Comparative Pharmacology
Head-to-head clinical analysis: FENFLURAMINE versus PLEGINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FENFLURAMINE versus PLEGINE.
FENFLURAMINE vs PLEGINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fenfluramine is a serotonin-releasing agent and serotonin receptor agonist. It increases extracellular serotonin levels by promoting release from presynaptic neurons and inhibiting reuptake, leading to appetite suppression. Its antiseizure effect in Dravet syndrome is thought to be mediated via 5-HT2 receptor activation, enhancing inhibitory neurotransmission.
Plegine (phendimetrazine) is a sympathomimetic amine that acts as an anorectic agent. It stimulates the hypothalamus to release norepinephrine and dopamine, thereby suppressing appetite. The exact mechanism is thought to involve the release of catecholamines from presynaptic nerve terminals in the lateral hypothalamic feeding center, leading to decreased food intake.
25 mg orally three times daily, titrated to a maximum of 400 mg daily in divided doses.
25-50 mg orally once daily at bedtime, maximum 100 mg/day.
None Documented
None Documented
Clinical Note
moderateDexfenfluramine + Deferasirox
"The serum concentration of Deferasirox can be increased when it is combined with Dexfenfluramine."
Clinical Note
moderateDexfenfluramine + Haloperidol
"The metabolism of Haloperidol can be decreased when combined with Dexfenfluramine."
Clinical Note
moderateDexfenfluramine + Tenofovir disoproxil
"The metabolism of Tenofovir disoproxil can be decreased when combined with Dexfenfluramine."
Clinical Note
moderateDexfenfluramine + Artesunate
Terminal elimination half-life of fenfluramine is approximately 20 hours (range 13–30 hours) for the parent drug, while its active metabolite norfenfluramine has a longer half-life of approximately 30–34 hours. This extended half-life supports twice-daily dosing but contributes to accumulation with repeated administration.
Terminal elimination half-life: 4–8 hours (mean 6 hours). Clinical context: Steady-state achieved after 24–48 hours of repeated dosing.
Renal excretion of unchanged drug accounts for <1% of the administered dose; fenfluramine is extensively metabolized, with metabolites primarily excreted renally. Approximately 60–70% of the dose appears in urine as metabolites (including norfenfluramine and other dealkylated products) within 72 hours, and about 5–10% is eliminated in feces via biliary excretion.
Renal: 40% unchanged; Hepatic metabolism: 60% (biliary/fecal elimination of metabolites).
Category C
Category C
Anorexiant
Anorexiant
"The serum concentration of the active metabolites of Artesunate can be reduced when Artesunate is used in combination with Dexfenfluramine resulting in a loss in efficacy."