Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dimebon, launched earlier in Russia as an antihistamine drug, was evaluated as a representative of a new generation of anti-Alzheimer's drugs that have two beneficial actions: (1) to alleviate symptoms, and (2) to prevent progression of the disease. The drug demonstrated cognition and memory-enhancing properties in the active avoidance test in rats treated with the neurotoxin AF64A, which selectively destroys cholinergic neurons. Dimebon protected neurons in the cerebellum cell culture against the neurotoxic action of beta-amyloid fragment (A beta 25-35, EC50 = 25 microM). In vitro, Dimebon displayed Ca(2+)-blocking properties (IC50 = 57 microM, on isolated rat ileum intestine) and pronounced anticholinesterase activity (IC50 = 7.9 microM and 42 microM for butyrylcholine esterase and acetylcholine esterase, respectively). It also exhibited strong anti-NMDA activity in the prevention of NMDA-induced seizures in mice (EC50 = 42 +/- 6 mg/kg i.p.). A beneficial effect of Dimebon in the therapy of Alzheimer's disease was demonstrated in a pilot clinical trial performed in the Moscow Center of Gerontology. Fourteen patients who participated in the trial were evaluated for their state of personality and for the severity of the disease. The evaluation included orientation (space, place, time, and patient personality), memory for the past and present, life in present, speech, irritability, and so forth. During and after the eight-week therapy with Dimebon, cognitive and self-service functions of patients improved significantly, and psychopathic symptoms, anxiety, depression, tearfulness, and headache were substantially diminished. The results of these studies suggest Dimebon as a new candidate for the therapy of Alzheimer's-like disorders.
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PMID:Antihistamine agent Dimebon as a novel neuroprotector and a cognition enhancer. 1146 98

Aster scaber T. (Asteraceae) has been used to treat bruises, snakebite, headache, and dizziness in traditional Chinese medicine. In the present study, the neuroprotective effect of four quinic acid derivatives from A. scaber on amyloid Abeta-induced PC12 cell toxicity was investigated. When cells were treated with quinic acid derivatives prior to Abeta, cell toxicity was significantly diminished. Among quinic acid derivatives, (-)4,5-dicaffeoyl quinic acid (1) gave the highest protection against Abeta-induced cell toxicity. In addition, the neurotrophic effects of compounds were evaluated by microscopically monitoring their potency to induce neurite outgrowth in PC12 cells. Four quinic acid derivatives from A. scaber promoted neurite outgrowth in PC12 cells. Interestingly, a novel quinic acid, (-)3,5-dicaffeoyl-muco-quinic acid (2) was more effective than the other compounds in promoting neurite outgrowth. Unlike nerve growth factor, the withdrawal of quinic acids did not result in any significant decrease in cell viability. The results suggest that quinic acid derivatives from A. scaber might potentially be used as a therapeutic agent in Alzheimer disease.
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PMID:Neuroprotective and neurotrophic effects of quinic acids from Aster scaber in PC12 cells. 1151 Apr 86

The tolerability and safety of donepezil HCI in patients with mild to moderate Alzheimer's disease (AD) were examined in an integrated analysis of phase II/III placebo-controlled trials. Patients with mild to moderately severe AD (n=1,920) were randomised to receive donepezil (n=1,291) or placebo (n=629). Adverse events, physical examinations and clinical laboratory tests were assessed. A high completion rate (79%) was achieved in these trials. Of the 1,291 patients receiving donepezil only, 142 (11%) withdrew because of an adverse event compared with 43 of the 629 (7%) placebo patients. The most common adverse events included nausea, diarrhoea, headache, insomnia, dizziness, rhinitis, vomiting, asthenia/fatigue and anorexia. Donepezil had no clinically significant effect on any laboratory evaluations and was not associated with hepatotoxicity. These results demonstrate that donepezil is well tolerated and has a favourable safety profile at clinically effective, once-daily doses of 5 mg and 10 mg.
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PMID:Donepezil: tolerability and safety in Alzheimer's disease. 1246 88

