Phenformin-associated lactic acidosis due to imported phenformin

OBJECTIVE: To emphasize the continued incidence of phenformin-associated lactic acidosis. CASE REPORT: We report a case of phenformin-associated lactic acidosis in a Chinese man who received phenformin while in China. Diagnosis was made; the patient was treated appropriately and survived. COMMENTS: Phenformin-associated lactic acidosis may still occur in the U.S.     

Observations on the efficacy and pharmacokinetics of sotalol after oral administration

The effects of sotalol after oral administration were measured on the tachycardia induced by strenuous exercise in normal subjects. Plasma sotalol levels were also determined. The oral administration of sotalol (50, 100, 200 and 400 mg) to 6 subjects produced a progressive reduction in the tachycardia induced by severe exercise. This was similar to the effects of 25, 50, 100, 200, 400 and 800 mg given to different subjects. Each increase in sotalol dose produced a successively greater reduction in exercise tachycardia. This did not appear to be maximum even with 800 mg. Oral sotalol was rapidly absorbed and produced peak blood levels in 2 - 3 hours. The plasma levels of sotalol measured 2 hours after the oral administration of 25 to 800 mg showed never more than a six-fold variation between different subject. The half-life of sotalol in plasma was 12.7 +/- SE 1.6 hours. There was a significant correlation between the logarithm of the plasma sotalol concentration and the percentage reduction of exercise heart rate. It is concluded that the oral administration of sotalol either once or twice daily (depending on dose level) will provide satisfactory 24-hour blockade of beta-adrenoceptors.     

Penetration and flow of acrylic bone cement

Fixation of prosthetic joint components into bone is influenced by the degree of mechanical interdigitation of the acrylic into cancellous interstices. The rheology of polymerizing polymethylmethacrylate was studied by pressurizing acrylic bone cement with a piston apparatus to produce flow into cylindrical cavities one to 3 mm in diameter. The acrylic penetration per unit of applied pressure increased with increasing cavity diameter. This suggests that greater penetration should occur in cancellous bone containing larger interstitial cavities. More than one-half (64 %) of the filling observed in our experiments took place within the first second of pressure application. Short duration, high level pressure pulses are the most effective means to achieve maximum penetration. Clinically, this is accomplished by vigorous finger packing. The cement should be pressurized as early as possible within the rasped cavity (immediately after dough stage if possible). The depth of penetration for 4-minute pressurization averaged three times that for 6 1/2-minute pressurization for the range of hole sizes and pressure levels tested.     

Dopaminergic activity of some apomorphine analogs

The dopaminergic activity of ten apomorphine analogs was studied in rats lesioned unilaterally with 6-hydroxydopamine in the nigro-striatal system. Of these ten compounds, N,N-dimethyl-5,6-dihydroxy-2-amino-tetralin (M-7), N-methyl-5,6-dihydroxy-2-aminotetralin (M-8) and N,N-dimethyl-4,5-dihydroxy-2-aminoindan (DDAI) exhibited potent dopaminergic stimulant activity by causing the rat to turn to the unoperated side. The turning behavior of apomorphine, M-7, DDAI and d-amphetamine were antagonized by haloperidol. M-7 and DDAI also induced pecking in pigeons and their effects were also blocked by haloperidol. It is concluded that M-7, M-8 and DDAI are direct acting central dopaminergic agents.     

Cardiovascular and neuromuscular effects of dimethyl sulfoxide in anesthetized rabbits

In rabbits anesthetized with pentobarbital, the carotid arterial blood pressure and bilateral contractions of the gastrocnemius muscles due to electrical stimulation of the sciatic nerves were recorded. Intravenous administration of up to 1 ml of dimethyl sulfoxide/kg caused profound hypotension and eventually failure of neuromuscular transmission. Caution must be used in considering dimethyl sulfoxide as a solvent for drug administration.