both groups. Side effects, i.e. tachycardia, blood pressure changes and tremor, were also similar and clinically not relevant in both groups. In two children, who previously needed repeated mechanical ventilation, severe respiratory failure could be successfully controlled only when the reproterol dose was raised 10 folds (2.0 micrograms/kg/min). Reproterol infusion can be recommended in children with acute severe asthma, who do not respond satisfactorily to current therapy regimen, particularly in children who previously experienced numerous intubations.
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PMID:[Intravenous infusion of reproterol (a beta-2-mimetic agent) in the therapy of severe asthma attacks in childhood]. 308 54

Theophylline, with its narrow therapeutic margin, is a common cause of iatrogenic and deliberate overdose. Most cases of self-poisoning are with sustained release preparations, with peak concentrations occurring up to 12 or more hours after overdose. Toxic symptoms are often seen at concentrations above 15 mg/L. Theophylline is metabolised within the cytochrome P-450 system, with an average total body clearance of 50 to 60 ml/min. Clearance is, however, affected by many factors such as other drugs or disease, and in overdose zero order kinetics may result in prolonged half-lives. Toxicity is characterised by agitation, tremor, nausea, vomiting, abdominal pains, seizures, and tachyarrhythmias. Hypokalaemia and metabolic acidosis are more profound in acute toxicity, and hypercalcaemia is usually present. Seizures occur at lower concentrations after chronic over-medication than after acute overdose. Gastric lavage should be performed in all patients presenting early, and an oral multiple dose charcoal regimen started with 50 to 100g charcoal, repeating with 50g doses and checking theophylline concentrations at 2- to 4-hour intervals. Multiple dose charcoal can be expected to double the clearance of theophylline, being as effective as a haemodialysis. Of the invasive techniques available, charcoal haemoperfusion is the most effective, increasing clearance 4- to 6-fold. Supportive care is particularly important. The aggressive supplementation of potassium, treatment of emesis with droperidol and ranitidine, and treatment of tachyarrhythmias and hypotension (possibly with propranolol), together with oral multiple dose charcoal may obviate the need for haemoperfusion. Seizures suggest increased morbidity and mortality. Charcoal haemoperfusion should be considered if plasma concentrations are greater than 100 mg/L in an acute intoxication or greater than 60 mg/L in a chronic intoxication. The decision to haemoperfuse should not be based on plasma concentrations alone, but an overall evaluation of the patient's laboratory and clinical status.
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PMID:Role of extracorporeal drug removal in acute theophylline poisoning. A review. 330 69

The objectives of this study were to establish a suitable and validated in vitro bioassay of piscine gonadotropins (GTHs) by using a carp testis androgen production system and to compare the androgenic responses in such an assay to gonadotropins from various vertebrate species. The testes from mature carp with gonadosomatic indices of 8-30% were used. Androgen production was first compared with respect to methods for preparation of the carp testis (sliced, minced, homogenized, and collagenase-dispersed testis preparations). The time course of androgen formation, the effects of xanthine and theophylline, and other factors on androgen production also were investigated. Theophylline was more effective than xanthine in potentiation of gonadotropin-evoked androgen formation by carp testis. The testis preparations were incubated in medium 199 (pH 7.40) containing 2 mM theophylline with shaking at 100 cycles/min at 25 degrees C for 4 hr. Homogenized testis preparations had limited ability for androgen production, while sliced, minced, and minced-collagenase-dispersed testis preparations were highly responsive to gonadotropins for androgen production. The minced testis preparation, utilizing 100 mg/ml incubation medium per vial, was chosen as the standard incubation procedure in this study. The minced testis androgen production assay was highly sensitive to gonadotropins from several piscine species (silver carp, common carp, and salmon), and all these GTHs produced parallel dose-related androgen production curves. Mammalian GTHs were also capable of promoting androgen formation by carp testis, but they were much less potent than were piscine GTHs. Pregnant mares' serum gonadotropin (PMSG) was more effective than human chorionic gonadotropin (hCG) in evoking carp testis androgen production.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Species variation of gonadotropic activity in an in vitro assay measuring androgen formation by carp (Cyprinus carpio) testis with special reference to bioassay of piscine gonadotropins. 377 Apr 34

A single intravenous administration of theophylline as aminophylline at 10 mg/kg to four mares induced a diuresis in which maximal urine production was more than seven times the control volume. The diuretic effect was maximal within the first hour post-administration, and lasted approximately 6 h. Theophylline resulted in dose-related tachycardia, polypnoea and nervous symptoms (tactile, visual and auditory hypersensitivity, muscle tremor, sweating) in normal mares, but had only minor effects on arterial and central venous blood pressures, intrapleural pressure, red blood cell variables and plasma proteins. The upper limit of safe plasma theophylline concentration in horses is approximately 15 micrograms/ml. Whenever feasible, the oral or intragastric route of administration should be used as it is safer than the intravenous route.
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PMID:Some dynamic and toxic effects of theophylline in horses. 405 50

In-vitro studies on human bronchial and skeletal muscle indicate that a combination of theophylline and adrenergic beta 2-stimulants might give a potentiated therapeutic effect with fewer side effects, such as tremor, than treatment with beta 2-stimulants alone. In-vivo studies in asthmatics showed that pretreatment with oral bronchodilating doses of theophylline and terbutaline potentiated the effect of terbutaline given by inhalation. Oral doses of theophylline or a beta 2-adrenostimulant combined with beta 2-stimulants by aerosol therefore seem to be an effective form of treatment. The choice of oral treatment depends on the side effects. Theophylline in slow-release formulation might have advantages over oral beta 2-stimulants in children and young adult asthmatics. In patients with tremor problems, theophylline would also appear preferable: a combination of low oral doses of theophylline and beta 2-adrenostimulants have better bronchodilation with less skeletal muscle tremor than a higher dose of beta 2-adrenostimulants by mouth alone and perhaps have advantages in elderly asthmatics.
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PMID:In-vitro and in-vivo effects of theophylline and beta 2-adrenostimulants in combination. 610 28


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