Ergoline class Pharmacokinetics of Bromocriptine The absorption of the oral dose is approximately 28% however, only 6% reaches the systemic circulation unchanged, due to a substantial first-pass effect. Bromocriptine reaches mean peak plasma levels in about 1–1.5 hours after a single oral dose. The drug has high protein binding, ranging from 90-96% bound to serum albumin. Bromocriptine is metabolized by CYP3A4 and excreted primarily in the feces via biliary secretion. Metabolites and parent drugs are mostly excreted via the liver, but also 6% via the kidney. It has a half-life of 2–8 hours. Pharmacokinetics of Pergolide Pergolide has a long half-life of about 27 hours and reaches a mean peak plasma level in about 2–3 hours after a single oral dose. The protein binding is 90% and the drug is mainly metabolized in the liver by CYP3A4 and CYP2D6. The major route of excretion is through the kidneys. Drug Maintenance Half-life Protein binding Peak plasma Metabolism Excretion Bromocriptine Oral, 2.5–40 mg/day 2–8 hours 90-96% 1-1,5 hours Hepatic, via CYP3A4, 93% first-pass metabolism Bile, 94-98% Renal, 2-6% Pergolide Oral, 0.05 mg/day Usual response up to 0.1 mg per<unk> y 27 hours 90% 2–3 hours Extensively hepatic Renal, 50% Fecal 50% Non-Ergoline class Pharmacokinetics of Pramipexole Pramipexole reaches maximum plasma concentration 1–3 hours post-dose. It is about 15% bound to plasma proteins and the metabolism is minimal. Pramipexole has a long half-life, around 27 hours. The drug is mostly excreted in the urine, around 90%, but also in feces. Pharmacokinetics of Ropinirole Ropinirole is rapidly absorbed after a single oral dose, reaching plasma concentration in approximately 1–2 hours. The half-life is around 5–6 hours. Ropinirole is heavily metabolized by the liver and in vitro studies show that the enzyme involved in the metabolism of ropinirole is CYP1A2. Pharmacokinetics of Rotigotine Since rotigotine is a transdermal patch it provides continuous drug delivery over 24 hours. It has a half-life of 3 hours and the protein binding is around 92% in vitro and 89.5% in vivo. Rotigotine is extensively and rapidly metabolized in the liver and by the CYP enzymes. The drug is mostly excreted in urine (71%), but also in feces (23%). Drug Maintenance Half-life Protein binding Peak plasma Metabolism Excretion Pramipexole Oral, 0.125 mg 3x/day (IR) Oral, 0.375 mg/day (ER) 8–12 hours 15% 1–3 hours Minimal 5–6 hours 10-40% 1–2 hours Hepatic, via P450 CYP1A2 — can increase ↑ INR Renal > 88% Rotigotine Transdermal, 2 – 4 mg/day 3 hours 92% 24 hours Hepatic (CYP-mediated). Urine 71% Fecal 23%
Dopamine agonist
Dopamine antagonist
Alpha-adrenergic agonist
Norepinephrine–dopamine disinhibitor
Muscarinic antagonist
Beta-adrenergic agonist
Serotonin receptor agonist
Orexin antagonist