Pharmacological studies with slow-release formulations of oxprenolol in man

Absorption and excretion of rapid and slow release oxprenolol and their effects on heart rate and blood pressure during exercise.

“…This is in contrast with the studies of Davidson et al (1976) where significant differences were found at 4, 8 and 12 h between the effects of oxprenolol 80 mg and oxprenolol SR 80 mg on exercise heart rate. Davidson et al (1976) found that maximum inhibition of the heart rate response to a single load of exercise occurred at plasma oxprenolol concentrations of about 100 ng/ml.…”

“…disintegration apparatus by immersion in simulated gastric juice (pH 1.3) and in simulated intestinal fluid (pH 7.5) as described by Davidson et al (1976).…”

“…This may have potential value by improving compliance of patients if it resulted in dosage with fewer tablets daily than is required with the standard preparation. Although some studies have suggested that the effect of 80 mg oxprenolol in slow release form is more prolonged than the standard 80mg tablets (Davidson, Thadani, Taylor, Hess & Reiss, 1976;West, Kendall, Mitchard & Faragher, 1976), no previous study has compared the same doses of the commercially available 160 mg slow release preparation (SR) with regular oxprenolol (RR).…”

Can once daily dosage be effective in the treatment of hypertension throughout 24 hours? A controlled evaluation of sustained release oxprenolol [letter]

“…The progressive increase in post-exercise pulse rate during the 24 h between treatments with sustained release oxprenolol is in agreement with the observations on the same drug in healthy volunteers (West, Kendall & Mitchard, 1976;Davidson, Thadani, Taylor, Riess & Hess, 1976) and on single doses of metoprolol in hypertensive patients (Reybrouck, Amery, Fagard, Jousten, Lijnen & Meulepas, 1978).The changes in plasma oxprenolol concentrations appear to account for this variation in postexercise pulse rate and, since there is no accumulation of the drug, the concentrations found at 24 h after dosing would be expected to be associated with little or no effect in exercise heart rate. Nevertheless, although the study showed this rise in pulse rate over 24h to be significant, no significant rise in blood pressure was observed.…”

Speed of onset of pharmacodynamic activity of propranolol, practolol, oxprenolol and metoprolol after intravenous infection in man.

“…Moreover, the reduction in isoprenaline tachycardia correlates well with the plasma concentration of the drug, both in the case of propranolol (McDevitt & Shand, 1975) and oxprenolol (Davidson et al, 1976). The former authors studied the rapidity of suppression of isoprenaline tachycardia and although they used a much smaller test dose of propranolol (0.1 mg compared with our dose of 8 mg) at a lower and less sensitive range of tachycardia than in our studies, their findings were very similar.…”