Hyperhomocyst(e)inaemia, but not MTHFR C677T mutation, as a risk factor for non-arteritic ischaemic optic neuropathy.

BACKGROUND/AIMS: Hyperhomocyst(e)inaemia has been identified as a strong risk factor for stroke, myocardial infarction, and deep vein thrombosis. A point mutation of methylene tetrahydrofolate reductase (MTHFR C677T) has been associated with increased plasma homocyst(e)ine levels. To investigate whether hyperhomocyst(e)inaemia and/or MTHFR C677T mutation are associated with non-arteritic ischaemic optic neuropathy (NAION), a case-control study including 59 consecutive patients with NAION and 59 controls matched for age and sex was performed. METHODS: Fasting plasma homocyst(e)ine levels, MTHFR C677T genotypes, and plasma levels of folate and vitamin B-12 were determined. RESULTS: Mean plasma homocyst(e)ine levels were significantly higher in patients than in controls (11.8 (SD 5.7) micromol/l v 9.8 (2.5) micromol/l, p = 0.02). The odds ratio for patients with homocyst(e)ine levels exceeding the 95th percentile of control homocyst(e)ine levels was 5.8 (95% CI 1.5-21.4). Mean plasma folate levels were significantly lower in patients than in controls (4.3 (1.7) ng/ml v 5.5 (1.9) ng/ml, p = 0.001), whereas plasma vitamin B-12 levels did not differ significantly. Prevalence of the MTHFR C677T mutation was not significantly increased in patients with NAION compared with controls. CONCLUSION: These results suggest that hyperhomocyst(e)inaemia, but not MTHFR C677T mutation is associated with NAION. Determination of plasma homocyst(e)ine levels might be of diagnostic value in patients with NAION.

[Bioavailability of morphine after oral administration as retard tablets]. / Die Bioverfügbarkeit von Morphin nach oraler Verabreichung als Retard-Filmtabletten.

The oral bioavailability of morphine following administration of a single dose of 30 mg morphine hydrochloride as Vendal retard film tablets (Lannacher Heilmittel) was investigated and compared with the bioavailability of morphine following administration of 30 mg morphine sulphate as Mundidol retard film tablets (Mundipharma). A randomized crossover study was conducted in 24 male, healthy volunteers. In 6 of them a pilot study with formulations containing 60 mg was conducted. Morphine and its metabolites were quantitated with an immunofluorimetric solid-phase assay (DELFIA). With regard to the following parameters the novel controlled-release formulation was statistically different from the reference formulation: area under the concentration-time curve, time to maximum and half value duration. After a single dose of the test formulation analgesic serum levels were maintained over a longer lasting period of time than after administration of the reference formulation. The maximal levels in serum and the elimination half life were not different. From the improved pharmacokinetic parameters of the novel controlled-release formulation an improved clinical efficacy can be expected.