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 value of 24-hour ambulatory monitoring of the ECG for the diagnosis of symptoms of dizziness, palpitations and syncope is controversial. In this study results from a hospital-based, clinical service have been analysed. Of 1,000 consecutive dynamic electrocardiograms (DCG), 678 were performed for assessment of dizziness, syncope or palpitations in 405 patients. 36 of the patients had pacemakers. 60 DCGs were technically inadequate. The recordings were classified according to the correspondence between DCG findings and symptoms noted in the patient diary: (I) Completely diagnostic: significant arrhythmias (SA) corresponding to diary symptoms - 99 recordings. (II) Incompletely diagnostic: (a) absence of SA in the presence of diary symptoms - 90 recordings; (b) presence of SA but no diary symptoms - 197 recordings; (c) presence of SA corresponding to symptoms other than that for which the DCG was indicated - 52 recordings. (III) Non-diagnostic: absence of both SA and diary symptoms - 180 recordings. Incompletely diagnostic categories were regarded as clinically valuable in that they either excluded a cardiac arrhythmia as a cause of symptoms (group IIa) or they revealed SA which did not correspond to diary symptoms (group IIc). The absence of symptoms corresponding to SA was ascribed to poor diary keeping in 54 of 197 recordings. These results are discussed in the context of the findings in normal and symptomatic patients. A clinical 24-hour ambulatory ECG monitoring service provided useful diagnostic information in 65% of recordings and 74% of patients.
Biotelem Patient Monit 1978
PMID:Arrhythmias in ambulatory persons. A review and experience of 1,000 consecutive recordings. 75 24

We report four cases of carbamazepine toxicity in children associated with the concurrent administration of erythromycin. They all developed clinical toxicity (ataxia, dizziness, nausea, and vomiting) when erythromycin administration was begun; symptoms disappeared after erythromycin was discontinued. Serum carbamazepine levels were measured before, during, and, in most cases, after the toxic episodes. In all cases, there was a sharp increase in carbamazepine concentration after erythromycin therapy was begun and a rapid fall once erythromycin was discontinued. Our data support the previous suggestion that erythromycin interferes with the liver microsomal metabolism of carbamazepine with a subsequent increase in blood levels of the drug.
Ther Drug Monit 1983
PMID:Carbamazepine--erythromycin interaction leading to carbamazepine toxicity in four epileptic children. 665 14

The steady-state pharmacokinetic profile of isosorbide-5-mononitrate (5-ISMN) after oral administration of an extended-release tablet formulation of 5-ISMN 60 mg or 120 mg once a day was compared with that after administration of isosorbide dinitrate (ISDN) 40 mg every 6 hours, in a randomized, open-label, three-way crossover trial in 24 healthy men. After oral administration of extended-release 5-ISMN 60 mg or 120 mg once daily, 5-ISMN was slowly absorbed, reaching mean peak plasma concentrations of 557 and 1151 ng/mL, respectively, in approximately 3 hours. Plasma concentrations of 5-ISMN were dose proportional between 60 mg and 120 mg. After oral administration of ISDN 40 mg every 6 hours, a mean peak plasma 5-ISMN concentration of 806 ng/mL was achieved in less than 2 hours (mean time to reach the maximum plasma concentration was 1.5 hours). The mean plasma apparent elimination half-life of 5-ISMN was 6.2 hours after extended-release 5-ISMN administration and 7.1 hours after ISDN. Although the maximum plasma concentration was higher and the minimum plasma concentration was lower after administration of extended-release 5-ISMN 120 mg once daily compared with ISDN 40 mg every 6 hours, there was no significant difference (P > 0.05) in the "bioavailability" of 5-ISMN between these two treatments. The most commonly reported adverse events in these "nitrate-naive" subjects were headache, dizziness, nausea, and vomiting; these were dose related and their incidence decreased with repeated exposure.
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PMID:Pharmacokinetics of isosorbide-5-mononitrate after oral administration of an extended-release mononitrate formulation versus a standard dinitrate formulation. 761 24

