Oxidation of dopamine and related catechols in dopaminergic brain regions in Parkinson's disease and during ageing in non-Parkinsonian subjects.

The present study was performed to examine if catechol oxidation is higher in brains from patients with Parkinson's disease compared to age-matched controls, and if catechol oxidation increases with age. Brain tissue from Parkinson patients and age-matched controls was examined for oxidation of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylalanine (DOPA) to corresponding quinones, by measurement of 5-S-cysteinyl-dopamine, 5-S-cysteinyl-DOPAC and 5-S-cysteinyl-DOPA. The cysteinyl catechols are assumed to be biomarkers for DA, DOPAC and DOPA autoxidation and part of the biosynthetic pathway of neuromelanin. The concentrations of the 5-S-cysteinyl catechols were lower, whereas the 5-S-cysteinyl-DA/DA and 5-S-cysteinyl-DOPAC/DOPAC ratios tended to be higher in the Parkinson group compared to controls, which was interpreted as a higher degree of oxidation. High 5-S-cysteinyl-DA/DA ratios were found in the substantia nigra of a sub-population of the Parkinson group. Based on 5-S-cysteinyl-DA/DA ratios, dopamine oxidation was found to increase statistically significantly with age in the caudate nucleus, and non-significantly in the substantia nigra. In conclusion, the occurrence of 5-S-cysteinyl-DA, 5-S-cysteinyl-DOPAC and 5-S-cysteinyl-DOPA was demonstrated in dopaminergic brain areas of humans, a tendency for higher oxidation of DA in the Parkinson group compared to controls was observed as well as a statistically significant increase in DA oxidation with age. Possibly, autoxidation of DA and other catechols are involved in both normal and pathological ageing of the brain. This study confirms one earlier but small study, as well as complements one study on non-PD cases and one study on both PD cases and controls on NM bound or integrated markers or catechols.

[Sedating antihistamines - risk of severe intoxication]. / Sedativa antihistaminer ­ risk för allvarlig intoxikation.

Overdoses with the sedating antihistamines alimemazine, hydroxyzine, promethazine and propiomazine have received attention in recent years in Sweden. The Poisons Information Center has noted an increase in calls regarding intoxications, and the National Board of Forensic Medicine has concluded that these substances have directly contributed to a large number of poisoning deaths. When prescribing alimemazine, hydroxyzine, promethazine and propiomazine, their pharmacological properties, such as antihistaminergic and anticholinergic effects, and their anti-arrhythmic potential must be considered. Furthermore, it is important to also consider the risks of severe intoxication in case of overdose. The lowest possible amount should be prescribed. Special attention is required when prescribing alimemazine oral solution.

Dose-effect comparisons of the CINOD AZD3582 and naproxen on upper gastrointestinal tract mucosal injury in healthy subjects.

OBJECTIVE: The objective of this endoscopic study was to compare the effects on the gastroduodenal mucosa of healthy volunteers of different doses and dosing regimens of AZD3582, a cyclooxygenase-inhibiting nitric oxide donator (CINOD), with equimolar doses of naproxen. MATERIAL AND METHODS: Healthy volunteers were enrolled in a single-centre, randomized, double-blind, crossover trial consisting of two 12-day treatment periods and employing six sequences. The groups were: AZD3582 750 mg daily versus 375 mg twice daily (n=25), AZD3582 375 mg twice daily versus 750 mg twice daily (n=25) and naproxen 250 mg twice daily versus 500 mg twice daily (n=25). RESULTS: Gastroduodenal tract damage was similar with AZD3582 375 mg twice daily and 750 mg twice daily (mean number of erosions and ulcers+/-SD: 2.88+/-3.95 versus 3.08+/-2.80, respectively; p=0.824; 1 ulcer counted as 10 erosions). There was an indication of decreased gastroduodenal toxicity with AZD3582 750 mg daily compared with 375 mg twice daily (0.92+/-2.08 versus 2.71+/-4.75, respectively; p=0.068). Gastroduodenal toxicity was significantly lower with AZD3582 375 mg twice daily than with naproxen 250 mg twice daily (2.88+/-3.95 versus 6.16+/-9.36; p<0.05), and with AZD3582 750 mg twice daily versus naproxen 500 mg twice daily (3.08+/-2.80 versus 6.68+/-6.97; p<0.05). Equimolar twice-daily doses of AZD3582 and naproxen resulted in similar naproxen plasma levels and serum thromboxane B(2) inhibition. CONCLUSIONS: AZD3582 has an improved gastroduodenal safety profile compared with equimolar doses of naproxen. The gastroduodenal effects of AZD3582 375 mg and AZD3582 750 mg twice daily are similar. A once-daily regimen of AZD3582 might be less gastrotoxic than a twice-daily regimen.