Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chemistry, pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage of ipratropium bromide are reviewed. Ipratropium bromide, a synthetic quaternary isopropyl derivative of atropine, interrupts vagally mediated bronchoconstriction by inhibiting the cyclic guanosine 3',5'-monophosphate system at parasympathetic nerve endings. Ipratropium bromide is poorly absorbed after oral and inhaled administration but diffuses rapidly into tissue after i.v. or i.m. administration. The elimination half-life is 3.2-3.8 hours. After inhalation, the drug is eliminated in the urine and feces. The bronchodilatory effect of ipratropium bromide in stable chronic obstructive pulmonary disease appears to be comparable, and may be superior, to that of the beta-sympathomimetic agents. In acute exacerbations, ipratropium bromide is useful but may not be the preferred agent because of a delayed onset of action (within 15 minutes; mean dose-dependent duration of effect, three to five hours). Combination therapy with other bronchodilating drugs has proved useful. Ipratropium bromide may be a useful adjunctive agent in the treatment of asthma. Since the onset of action is delayed, ipratropium bromide should not be used as single-drug therapy in an acute asthmatic exacerbation. Reported adverse effects, including cough, nausea, palpitations, dry mouth, nervousness, gastrointestinal distress, and dizziness, have been mild. The usual dosage is two inhalations (36 micrograms) four times daily, and the maximum number of doses per day should not exceed 12. Although ipratropium bromide is currently indicated only for maintenance therapy in stable chronic bronchitis and emphysema, it may be useful as adjunctive therapy in asthma and in the management of acute exacerbations of chronic bronchitis and asthma. Additional experience in a variety of chronic obstructive pulmonary disorders will help to clarify the role of ipratropium bromide in the treatment of obstructive pulmonary disease.
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PMID:Use of ipratropium bromide in obstructive lung disease. 297 9

A health survey was conducted on 199 workers engaged in dividing and packaging pyrethroids. The subjects were exposed to fenvalerate at 0.012-0.055 mg/m3 and deltamethrin at 0.005-0.012 mg/m3 in the air with simultaneous skin contact for 0.5-4.5 months. Burning sensations and tightness or numbness on the face appeared in two thirds of the subjects and one third had sniffs and sneezes. Abnormal facial sensations, dizziness, fatigue, and miliary red papules on the skin were more evident in summer than in winter. Neither abnormalities in other organs or systems nor symptoms or signs of acute pyrethroid poisoning were found by interviews, examinations, and laboratory tests. There was no significant difference in plasma levels of NA, cAMP, and cGMP between the examined subjects and the control group. The urine concentration of fenvalerate in the study group ranged from 1.02 to 18.6 micrograms/l; deltamethrin in the urine was present in trace amounts.
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PMID:Effects of pyrethroid insecticides on subjects engaged in packaging pyrethroids. 341 21

The effects of a continuous i.v. infusion of urodilatin at a dose of 30 ng kg-1 min-1 were studied in a patient with congestive heart failure. After 30 min, urodilatin had induced a marked stimulation of plasma cyclic GMP concentrations. In parallel haematocrit increased. No significant diuresis and no change of invasive haemodynamics was observed. After 2 h the patient developed a profuse perspiration. Eighty minutes later he suffered from dizziness due to hypotension (blood pressure 80/40 mmHg) and a sudden bradycardia (50 bpm). Urodilatin was discontinued and symptoms were relieved by bed tilt and rapid infusion of isotonic saline solution. Mechanisms contributing to these adverse effects may be fluid extravasation to the third space and sympathoinhibitory effects known to occur with natriuretic peptide infusion.
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PMID:Severe hypotension and bradycardia after continuous intravenous infusion of urodilatin (ANP 95-126) in a patient with congestive heart failure. 760 Dec 4

Ibudilast, a mixed phosphodiesterase (PDE) 3/4 inhibitor, is a cerebral vasodilator widely used in Japan for treating post-stroke dizziness. However, little studies have been conducted on the vasorelaxant effects of PDE inhibitors in the vertebrobasilar artery associated with dizziness onset. The in vitro vasorelaxant properties of ibudilast were, therefore, investigated by comparing with known selective PDE inhibitors, using vertebrobasilar arteries. Vasorelaxant activities of PDE3, PDE4, PDE5 inhibitors, and ibudilast were assessed in 5-hydroxytryptamine precontracted ring preparations from rabbit intracranial and extracranial vertebrobasilar arteries. Ibudilast more selectively relaxed the intracranial than extracranial artery. Similarly, selective PDE3 and PDE4 inhibitors showed higher selectivity for intracranial arteries. Furthermore, like selective PDE4 inhibitor, the vasorelaxation by ibudilast accompanied by increase in cAMP levels was inhibited by the adenylyl cyclase inhibitor SQ22536 in intracranial arteries. Next, it was examined whether nitric oxide (NO)/cGMP signaling is involved in this vasorelaxation in intracranial arteries. The suppression of NO/cGMP signaling by an NO synthase inhibitor or a guanylyl cyclase inhibitor potentiated the vasorelaxion by a PDE3 inhibitor and reduced that by a PDE4 inhibitor, while either suppression of the signaling had little influence on that by ibudilast. These results suggest that ibudilast has the high vasoselectivity for intracranial artery based on a mixed PDE3 and PDE4-inhibition, and effectively relaxes intracranial arteries independently of NO/cGMP signaling because of its vasorelaxation compensated by either PDE3- or PDE4-inhibition depending on the state of NO/cGMP signaling change.
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PMID:Ibudilast, a mixed PDE3/4 inhibitor, causes a selective and nitric oxide/cGMP-independent relaxation of the intracranial vertebrobasilar artery. 2103 26