Living with Bipolar Disorder: Antipsychotic Medication (Quetiapine)

Medication Explained: Quetiapine (Seroquel) 💊

Background

Quetiapine is a medication that works in the brain in the treatment of Bipolar Disorder (and also Depression & Schizophrenia). It is known as a second-generation antipsychotic (SGA) or atypical antipsychotic. The second-generation antipsychotics were rolled out in the 70s, some 20 years or so after the first-generation of antipsychotics were introduced, with more added throughout the 80s and up until 1998. In short, first-generation antipsychotics focused on the monoamine Dopamine, and blocked the D2 Receptor, Dopamine Type 2. Where as second-generation antipsychotics focus primarily on the 5HT2A receptor. This is a receptor for another monoamine, Serotonin. It hasn’t yet been concluded if the first generation or second generation perform better, but first-generation medication brings further complications with taking it than second-generation medication. Reports of Parkinson’s and Tardive Dsykinesia are but two illness that their onset has been accredited to the administration of typical, first-Generation antipsychotics.

Quetiapine also has an impact on Stage 2 non-REM sleep along with non-REM sleep in general. By doing this it can improve your sleep quality and reduce the time it takes to fall asleep. It can also alleviate some feelings of anxiety and or depression you may have, to enable you to get a better nights sleep. However, Quetiapine is not prescribed for insomnia or classed as a sleep aid medication. It has a strong sedative effect which can interfere with concentration during the day.

In bipolar therapy, it has interactions that are positive for treatment of what are classed as “positive” symptoms. Positive in this sense due to the fact that they relate predominantly within mania. These are disordered thoughts, visual and audio hallucinations, along with delusions of grandeur and not being concerned or possibly aware with what tomorrow will bring. Some people have believed that they were immortal and impervious to pain and suffering. You can form a picture in your head of the scenarios and high risk activities undertaken to land a person in one of these particular predicament.

Administration of either 1st or 2nd generation will have no impact on your illness in the sense of it being a cure. Nor will they alter the frequency or aggression of episodes. They are purely used to assist you from day to day and help you cope living with your mental illness.

Mode of Action

Quetiapine, in theory, works by restoring chemical equilibrium (evenly balanced) in the brain. It does this by rebalancing the levels needed of dopamine and serotonin in your brain. These levels being in equilibrium are theorised to be significant components to improve thinking, mood, and behaviour.

If the patient is experiencing issues with hallucinations for example, it’s highly likely that what they are experiencing is being brought on by excessive levels of Dopamine. In conjunction with the hallucinations it is also common to observe a person experiencing delusions too. Thirdly, having excessive amounts of Dopamine in the brain can trigger involuntary muscle movements in a person. Moreover if this isn’t addressed, potentially this can cause, theoretically in later life, muscle issues and complications. This is theorised by ‘The Dopamine Hypothesis’. As the mechanics of Bipolar are still unknown, this principle is applied.

Experts aren’t exactly sure how atypical antipsychotics work but they appear block certain chemical receptors in the brain, affecting levels of various neurotransmitters such as dopamine, acetylcholine, noradrenaline, or serotonin.

Atypical antipsychotics appear to have a higher affinity for serotonin receptors and a lower affinity for dopamine receptors than typical antipsychotics. However, the 5-HT2A receptors they block are in the Mesocortical Pathway and they are found on inhibitory neurons responsible for Dopaminergic neuron regulation. As these neurons don’t receive any inhibitory signal, this actually raises the amount of Dopamine in the mesocortical pathway which helps in the negative symptoms of psychosis. So, indirectly they impact on your Dopamine within having a primary interaction with the fundamental mechanisms of it.

Unfortunately, the specifics of Quetiapine’s mode of action with regards to how this happens, is still to be fully understood. Research is currently on going. There is though, a very credible explanation for the process and I don’t think that it will be long until they figure it out. So, the researchers explained that from the evidence they have collated, early indications show a model, the model identified where there is an increase on the dopamine D2/3 receptor levels in the striatum (part of the brain responsible for decision making). It’s here you would have an increase dopaminergic neurotransmission, and this in theory, indicates that all roads lead you to mania (this transmission links to fear, addiction, mood and stress). So, basically the brain would be flooded with these chemicals and overload the senses which cause a shift in the mind so it’s current pathway and focus is hijacked and it’s kidnapped by itself in essence to be reacquainted, subjected and treated to the company of the Bipolar Mania phase. So it deprives the volume available, in turn it doesn’t satisfy the supply whilst increased dopamine transporter (DAT) levels in the striatum would expect, thusly meaning that reduce dopaminergic function and arguably be the cause of depression, as the brain is trying to recycle the dopamine, it doesn’t have, to recycle as it is over the place. It’s such a fine line to balance.

Don’t quote me on this (this is an extremely simplified version of events), but I see it as this; we don’t produce any more volume of chemicals in the brain like serotonin or dopamine for example. We recycle them. So our biochemistry and our reactions in the brain are continuously occurring. So, the basics of the process (very much simplified explanation) is that, our chemical compound, X, is flowing around the brain until it comes in to contact with this certain receptor, which absorbs X, from where it is then moved across cell membranes by the transporter. From here, either another cycle will occur or it is stored and so on and so fourth.

When we encounter an Imbalance in the chemical equilibrium in the brain or body. It’s like getting in or out the bath after 10 pints! The process of the chemical reactions are still operating albeit without the chemical and its this, it’s this incident that is the cause for illness*.

*Once again, this is my theory and not fact or holds any scientific credence

Administration & Dosage

Quetiapine is more often than not taken orally via a tablet. But, in some cases it can also be injected, but this method is extremely rare. Due to the tablets being lipid soluble (ability to transfer from an oil to a liquid), you absorb these through your digestive tract. This means that there is an easy pathway across the blood–brain barrier and also, the placental barriers. In the case of Bipolar Disorder, and my own personal experience, Quetiapine is introduced little by little. I’m not sure what dose I started on but I was taking a tablet in the morning and then another just before bed. For the purpose of this explanation, we’ll say 100mg morning and 150mg at night. I will point out that, at night I took Mirtazapine too, 15mg of it, and Sodium Valproate also with a dose of 1,500mg. So far so good and I don’t have any bad words to say about Quetiapine or report any inconveniences it caused. I must say that I added a few extra pounds at first, but it has now after 18months plateaued in the past few months. I changed Depakote to Lithium in February 2022, so with a combined intake of lithium, Mirtazapine and Quetiapine ,so single one out isn’t possible. You do get cravings (or I did) for fried, fatty foods. Coupled with those periods of bipolar when turning the oven on or even opening the fridge door is not happening, well, you know the score. So getting back to dosage, when you speak to your psychiatrist and you are able to say you haven’t experienced any negative effects or the medication didn’t raise any questions or concerns for you, your medication dosage can be increased by your psychiatrist to reach your therapeutic level. My experience of this is that it was done by small increments at time. My night time dose was increased to 250mg and as of last week I had a further increase of 50mg. My total dosage is now 400mg daily. This dose can be increased to up to 800mg. This gives me comfort knowing that I have, in a different perspective, support from my medication to contain my illness from the dose that is on offer.