Treatment of Alzheimer's disease sometimes uses combinations of drugs because dementia is frequently associated with behavioral symptoms. Risperidone and donepezil are both metabolized through cytochrome P450 2D6 and 3A4, raising the possibility of drug interactions with combination therapy. The objective of this study was to determine whether significant drug interactions occur with concomitant administration of donepezil and risperidone. In an open-label, three-way crossover study, 24 healthy men were randomly assigned to receive 0.5 mg of risperidone twice daily, 5 mg of donepezil once daily, or both drugs for 14 consecutive days, followed by a 21-day washout period. The treatment ratios of AUC and associated 90% confidence intervals (CIs) for risperidone active moiety, defined as risperidone plus 9-hydroxyrisperidone (ratio = 110.2%; 90% CI = 103.7-117.2), and for donepezil (ratio = 97.1%; 90% CI = 90.0-103.6) were within the 80% to 125% of bioequivalence range. The treatment ratios of Cmax and associated 90% CIs for risperidone active moiety (ratio = 114.6%; 90% CI = 107.0-122.8) and for donepezil (ratio = 96.1%; 90% CI = 90.0-102.6) were also within the bioequivalence range. Therefore, no significant pharmacokinetic differences occurred in either risperidone active moiety or donepezil when given alone or in combination. Adverse events (predominantly headache, nervousness, and somnolence) were minor and comparable for all treatment groups. The results indicate that no clinically meaningful drug interactions occurred between risperidone 1 mg daily and donepezil 5 mg daily at steady state, and therefore no dosage adjustment is required when both drugs are combined with the dosage regimen studied. Additional investigations are warranted to determine the potential for interactions in elderly patients with dementia who may eliminate risperidone and donepezil more slowly and thus be more vulnerable to clinical drug interactions than the young healthy subjects examined in this study.
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PMID:Pharmacokinetic and safety assessments of concurrent administration of risperidone and donepezil. 1261 71

Memantine, an uncompetitive antagonist with moderate affinity for NMDA receptors, demonstrates voltage-dependency and relatively fast on/off receptor kinetics. Memantine 20 mg/day significantly slowed the rate of deterioration in outpatients with moderate to severe Alzheimer's disease in a 28-week US randomised, double-blind, placebo-controlled, multicentre study. Memantine 10 mg/day improved measures of dementia in care-dependent inpatients with Alzheimer's disease or vascular dementia in a 12-week randomised, double-blind study. Significantly more memantine than placebo recipients were responders according to Clinical Global Impression of Change scores and the Behavioural Rating Scale for Geriatric Patients Care Dependence subscale. Memantine 20 mg/day significantly improved cognition-related outcomes (cognitive subscale of the Alzheimer's Disease Assessment Scale) in patients with vascular dementia in two 28-week randomised, double-blind, placebo-controlled, multicentre trials. No statistically significant between-group difference was seen in other primary endpoints. Adverse events (incidence in memantine recipients greater than in placebo recipients) occurring in patients with moderately severe to severe dementia included diarrhoea, insomnia, dizziness, headache and hallucination.
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PMID:Memantine. 1271 Aug 65

The objective of this study was to evaluate the safety, tolerability, maximum tolerated dose, pharmacokinetics, and pharmacodynamics of five fixed doses of ganstigmine (CHF 2819) in patients with probable Alzheimer's disease (AD). This randomized, double-blind, placebo-controlled trial evaluated five dose levels (5, 7.5, 10, 12.5, and 15 mg) administered orally once daily for 7 days. Adverse events and continuous telemetry were collected on successive panels of six patients (five active, one placebo). Acetylcholinesterase, butyrylcholinesterase, and plasma drug levels were measured. A total of 29 patients were randomized and 18 completed the study. A total of seven patients, including five of five in the 12.5-mg panel, discontinued because of adverse events. Four patients were withdrawn administratively from the first panel while an episode of atrial fibrillation (the only serious adverse event) was investigated. This panel was then repeated. Mild, transient headache or nausea were the most commonly reported adverse events. Multiple moderate adverse events in the 12.5-mg panel (including nausea, vomiting, and anorexia) led to the decision not to proceed with a 15-mg panel. Ten milligrams was determined to be the maximum tolerated dose. Ganstigmine exhibited nonlinear pharmacokinetics, was absorbed rapidly, and reached peak concentrations within 1 hour. Acetylcholinesterase inhibition was dose dependent and lasted as long as 24 hours. Ganstigmine, a novel cholinesterase inhibitor, was well tolerated within a dosing range of 5 to 10 mg. Once-daily dosing is supported by data on acetylcholinesterase inhibition.
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PMID:First clinical evaluation of ganstigmine in patients with probable Alzheimer's disease. 1278 20

