SNRIAntidepressiva

SNRIAntidepressiva, or serotonin-norepinephrine reuptake inhibitors (SNRIs), are a class of antidepressant medications that increase the levels of serotonin and norepinephrine in the brain by inhibiting their reuptake into presynaptic neurons. They are used to treat major depressive disorder and a range of anxiety disorders, as well as certain chronic pain conditions.

Mechanism and characteristics: SNRIs block the transporters for serotonin (SERT) and norepinephrine (NET) with varying affinity, leading to enhanced monoaminergic signaling. The noradrenergic effects can help with fatigue and pain but may raise blood pressure and heart rate at higher doses. Clinical effects typically emerge after several weeks of treatment.

Common agents: venlafaxine, duloxetine, desvenlafaxine, and levomilnacipran are frequently prescribed SNRI medications. Dosing and tolerability vary by agent and indication.

Indications and uses: beyond major depressive disorder, SNRIs are used for generalized anxiety disorder, social anxiety disorder, panic disorder, and some chronic pain conditions such as fibromyalgia and diabetic neuropathy. They may be chosen when depression coexists with anxiety or pain symptoms.

Adverse effects and safety: possible side effects include nausea, dry mouth, insomnia or sedation, dizziness, constipation, sweating, and sexual dysfunction. Blood pressure and heart rate can be affected. Discontinuation symptoms may occur if the medication is stopped abruptly. There is a risk of serotonin syndrome when combined with other serotonergic drugs or MAO inhibitors. Caution is advised in bipolar disorder due to mania risk.

Pregnancy and interactions: use in pregnancy should be limited to clear indications; interactions with other serotonergic drugs and anticoagulants/antiplatelets should be considered.