Download SSRIs and SNRI

SSRIs and SNRIs
Selective serotonin reuptake inhibitors (SSRIs) or serotonin and noradrenaline reuptake
inhibitors (SNRIs) may be added to current PoTS medications, when others such as
fludrocortisone and midodrine have not achieved the desired symptom control.
Examples of those used in PoTS
SSRIs – paroxetine, citalopram, escitalopram, sertraline
SNRIs –bupropion, venlafaxine, duloxetine
What are SSRIs and SNRIs commonly used for?
SSRIs and SNRIs are primarily use in the management of depression and anxiety.
Other common uses include:
Bupropion (Zyban) – smoking cessation
Duloxetine – stress incontinence, diabetic nerve problems
Why should I take an SSRI/SNRI when I am neither depressed nor anxious?
Serotonin is a natural chemical made by our body, which has many roles, including the
autonomic regulation of heart rate, blood pressure and gut motility.
It is thought that the production and regulation of serotonin is faulty in people with autonomic
dysfunction such as PoTS which would explain why these medications may help, though the
evidence for their benefit in PoTS remains unproven.
They have been used in the management of vasovagal syncope and orthostatic hypotension
(low BP when standing), although exactly how they work remains uncertain.
SSRIs may also improve symptoms of irritable bowel syndrome which is common in PoTS.
*Some patients have found the quality of sleep to be improved while taking an SSRI,
resulting in decreased day time tiredness.
SNRIs stop the reuptake of both serotonin and noradrenaline (which are required for the
autonomic nervous system to function).
Which one should I try?
Even though SSRIs are similar to each other, if you do not respond to or tolerate one, you
may have better success with another.
Sertraline, citalopram and escitalopram tend to be better tolerated than other SSRIs such as
paroxetine which also carries the highest risk of developing withdrawal side effects.
SNRIs may worsen tachycardia in patient with PoTS due to the increase in circulating
noradrenaline.
SNRIs which have been used include bupropion, venlafaxine and duloxetine.
What are the side effects of SSRIs/SNRIs?
Some of the common side effects you may experience include:
 Difficulty in sleeping, abnormal dreams, tiredness
 Nausea, vomiting, diarrhoea, constipation, stomach pains
 Increase or decreased appetite, weight gain or loss
 Anxiety and nervousness, agitation, shaking
 Decreased sexual interest and sexual dysfunction
 Dry mouth
 Muscle and joint pain
 Tingling or numbness in the hands or feet
 Ringing in the ears (tinnitus)
 Itchy rash
 Vision problems
See specific drug information leaflet for a more details of potential side effects.
Serotonin syndrome
Serotonin syndrome is a response to elevated amounts of serotonin in the body when taking
medication that alters body serotonin levels. This primarily occurs when there is an
interaction with other medication or overdose, causing an increase in serotonin available.
Occasionally, it can occur by taking a normal prescribed dose of an SSRI alone.
Symptoms may include – Tachycardia (fast heart rate), confusion, agitation, muscle
twitching or spasms, excessive sweating, shivering, tremor, diarrhoea, lack of coordination,
restlessness, fever.
If you are concerned that you are developing serotonin syndrome, seek immediate medical
advice.
Who should not take them?
SSRIs should be used with caution in patients with epilepsy, cardiac disease, diabetes
mellitus, susceptibility to angle-closure glaucoma, bleeding into the gut.
SSRIs may also impair performance of skilled tasks (e.g. driving).
Can I take SSRIs/SNRIs with my other medication?
SSRI/SNRIs do interact with a number of prescribed and interactions will vary depending on
the type of SSRI/SNRI you are prescribed – speak with your own GP, specialist or
community pharmacist.
SSRIs can also interact with over the counter medication such as non-steroidal antiinflammatory drugs (NSAID) eg ibuprofen and aspirin increasing the risk of bleeding into the
stomach if taken at the same time.
Drinking alcohol while taking an SSRI may increase drowsiness.
Is safe to take in pregnancy?
The risks of taking SSRIs/SNRIs during pregnancy and while breast feeding, remain
unknown therefore manufactures do not recommend their use.
If the benefits outweigh the risks, SSRIs may be used with extreme caution, and only after
advice from your specialist.
Withdrawal
Abruptly stopping or reducing a dose of an SSRI can cause withdrawal side effects, the
symptoms of which may include nervousness, anxiety, irritability, dizziness, sleep problems,
difficulty concentrating, headache, nausea and vomiting.
Tapering a dose over a few weeks will reduce the risk of withdrawal side effects. This should
be carried out with guidance from your GP or specialist.
*Currently no available medical evidence but generally accepted by experts
Details regarding the sources of evidence used in the production of this leaflet are available on the PoTS UK website.
http://www.potsuk.org/sources_of_evidence
Written by: Lorna Busmer
Medically approved by: Dr Satish Raj, Dr Lesley Kavi
Updated: 24/9/13
Review Date: 24/9/15
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