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Dr. K
Dr. K, Psychiatrist
Category: Mental Health
Satisfied Customers: 358
Experience:  15 years clinical experience in all areas of psychiatry. Holistic and practical approach.
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I have recently been prescribed Agomelatine (Valdoxan) 25mg.

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I have recently been prescribed Agomelatine (Valdoxan) 25mg. I understand that I have to have a liver function test done at 6, 12 and 24 weeks and would like to know why this is necessary please.

I also understand that a side effect of this medication is insomnia. This concerns me too, as I have battled this over the last 6 months.

I asked my GP about this medication but she said she knew little about it.

I would be grateful for any information regarding this drug please.


Agomelatine is a unique antidepressant because it has effects on the melatonin receptor. Many medications are processed by the liver; initial studies on this med showed that it sometimes increased LFTs (these are blood tests that measure liver function). Other meds also do this...we call it a drug-induced hepatitis...which sounds worse than it is. If there is a small increase in LFTs, all you need to do is continue to monitor the blood tests to make sure it doesn't get worse. If they get too high, you would have to stop the medication.


Once the med is stopped, the LFTs normalize & your liver should recover fully. At present I am not aware of any more severe effects on the liver, but keep in mind this medication is relatively new & hasn't been on the market that long.


Almost all antidepressants can cause insomnia as a side effect which is why most are taken in the morning; however, they can all treat insomnia since that's a symptom of the depression. Melatonin in the brain is closely tied to sleep, so this med may potentially have more beneficial effects for sleep. Sometimes, if people get insomnia when starting a med, it may go away as the body adjusts. The point is to be aware of any positive & negative effects of the med after you start it. If side effects don't go away, you will have to decide with your physician if the benefits of the med outweigh the side effects.


I hope this helps. Good luck & take care.

Customer: replied 5 years ago.

Hi Dr K


I accept what you say about all antidepressants causing insomnia which is why they are taken in the morning, but this one has to be taken at night which is why I am a little worried.


Can I ask, does the liver function test also show the levels of the drug in my system or is that a seperate test?


My biggest concern is that I might become manic again. I was taken off antidepressants (after 17 years of taking various types) in October when I hit a manic episode. At that time I was also on Olanzapine 15mg and this got increased to 20mg, which is the dose I am currently on. The thought of becoming manic again concerns me.



Try to think positively about the medicine. People who worry a lot about side effects tend to get them more. Side effects are minimized by starting on low doses and not being too agggressive with dosage increases. If you notice that it does give you any insomnia, just switch it to the morning. As of now I am not aware of any standardized blood test to measure the amount of agomelatine in your blood.


Becoming manic is a concern with any antidepressant. However, you are on a good dose of olanzapine which has mood stabilizing properties. This medicine can block the manic effects of any antidepressant. Again, going slowly with the dose with help reduce the risk of mania as well.


Any other questions?



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Customer: replied 5 years ago.

No more questions.


Thanks for your answers. I will now, of course, click on the accept button.



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