Medication Side Effects


Despite media misconceptions, SSRI medications are generally considered safe and not addictive. However, that’s not to say problems can’t occur, so it is important you’re aware of these and your prescribing doctor takes time to explain any potential side effects.

All medications have the potential for side effects, but that does not mean every person will suffer from them.  Most people will only experience a few mild side effects, if any at all, which can be troublesome at first, but generally improve with time, and usually subside after a week or two.

We’re often asked which is the best medication for OCD or a certain type of OCD or the one with the least side effects. Unfortunately that’s a question nobody in the world can answer because we all have different bodies and therefore all tolerate medications differently.   We could give 10 similar sized people the exact same type, brand and dosage of medication and results will vary from the negative, making them feel worse, through a range of side effects, to a positive response to the medication.

But being informed is being prepared, so it’s important you ask your prescribing doctor to discuss the potential side effects with you, of course the reality is until you start taking medications you won’t know if you will have any side effects at all, hopefully like most people you won’t.

Some people with OCD respond well to the first medication they are prescribed; others need to adjust dosages or try more than one type of SSRI, under medical supervision of course, to find the one that is most effective for them. Most of these medications do not produce immediate symptom relief; some may begin to work after a few weeks, but often it may take 12 weeks or more to notice the benefits.

Some people will notice they feel better and less tense or anxious, whilst others notice no difference at all. Interestingly, we’ve had occasions where family members on hearing that, say that to them,  their loved one seems less anxious. So sometimes medication benefits could be subtle and whilst not improving symptoms are keeping you afloat so you don’t sink further into the depths of OCD.

When are SSRI’s not for you?

Of course SSRIs aren’t suitable for everyone. They’re not usually recommended if you’re pregnant or breastfeeding because there’s a risk of side effects that may pass through breast milk to the baby.  SSRIs also need to be used with caution if you have certain underlying health problems, including bruising easily, heart problems, diabetes, epilepsy, an eye problem called glaucoma or kidney disease.  Equally if you’re having electroconvulsive treatment, SSRIs may not be suitable.  SSRIs may react unpredictably with medicines for other health conditions, including natural herbal remedies, such as St John’s wort.

So in all of these cases it’s important to discuss with your prescribing doctor, exceptions can be made if the benefits of SSRI treatment are thought to outweigh the risks.

Side effects

The good news is most people will only experience a few mild side effects when taking SSRIs. These can be troublesome at first, but they’ll generally improve with time, usually within one or two weeks. Common side effects of SSRIs include:

  • feeling agitated, shaky or anxious
  • feeling or being sick
  • mild dizziness and/or headaches
  • tired, weak and/or sleepy
  • unable to sleep
  • diarrhoea or constipation
  • dry mouth
  • unusual dreams
  • lack of concentration
  • Constant yawning
  • increase in mouth saliva
  • sweating
  • blurred vision
  • low sex drive
  • difficulty achieving orgasm during sex or masturbation
  • in men, difficulty obtaining or maintaining an erection (erectile dysfunction)

This is not a conclusive list, so should you experience any of these side effects, or others which become troublesome, it is important that you speak to your prescribing doctor or call NHS 111 if you’re in England, NHS Direct on 0845 46 47 if you’re in Wales or NHS24 which is the Scottish service, they can be called on 111.

As mentioned above, despite this seemingly comprehensive list it does not mean you will have any of those problems at all, and if you do have side effects, they may well be short lived.

It may be worth staying in touch with your prescribing doctor when you first start taking medication to discuss how well the medication is working for you. You should also make an urgent appointment to consult a doctor at any point if you experience any significant troublesome or persistent side effects listed above that last more than a few of days.

Serious side effects
The NICE Guidelines advise close and regular monitoring after starting an SSRI, and more frequently and closely in certain groups such as younger people.  Family members should be asked to keep a close eye on young people taking medication, particularly for signs of depression, thoughts about suicide or self-harm, irritability, aggressiveness, mood changes or other unusual changes in behaviour following the medication.

Dealing with Side Effects

If you experience any of the above side effects you must consult a doctor. You might be able to reduce the chance of having some of these side effects if you take SSRIs in the evening, if your doctor says you can, this means you’re asleep when the level of medicine in your body is highest.  There are also a few other tips which might help:

  • feeling sick – try taking the SSRI with or after food (perhaps nothing too rich or spicy!)
  • being unable to sleep – take the SSRI first thing in the morning if the doctor says you can
  • diarrhoea – drink plenty of water or other fluids in small, frequent sips. Don’t take any other medicines to treat diarrhoea or vomiting without speaking to a pharmacist or doctor first
  • dry mouth – try chewing sugar-free gum or sugar-free sweets
  • headaches – make sure you rest and drink plenty of fluids. Don’t drink too much alcohol
  • constipation – eat more high-fibre foods such as fresh fruit, vegetables and cereals, and drink plenty of water. Try to exercise more regularly, for example, by going for a daily walk
Coming off SSRIs

Although someone on medication may stop taking SSRIs whenever they wish, we always recommend they’re reduced gradually under supervision from their prescribing doctor.

People taking SSRIs with short Half-Life are much more likely to experience SSRI discontinuation problems.

It’s also worth pointing out what NICE recommended, that if the medication has helped a person, they should continue taking the medication for at least 12 months to ensure their symptoms continue to improve and prevent relapses.

What is a medication Half Life?!

Every medication has a certain amount of time that it remains active before the body begins to metabolise or excrete it. More simply put, the half-life of a drug is how long it takes for half of it to be eliminated from the bloodstream. This depends on how the body processes and gets rid of the drug, and can vary from a few hours to a few days for some medications. A drug’s half-life matters because a short half-life usually means more withdrawal problems compared to  a long half-life. So all SSRIs should be withdrawn slowly and under the supervision of your prescribing doctor.


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