Previous epidemiological and clinical studies of humans exposed to polychlorinated biphenyls (PCBs) indicate that the majority of patients have neurological complaints (e.g., headache, vertigo, paresthesias, poor memory and concentration, fatigue, depression). Since only a small minority of PCB-exposed patients demonstrate abnormalities on objective neurological measures (e.g., CT-scans, EEC, nerve conduction velocity), it is particularly unfortunate that objective neuropsychological data has not been published to substantiate patient complaints. The present study provides neuropsychological test data on two patients exposed to PCBs. In both cases, PCB exposure is documented by an analysis of PCB levels in the patients' work environments. Despite the absence of abnormalities on CT-scans and EEC, both patients displayed a variety of cognitive deficits and emotional disturbance. Serial assessment of one patient with high blood levels of PCBs revealed a dementia (sharing certain features with Alzheimer's disease) and an organic affective syndrome. Assessment of a second patient exposed to PCBs (but with no detectable blood levels of PCBs) suggested that his cognitive impairments were not due to PCB exposure. The present study provides data which points to the importance and sensitivity of neuropsychological examination in cases of PCB-exposure.
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PMID:Dementia as a neuropsychological consequence of chronic occupational exposure to polychlorinated biphenyls (PCBs). 1458 22

(1) The standard treatment for mild to moderately severe Alzheimer's disease is donepezil, an anticholinesterase with some beneficial effects (progression is slowed in about 10% of patients, by six months on average) and mainly gastrointestinal adverse effects. (2) Memantine, a drug first developed several decades ago, belongs to the family of NMDA glutamate receptor inhibitors. Marketing authorisation was recently granted for memantine in moderately severe and severe Alzheimer's disease. (3) The clinical evaluation dossier on memantine is poor. Marketing approval was obtained thanks to only one placebo-controlled trial. It included only 252 patients treated for 28 weeks. Patients with moderately severe Alzheimer's disease were not analyzed separately from those with severe forms, even though the response criteria are different for the two categories of patients. (4) According to the chosen endpoint, 5% to 19% of patients were clinically improved by memantine. It is not known whether this benefit persists beyond six months. (5) The report of a trial comparing memantine + donepezil with placebo + donepezil does not analyse the response rate. Use of this combination is not currently justified. (6) In clinical trials the main adverse effects of memantine were neurological (dizziness and headache). Fairly lengthy pharmacovigilance data from Germany are relatively reassuring. (7) In practice, donepezil remains the reference option for moderately severe Alzheimer's disease. Memantine is a second-line option, as its adverse effects differ from those of anticholinesterases. There is still no drug offering a clear benefit for patients with severe forms of the disease.
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PMID:Memantine: new preparation. Poor evaluation and uncertain benefit in Alzheimer's disease. 1498 82

Cerebral amyloid angiopathy is due to beta-protein accumulation in the vessel walls and occurs in normal aging, Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis. It causes intraparenchimal and subarachnoid bleeding with hemosiderin deposits and multiple infarcts presenting with headache, stroke and epilepsy. Such lesions may contribute to cognitive impairment. So far, no therapy is available. In future, amyloid in the vessel wall might be addressed by amyloid disaggregating drugs and amyloid antibodies.
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PMID:A beta-related cerebral amyloid angiopathy. 1504 8

Idiopathic or primary angiitis of the CNS (PACNS) and cerebral amyloid angiopathy (CAA) are unusual vasculopathies generally regarded as unrelated disorders. A few case reports have, however, described granulomatous angiitis in patients with sporadic, amyloid beta peptide (Abeta)-related CAA. Here we describe the clinical, neuroradiological and neuropathological features of nine patients with Abeta-related angiitis (ABRA). Combining these with the individual case reports drawn from the literature has allowed us to define ABRA as a clinical entity and to compare its features with those of PACNS. The mean age of presentation of ABRA (67 years) is higher than that of PACNS but lower than that of sporadic non-inflammatory Abeta-related CAA. Alterations in mental status (59%), headaches (35%), seizures and focal neurological deficits (24%) are common. Hallucinations are a presenting manifestation in 12% of cases. Most patients have white matter hyperintensities on MRI but these are of similar appearance to those in PACNS. Cerebrospinal fluid usually shows modest elevation of protein and pleocytosis. Neuropathology reveals angiodestructive inflammation, often granulomatous, and meningeal lymphocytosis. Abeta is consistently present in abundance in affected blood vessels but usually scanty within the parenchyma of the cerebral cortex. However, the cortex includes numerous activated microglia, occasionally in a plaque-like distribution and containing cytoplasmic Abeta. The cerebral white matter shows patchy gliosis and rarefaction, in some cases marked. Our findings (i) help to dissect one separate clinicopathological entity from what is likely to be a spectrum of primary angiitides of the CNS; (ii) have important therapeutic implications for one category of patients with amyloid-related vasculopathy; and (iii) may provide valuable insights into the development of amyloid-associated inflammation, of relevance not only to ABRA but also to Abeta-immunization-related encephalitis and to Alzheimer's disease.
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PMID:Abeta-related angiitis: primary angiitis of the central nervous system associated with cerebral amyloid angiopathy. 1565 28


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