Other common first line drug options include SNRI’s (serotonin and norepinephrine reuptake inhibitors) like venlafaxine.

Serotonin and noradrenaline (also called norepinephrine) are neurotransmitters made by the cells in the brain. Neurotransmitters are chemicals used by brain cells to connect and communicate with each other. SNRI antidepressants slow the rate that the brain breaks down serotonin and noradrenaline. This leads to an increase in serotonin and noradrenaline activity in the brain. (Mirtazapine has a similar effect by a slightly different mechanism.) This has been shown to improve symptoms of depression and anxiety. It also reduces obsessions and compulsions in obsessive-compulsive disorders (OCD).

Common side effects include:

Somnolence (Mirtazapine, Remeron/Avanza)

Intensified dreaming

Mild nausea and headache which usually clear after a few days of use

Diarrhoea and abdominal cramping pain

Agitation and physical restlessness

Reduced sex drive and difficulty reaching a orgasm

The effect on weight is unclear, however appetite reduction and weight loss most likely with Venlafaxine (Efexor) and Nefazadone (Serzone)

Weight gain most likely with Mirtazapine (Remeron/Avanza)

The effect on sleep is unpredictable, however broken sleep is common with some of the SNRI medications (Venlafaxine, Efexor)

Other SNRIs may cause sleepiness (Mirtazapine, Remeron/Avanza)