We tested the hypothesis that resolution versus persistence of symptomatic ischaemia and/or development of nausea/dizziness on the third day of loading with perhexiline maleate (PM), is correlated with perhexiline plasma concentrations after the standard loading phase in patients with acute coronary syndromes. Forty consecutive patients with either unstable angina pectoris or non-Q-wave myocardial infarction with persistent angina pectoris, despite maximal pharmacological therapy (other than PM), were studied. All patients received PM 400 mg/day for 3 days and 200 mg/day thereafter. On days 2 and 3 observers blinded to the 72-96 h plasma perhexiline concentration assessed the patient regarding episodes of angina and/or nausea/dizziness. On the third day of loading with PM, 12 patients experienced angina and 11 patients had nausea and/or dizziness. Plasma perhexiline concentrations at 72-96 h varied widely: mean 0.46 +/- 0.26 (range 0.11-1.77) microgram/ml. There was a relationship of borderline statistical significance between resolution of anginal symptoms and plasma perhexiline concentration > 0.15 microgram/ml (p = 0.055). There was a close relationship between emergence of nausea/dizziness with plasma perhexiline concentration > 0.06 microgram/ml (p < 0.01). We conclude that this study (a) suggests that PM exerts incremental antianginal effects over those of other antiischaemic agents in patients with acute coronary syndromes and (b) establishes that the development of nausea and/or dizziness in such patients is strongly predictive of accumulation of perhexiline beyond the therapeutic range of the drug.
Ther Drug Monit 1996 Dec
PMID:Relationship between plasma perhexiline concentration and symptomatic status during short-term perhexiline therapy. 894 58

Sirolimus is a new immunosuppressive drug that has been evaluated in animal experiments. The current study was conducted on humans with reformulated sirolimus in doses from 3 mg/m2 to 15 mg/m2. Sixteen renal transplant recipients were included in this phase I study to determine the safety, tolerance, and preliminary pharmacokinetics of increasing single doses of orally administered sirolimus. All 16 patients had stable renal graft function after a renal transplant at least 6 months before the study. Basal immunosuppression consisted of cyclosporine and prednisolone (n = 10) or cyclosporine, azathioprine, and prednisolone (n = 6). Four groups (I, 3 mg/m2; II, 5 mg/m2; III, 10 mg/m2; IV, 15 mg/m2) of four patients were assigned randomly to receive sirolimus (n = 3) or placebo (n = 1). Among the 12 patients who received sirolimus, five had mild transient study events such as headache, nausea, mild dizziness, hypoglycemia, epistaxis, and decrease in platelets. No serious adverse events occurred and no nephrotoxic effects could be related to the single dose administration of sirolimus. The only study event that was judged as probably related to sirolimus was the single case of thrombocytopenia. The other events were evaluated as possibly related. Thrombocytopenia occurred at the highest dose level (15 mg/m2 sirolimus). In two of the patients in the placebo group, slight elevations of liver enzymes and serum amylase were seen. Blood and plasma sirolimus concentrations were analyzed by an electrospray-high performance liquid/mass spectrophotometric (ESP-HPLC/MS) method Sirolimus showed an extensive red blood cell distribution with a mean blood/ plasma ratio of 49.1. The elimination half-life ranged from 43.8 to 86.5 hours (mean 56.9 hours). The Cmax and the area under the concentration versus time curves (AUC) correlated reasonably with doses from 3 to 15 mg/m2. The oral dose clearance ranged from 42 to 339 ml/h.kg. No clinically significant differences were seen in the trough concentrations of cyclosporine or the AUCs before and after the administration of sirolimus. Administration of single oral doses of sirolimus from 3 to 15 mg/m2 was safe and well tolerated in stable renal transplant recipients. Thrombocytopenia may be the dose-limiting toxicity. Additional phase II and phase III clinical trials will define the immunosuppressive efficacy of sirolimus.
Ther Drug Monit 1997 Aug
PMID:Kinetics and dynamics of single oral doses of sirolimus in sixteen renal transplant recipients. 926 80

The objective of this retrospective study was to report on the clinical presentation, etiology, and laboratory tests of both chronic and acute atrial fibrillation (AF) admitted to the cardiology unit of a teaching hospital in southern Saudi Arabia. We studied 219 records; 132 (60.3%) and 87 (39.7%) had documented chronic AF (group 1), and acute AF (group 2) respectively. The mean age (SD) was significantly higher in group 1 (64.6 [SD 19.4] vs 52.9 [SD 15.6]) (P<0.001). Palpitation, dizziness and syncope were the most frequent symptoms in acute AF, while dyspnea was the most common presentation in the chronic type. On the other hand, heart failure and embolic complications were reported significantly in group 1, but the frequency of acute respiratory problems and acute myocardial infarction was similar in both groups. The most common causes of both types of AF were rheumatic valvular diseases (26%), IHD (24.2%), hypertension (23.7%), and lung diseases (13.2%); however, in 28 patients (12.8%) no cause was detected. The echocardiography findings of chamber dilatation, valve lesions, and depressed left ventricular function were significantly frequent in group 1 (P<0.01). Although rheumatic valvular diseases are still common in Saudi Arabia, ischemic heart disease and hypertension are emerging as important causes of AF in this developing nation, and therefore require prevention and control.
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PMID:Patterns of atrial fibrillation at a regional hospital in Saudi Arabia. 992 6

