BRINTELLIX 20 MG

Indications

• Major depressive disorder
• Anxiety disorders

Dosage

Children: Refer to the BNF for Children for specific dosing information

Adults: Initially 10 mg once daily; adjusted according to response to 5–20 mg once daily.

Mechanism of action

Vortioxetine acts as a serotonin modulator and simulator (SMS) with a complex mechanism of action. It inhibits the serotonin transporter, thus increasing serotonin levels in the synaptic cleft. Additionally, it acts as a partial agonist at the 5-HT1B receptor, an agonist at the 5-HT1A receptor, and an antagonist at the 5-HT3, 5-HT1D, and 5-HT7 receptors, contributing to its antidepressant and anxiolytic effects.

Pharmacodynamics

Vortioxetine exhibits high affinity for the human serotonin transporter (Ki=1.6 nM) and selectively inhibits serotonin reuptake (IC50=5.4 nM). Its action on serotonin receptors includes antagonism of 5-HT3 (Ki=3.7 nM), 5-HT1D (Ki=54 nM), and 5-HT7 (Ki=19 nM) receptors, while showing partial agonism at 5-HT1B (Ki=33 nM) and full agonism at 5-HT1A (Ki=15 nM). These interactions enhance serotonergic neurotransmission, which is crucial for mood regulation.

Pharmacokinetics

Vortioxetine is administered orally and is characterized by good oral bioavailability. It undergoes extensive hepatic metabolism, primarily via CYP2D6, leading to various metabolites. The elimination half-life is approximately 66 hours, allowing for once-daily dosing. The drug's pharmacokinetic profile may be affected by other medications that induce or inhibit CYP2D6.

Mechanism of action

Vortioxetine is classified as a serotonin modulator and simulator (SMS) as it has a multimodal mechanism of action towards the serotonin neurotransmitter system whereby it simultaneously modulates one or more serotonin receptors and inhibits the reuptake of serotonin. More specifically, vortioxetine acts via the following biological mechanisms: as a serotonin reuptake inhibitor (SRI) through inhibition of the serotonin transporter, while also acting as a partial agonist of the 5-HT1B receptor, an agonist of 5-HT1A, and antagonist of the 5-HT3, 5-HT1D, and 5-HT7 receptors. 1-(2-(2,4-Dimethylphenyl-sulfanyl)-phenyl)-piperazine (Lu AA21004) is a human (h) serotonin (5-HT)(3A) receptor antagonist (K(i) = 3.7 nM), h5-HT(7) receptor antagonist (K(i) = 19 nM), h5-HT(1B) receptor partial agonist (K(i) = 33 nM), h5-HT(1A) receptor agonist (K(i) = 15 nM), and a human 5-HT transporter (SERT) inhibitor (K(i) = 1.6 nM) (J Med Chem 54:3206-3221, 2011). Here, we confirm that Lu AA21004 is a partial h5-HT(1B) receptor agonist [EC(50) = 460 nM, intrinsic activity = 22%] using a whole-cell cAMP-based assay and demonstrate that Lu AA21004 is a rat (r) 5-HT(7) receptor antagonist (K(i) = 200 nM and IC(50) = 2080 nM). In vivo, Lu AA21004 occupies the r5-HT(1B) receptor and rSERT (ED(50) = 3.2 and 0.4 mg/kg, respectively) after subcutaneous administration and is a 5-HT(3) receptor antagonist in the Bezold-Jarisch reflex assay (ED(50) = 0.11 mg/kg s.c.). In rat microdialysis experiments, Lu AA21004 (2.5-10.0 mg/kg s.c.) increased extracellular 5-HT, dopamine, and noradrenaline in the medial prefrontal cortex and ventral hippocampus. Lu AA21004 (5 mg/kg per day for 3 days; minipump subcutaneously), corresponding to 41% rSERT occupancy, significantly increased extracellular 5-HT in the ventral hippocampus. Furthermore, the 5-HT(3) receptor antagonist, ondansetron, potentiated the increase in extracellular levels of 5-HT induced by citalopram. Lu AA21004 has antidepressant- and anxiolytic-like effects in the rat forced swim (Flinders Sensitive Line) and social interaction and conditioned fear tests (minimal effective doses: 7.8, 2.0, and 3.9 mg/kg). In conclusion, Lu AA21004 mediates its pharmacological effects via two pharmacological modalities: SERT inhibition and 5-HT receptor modulation. In vivo, this results in enhanced release of several neurotransmitters and antidepressant- and anxiolytic-like profiles at doses for which targets in addition to the SERT are occupied. The multimodal activity profile of Lu AA21004 is distinct from that of current antidepressants. The mechanism of the antidepressant effect of vortioxetine is not fully understood, but is thought to be related to its enhancement of serotonergic activity in the CNS through inhibition of the reuptake of serotonin (5-HT). It also has several other activities including 5-HT3 receptor antagonism and 5-HT1A receptor agonism. The contribution of these activities to vortioxetine's antidepressant effect has not been established. The monoaminergic network, including serotonin (5-HT), norepinephrine (NE), and dopamine (DA) pathways, is highly interconnected and has a well-established role in mood disorders. Preclinical research suggests that 5-HT receptor subtypes, including 5-HT1A, 5-HT1B, 5-HT3, and 5-HT7 receptors as well as the 5-HT transporter (SERT), may have important roles in treating depression. This study evaluated the neuropharmacological profile of Lu AA21004, a novel multimodal antidepressant combining 5-HT3 and 5-HT7 receptor antagonism, 5-HT1B receptor partial agonism, 5-HT1A receptor agonism, and SERT inhibition in recombinant cell lines. Extracellular 5-HT, NE and DA levels were evaluated in the ventral hippocampus (vHC), medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) after acute and subchronic treatment with Lu AA21004 or escitalopram. The acute effects of LuAA21004 on NE and DA neuronal firing were also evaluated in the locus coeruleus (LC) and ventral tegmental a

Pharmacodynamics

Vortioxetine binds with high affinity to the human serotonin transporter (Ki=1.6 nM), but not to the norepinephrine (Ki=113 nM) or dopamine (Ki>1000 nM) transporters. Vortioxetine potently and selectively inhibits reuptake of serotonin by inhibition of the serotonin transporter (IC50=5.4 nM). Specifically, vortioxetine binds to 5­HT3 (Ki=3.7 nM), 5­HT1A (Ki=15 nM), 5­HT7 (Ki=19 nM), 5­HT1D (Ki=54 nM), and 5­HT1B (Ki=33 nM), receptors and is a 5­HT3, 5­HT1D, and 5­HT7 receptor antagonist, 5­HT1B receptor partial agonist, and 5­HT1A receptor agonist.