Nantradol hydrochloride: pharmacokinetics and behavioral effects after acute and chronic treatment.

Studies with [3H]nantradol hydrochloride indicate that nantradol is extensively metabolized after oral administration. By using a liquid chromatography assay with electrochemical detection, specific for both nantradol and desacetylnantradol, only desacetylnantradol is detected in plasma of rats and dogs dosed with nantradol. In animal analgetic tests, desacetylnantradol exhibits activity at least equal to nantradol.

Six month inhalation studies of pirbuterol acetate aerosol in the beagle dog and squirrel monkey.

Groups of Beagle dogs and Squirrel monkeys were exposed to aerosols of pirbuterol acetate, a new bronchodilator at doses of 0, 200, 400 and 800 micrograms of pirbuterol/kg body weight daily for 6 months. Each group consisted of 4 dogs or 6 monkeys per sex. Dogs were exposed by face mask and monkeys were exposed by head only in a manifold.

Comparative pharmacology and clinical efficacy of newer agents in treatment of heart failure.

The animal and human pharmacology of several new drugs (prazosin, trimazosin, pirbuterol, and carbazeran) useful in the treatment of congestive heart failure (CHF) is delineated in relation to the pharmacology of other agents employed for CHF management. Prazosin and trimazosin are selective alpha 1-blockers that cause a balanced increase in cardiac output (CO) and reduction in left ventricular filling pressure (LVFP); the reduction in diastolic blood pressure with these drugs is significantly related to increase in treadmill exercise, fall in LVFP, and increase in CO. Pirbuterol is a relatively selective beta 2-agonist with somewhat greater effects on CO than on LVFP.

Pharmacokinetics and cardiopulmonary effects in dogs of sublingual pirbuterol, a new bronchodilator.

The time course of plasma concentrations of sublingually administered pirbuterol was investigated in anesthetized dogs; there was a dose-related increase in plasma drug concentrations which reached maximum values 1 hr or more after administration. In a second study plasma drug levels were correlated with antagonism of histamine-induced changes in pulmonary compliance and resistance which also reached maximum values 1 hr or more after drug administration, although marked antagonism was apparent at 15 to 30 min; blood pressure was unaltered at any dose level and heart rate was influenced only at the highest dose level. A convenient method for study of the bioavailability of sublingual formulations is described, and the potential usefulness of a sublingual dosage form of pirbuterol is discussed.