SNRI

SNRIs slow the reabsorption of both serotoninSerotoninA chemical messenger involved in mood, sleep, appetite, digestion and much more. About 90% of the body's serotonin is in the gut. It is not simply a "happy chemical".Read the full definition and noradrenaline (called norepinephrine in the US). They are used for depressionDepressionA medical condition in which low mood or loss of interest lasts most of the day, nearly every day, for at least two weeks, and affects sleep, energy and daily life.Read the full definition and generalised anxiety disorderGeneralised anxiety disorderA long-term condition in which you worry about many different things, most days, for months, and find the worry very hard to control.Read the full definition, often when an SSRISSRISelective serotonin reuptake inhibitor: the most commonly prescribed type of antidepressant, used for depression and many anxiety conditions. Examples are sertraline, fluoxetine, escitalopram, citalopram and paroxetine.Read the full definition has not helped enough. Duloxetine is also used for some kinds of long-term pain, including nerve pain.

Points to know

• Like other antidepressants, they take a few weeks to work
• Common side effects include nausea, dry mouth, sweating, headache and dizziness
• They can raise blood pressureBlood pressureBlood pressure is the force of blood against the artery walls, written as two numbers in millimetres of mercury: the higher one is the pressure as the heart squeezes, the lower one the pressure as it refills. It varies through the day, so a diagnosis is never made on one reading.Read the full definition, so have it checked, especially if you have hypertensionHypertensionHypertension is blood pressure that stays high enough, over repeated proper measurements, to damage the arteries over time. It almost never causes symptoms, which is why it is found by measuring rather than by feeling unwell.Read the full definition
• Stopping too quickly can cause discontinuation symptomsAntidepressant discontinuation syndromeUnpleasant symptoms — dizziness, "brain zaps", flu-like feelings, anxiety, poor sleep — that can follow stopping or cutting down an antidepressant too quickly. Reducing gradually with a doctor lowers the risk.Read the full definition, often marked with venlafaxine — reduce only with your doctor