Normal values for ambulatory blood pressure are presented in a randomly selected age- and gender-stratified population. Differences between office blood pressure and ambulatory blood pressure increased with age suggesting that the previously observed higher blood pressure seen in the elderly partly might be explained by a greater impact of white coat hypertension in older people.

A number of randomised studies indicate that a single high dose of aminoglycoside every 24 h may be more efficient and less toxic than the same dose divided into multiple daily doses. In the meta-analysis of 16 studies described here, which included more than 1200 patients, the relative chance (i.e. the relative risk, RR) of cure of the single-dose regime compared with the multiple-dose regime was 1.027, indicating that the single daily dose regime had a 2.7% higher cure rate (NS). The RR of avoiding nephrotoxicity was 1.001 (NS) and the RR of avoiding ototoxicity was 1.001 (NS). It is concluded that there is no difference concerning efficacy and safety between single-dose and multiple-dose regimes for administration of aminoglycosides.

Organic antithyroid drugs used today include propylthiouracil and the mercaptoimidazolines, carbimazole and methimazole. They can be measured with accuracy and in small quantities in serum by gas-liquid chromatography, high performance liquid chromatography and radio-immunoassay. Bioavailability of these drugs varies from 80 to 95%. During absorption carbimazole, which itself is inactive, is completely converted to methimazole. The total volume of distribution is about 40L for methimazole and around 30L for propylthiouracil, which is about 80% protein-bound, while methimazole is virtually non-protein-bound. Drug transfer across the placenta and into breast milk is also higher for the more lipid-soluble methimazole than for propylthiouracil, which is excreted into breast milk only in small quantities so that no harmful effect to the suckling infant is to be expected. Both drugs are concentrated in the thyroid gland, exerting an effect on intrathyroidal iodine metabolism for periods exceeding those in which serum concentrations can be measured. Less than 10% of both drugs is excreted unchanged in the urine, but detailed metabolic pathways are unknown. The half-life of methimazole is 3 to 5 hours with a total clearance of about 200ml/minute. Propylthiouracil has a half-life of 1 to 2 hours with a clearance of around 120ml/min/m2. Some studies have shown an increased rate of metabolism of anti-thyroid drugs in hyperthyroidism, in particular for methimazole. No reliable information exists regarding pharmacokinetics of these agents in renal and hepatic failure or in children. The clearance of propylthiouracil is unchanged in the elderly. Several mechanisms for the inhibiting effect of these agents on intrathyroidal hormone metabolism have been suggested. In contrast to methimazole, propylthiouracil inhibits the peripheral conversion of thyroxine to triiodothyronine. Preliminary dose-response studies with propylthiouracil suggest a peak therapeutic serum concentration of above 4 micrograms/ml in the treatment of thyrotoxicosis. The choice between the antithyroid drugs is based more upon personal preference and experience than on strict pharmacological principles, as no important differences exist between these drugs with regard to the rate of remission or frequency of occurrence of serious adverse reactions.