Pharmacodynamics +<unk>  Site Ki (nM) Species Ref 5-HT1A 15–81 Human 5-HT1B 4,10034–151 HumanRodent 5-HT1D 4,900 Human 5-HT1E >10,000 Human 5-HT1F >10,000 Human 5-HT2A 9,333 Human 5-HT2B 2,188 Human 5-HT2C >10,000 Human 5-HT3 ≥6,610 Multiple 5-HT5B >1,000 Rat 5-HT6 >10,000 () Mouse 5-HT7 >10,000 Human α1 7,585 Pigeon α2 β1 0.52–2.6 Human β2 0.40–4.8 Human β3 44 Human D2-like >10,000 Rat D2 >10,000 Pigeon D3 >10,000 Pigeon Values are Ki (nM), unless otherwise noted. The smaller the value, the more strongly the drug binds to the site.<unk>  is a first generation, non-selective beta blocker in the class of β-adrenergic receptor antagonists. On the receptor level it is a competitive partial agonist. It possesses intrinsic sympathomimetic activity, meaning it has some degree of agonist effects in the absence of competing ligands.<unk>  shows membrane-stabilizing effects like quinidine, possibly accounting for its antiarrhythmic effects. It also acts as a serotonin 5-HT1A receptor partial agonist (intrinsic activity = 20–25%) or functional antagonist. Pharmacokinetics<unk>  is rapidly and well absorbed from the GI tract. It undergoes some first-pass-metabolization leading to an oral bioavailability of 50-95%. Patients with uremia may have a reduced bioavailability. Food does not alter the bioavailability, but may increase the resorption. Following an oral single dose of 20 mg peak plasma concentrations are reached within 1–2 hours. The effect of<unk>  on pulse rate (lowering) is evident after 3 hours. Despite the rather short halflife of 3–4 hours, hemodynamic effects persist for 24 hours after administration. Plasma halflives are increased to 3-11.5 hours in patients with renal impairment, to 7–15 hours in elderly patients, and from 2.5–30 hours in patients with liver cirrhosis. Approximately 2/3 of<unk>  is metabolized in the liver giving hydroxylates, which are found in the urine as gluconurides and ethereal sulfates. The remaining 1/3 of<unk>  is excreted in urine in unchanged form.
Pindolol
Nadolol
Betaxolol
Isoprenaline
Oxprenolol
Atenolol
Esmolol
Carteolol