A 57-year-old man consulted an herbalist for epigastric discomfort. Four hours after he drank a decoction made from 14 herbs, he developed nausea, epigastric pain, and dizziness. He also had two loose bowel movements. On arrival at the hospital 4 hours later, his blood pressure was 77/46 mm Hg, and his pulse was 60 beats/min. He was given intravenous fluids. In the next 3 hours, his blood pressure gradually returned to his usual level of 100/65 mm Hg. His other gastrointestinal symptoms gradually subsided during the next 24 hours. His white cell count was 17.8 x 109/L but was normal on recheck. Complete cell counts, renal function and liver function tests, and electrocardiogram were otherwise normal. He was discharged home on day 2. Seven of the 14 herbs taken by this patient are known to have vasodilatory or blood pressure-lowering effects, and 3 of these herbs are used to manage hypertension. In traditional Chinese medicine, practitioners often use a combination of herbs in an attempt to improve the efficacy but reduce the adverse effects of treatment. The risk of adverse herbal interactions will also be higher.
Ther Drug Monit 2003 Jun
PMID:Adverse herbal interactions causing hypotension. 1276 56

Drugs with long terminal half-lives, such as terbinafine, have a potential for involvement in both long-lasting drug-drug interactions and interactions appearing weeks after discontinuation. We present a case report on a 37-year-old white woman with normal CYP2D6 metabolic capacity who was treated with amitriptyline, valproate, and olanzapine when terbinafine was introduced. Shortly thereafter she experienced extreme dryness of the mouth, nausea, and dizziness accompanied by a large increase in the serum concentrations of amitriptyline and nortriptyline. Terbinafine therapy was discontinued, and the amitriptyline dose was reduced. Surprisingly, the serum concentrations of amitriptyline and nortriptyline did not return to baseline until approximately 6 months later. Studies have shown that terbinafine is a highly potent competitive inhibitor of CYP2D6. CYP2D6 is an important intermediate enzyme in metabolism of amitriptyline to nortriptyline. Nortriptyline is further metabolized to 10-hydroxy metabolites, mainly by CYP2D6. It is, therefore, likely that the concomitant use of terbinafine was the major cause of the increased serum concentrations of amitriptyline and nortriptyline. Very different terbinafine elimination half-lives (17-400 hours) are stated in the physicians' reference guides. If the shortest estimates are used when adjusting the dose of interacting drugs, the risk of underestimating the duration of the interaction is large. Based on our data there is a risk of clinically significant drug-drug interactions for at least 3 months after stopping terbinafine intake.
Ther Drug Monit 2005 Oct
PMID:Prolonged pharmacokinetic drug interaction between terbinafine and amitriptyline. 1617 44

This case report highlights a rare adverse drug reaction caused by levofloxacin, resulting in optic neuritis progressing into unilateral loss of vision. A 49-year-old male patient was diagnosed to suffer from left maxillary and ethmoid sinusitis and was only prescribed oral levofloxacin 500 mg tablets once daily for 5 days. Within a few minutes after taking the first dose of the drug, the patient experienced respiratory distress, dizziness, confusion with pain, and loss of color vision, followed by almost complete loss of vision in the right eye. The left eye was normal. After ophthalmologic examinations and investigations, he was diagnosed to suffer from optic neuritis, probably (according to Naranjo adverse drug reaction probability scale) induced by levofloxacin.
Ther Drug Monit 2012 Apr
PMID:Oral levofloxacin-induced optic neuritis progressing in loss of vision. 2237 42

We describe a patient who developed symptoms of headache, fatigue, and dizziness after administration of terbinafine (Lamisil). Laboratory tests revealed that he is heterozygous for the C677T variation of the methylenetetrahydrofolate reductase genetic mutation. The prescription of Deplin (L-methylfolate) greatly reduced the symptoms. It was later noted that Lamisil's mechanism of action interferes with cells' methylation cycle, which we suspect compromises cellular function in people with the methylenetetrahydrofolate reductase genetic mutation.
Ther Drug Monit 2015 Dec
PMID:Antifolates and MTHFR. 2592 15


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