Norepinephrine's Role in Treating Mood Problems

Norepinephrine, also known as noradrenaline, is a hormone and neurotransmitter that participates in various functions, including mood regulation and energy mobilization. Its involvement in these processes has led to the development of medications that target norepinephrine activity to treat mood disorders.

Overview Serotonin-norepinephrine reuptake inhibitors (SNRIs) are medications that impede the reuptake of norepinephrine and serotonin, increasing their availability in the brain. By enhancing these neurotransmitters' levels, SNRIs aim to improve mood, offset anxiety, and address other conditions.

SNRIs' Application in Mood Disorders SNRIs are employed in the treatment of major depression, bipolar disorder aspects, anxiety disorders, chronic pain, and fibromyalgia. Cymbalta (duloxetine), Effexor (venlafaxine), Fetzima (levomilnacipran), and Pristiq (desvenlafaxine) are among the SNRIs approved for major depression. While no SNRIs have specific FDA approval for bipolar disorder, they may be incorporated into individual treatment plans.

Side Effects Associated with SNRIs SNRIs can elevate blood pressure, particularly at higher doses, necessitating regular blood pressure monitoring. Common side effects include anxiety, constipation, difficulty urinating, dizziness, dry mouth, fatigue, drowsiness, headache, loss of appetite, nausea, vomiting, sexual complications, and excessive sweating.

Variation in SNRIs Each SNRI exhibits unique chemical characteristics and FDA approvals:

• Effexor (Venlafaxine) (1993): Approved for depression, panic disorder, social phobia, and generalized anxiety disorder (GAD); its influence on serotonin reabsorption surpasses that on norepinephrine.

• Cymbalta (Duloxetine) (2004): Approved for diabetic peripheral neuropathy, depression, GAD, fibromyalgia, osteoarthritis, and nerve pain; it inhibits serotonin reabsorption more than norepinephrine, but less than Effexor.

• Pristiq and Khedezla (Desvenlafaxine): Approved for major depression; its mode of action is similar to Cymbalta.

• Savella (Milnacipran): Approved for fibromyalgia; it hinders serotonin and norepinephrine reabsorption equally, with a potential bias towards norepinephrine.

• Fetzima (Levomilnacipran) (2013): Approved for depression; its impact on norepinephrine reabsorption doubles that on serotonin reabsorption.