Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1   Pharmacodynamic properties

Mechanism of action
Razin is a sympathomimetic amine with significant anorectic activity in animal models. Its appetite suppressant effect is generally considered to be exerted through the hypothalamus, but it is not certain that this is the only effect related to weight loss. Phentermine has major effects on the dopaminergic and noradrenergic nervous systems. The cardiovascular effects include a pressor response and increase in heart rate and force of contraction.
Clinical trials
No data available

Pharmacokinetic Properties

5.2   Pharmacokinetic properties

Absorption
Absorption of phentermine is almost complete. The rate of absorption from the resin complex is significantly slower than that from the hydrochloride salt, resulting in a lower and later peak blood level. Phentermine is readily absorbed from the gastrointestinal tract.
Metabolism & Excretion
Following an oral dose of phentermine capsule, one study demonstrated urinary excretion of unchanged drug ranging from 62.7% to 84.8% in 72 hours. The remainder is metabolised by the liver. The half-life of phentermine is about 25 hours. In one study in volunteers acidification of the urine reduced the half-life to 7 to 8 hours