Is Fluoxetine and Mirtazapine combination any good? (3 complications) 

In this blog post, we are going to answer the question, “Is Fluoxetine and Mirtazapine combination any good?”. Fluoxetine and Mirtazapine both are strong antidepressants and can be used for a number of health-related problems. 

Both of these antidepressants are sometimes used in combination. This blog will cover the safety and efficacy of the concomitant use of Fluoxetine and Mirtazapine. We will also discuss some tips to ensure the proper use of these meds. 

Is Fluoxetine and Mirtazapine combination any good?

The combination of Fluoxetine and Mirtazapine is considered a good one, but it may not be a good choice of treatment for every other individual. The combination of treatment with antidepressants can be a little tricky because of the side effects and tolerability issues associated with these meds. 

However, if your doctor thinks that the combination of Fluoxetine and Mirtazapine can help counteract your mental health-related symptoms then you should definitely trust your doctor and start the treatment, but there’s more to it. 

Some people may not achieve the kind of therapeutic response they hope for. Several surveys suggest that people who tend to misuse meds or forget to take them because of their schedule or simple non-adherence, suffer the most. 

This is because drugs that can affect your brain should be used properly. When they are not, they don’t work in the way you want them to work. Both Fluoxetine and Mirtazapine are considered strong antidepressants and show good results when used alone. 

Monotherapy is usually enough for moderate or even severe mental illnesses, but combination therapy works better for monotherapy-resistant depression. 

When your prescription is handed over to you, now it’s your job to make sure you achieve the maximum therapeutic response from this combination with minimal side effects. This can be achieved by strictly sticking to your doctor’s recommended dose and taking it as many times as directed, no more or less than that. 

What are the side effects associated with the use of Fluoxetine and Mirtazapine? 

Both Fluoxetine and Mirtazapine are associated with some side effects of their own. Let’s look at the side effects individually and then we will pick out the common ones to discuss how the synergistic side effects can be avoided. 

Side effects of Fluoxetine 

Fluoxetine (Common brand name: Prozac) is associated with the following side effects:

• Restlessness 
• Anxiety 
• Drowsiness 
• Dizziness 
• Skin rash
• Muscular pain
• Joint pain
• Headache
• Nausea
• Vomiting 
• Tiredness 
• Sweating 
• Loss of appetite 
• Loss of sexual desire 

Fluoxetine is also associated with some serious side effects, which often require immediate medical attention. These include:

• Allergic reaction associated with symptoms like redness of skin, itching, burning sensation, blisters, blue-purple patches, tightness of chest, wheezing, difficulty in breathing, hoarseness etc. 
• Convulsions 
• Dark grey-brown coloured vomiting
• Tarry or bloody stools
• Eye problems, including pain, swelling, redness, vision changes etc. 
• Abnormal mood changes including, excitement followed by a sudden sadness, erratic behaviour, paranoia etc
• Kidney function abnormalities, including severe pain, the elevation of serum creatinine, the difference in urine output and colour, blood urea nitrogen levels etc. 
• Suicidal behaviour 
• Excessive muscle tremors 

Side effects of Mirtazapine 

Mirtazapine (Common brand name: Remeron) is also associated with some side effects. These include:

• Sleepiness or drowsiness 
• Excessive tiredness or fatigue 
• Dizziness or lightheadedness 
• Xerostomia or dry mouth 
• Anxiety 
• Agitation 
• Confusion 
• Gain of appetite
• Weight gain 
• Gastrointestinal side effects, including nausea, vomiting and diarrhoea/Constipation 

Mirtazapine is also associated with some serious side effects, which may include:

• Allergic reactions associated with symptoms like redness of the skin, itching, burning sensation, blisters, blue-purple patches, tightness of chest, wheezing, difficulty in breathing, hoarseness etc. 
• Convulsions 
• QT prolongation 
• Pain and tightness in the chest
• Arrhythmia 
• Flu-like symptoms 

These side effects can vary from person to person. The most commonly reported side effects are usually gastrointestinal side effects and dizziness. 

Sleep-related side effects are also very common with the use of antidepressants. Make sure you monitor your side effects carefully if you’re being treated with the combination of Fluoxetine and Mirtazapine. 

What are the possible complications associated with the combination of Fluoxetine and Mirtazapine? 

There are some complications that may occur because of the common side effects and the mechanism of action of both of the drugs. Fluoxetine is a selective serotonin reuptake inhibitor (SSRI). It works by inhibiting the reuptake of serotonin by blocking serotonin transporters (SERT). 

This way there is an excess amount of serotonin left to bind with its respective receptors throughout your body. This helps to counteract the symptoms associated with depression and other mental health conditions. 

Mirtazapine, on the other hand, is an atypical antidepressant and it does not work like Fluoxetine. Experts believe that Mirtazapine has a dual mode of action. On one hand, it increases the secretion of serotonin by stimulating the noradrenergic system. 

On the other hand, it also blocks the inhibition of serotonin release by preventing the inhibitory action of the noradrenergic system. This way more and more serotonin is released and the release is not hindered in any way. 

The excess of serotonin elevates your mood, cognition, reward, learning, memory, and various other psychological processes. Now these two drugs, although in different ways, are doing the exact same thing. 

They both are increasing the amount of serotonin, which is an excitatory neurotransmitter, in your brain. This can give rise to a number of complications. Some of these include:

• Serotonin syndrome 
• Psychological complications 
• Metabolic complications 

Serotonin syndrome

As we have just discussed, both Fluoxetine and Mirtazapine are associated with increasing the amount of active serotonin in your body. When taken together, both drugs do their part. They both increase the levels of serotonin in your body. 

If the doses of these drugs are not adjusted, they can make the amount of serotonin unbearably high, which gives rise to the symptoms associated with serotonin syndrome. The syndrome occurs as a result of too much serotonergic activity and it can be of various intensities. 

Some of the symptoms associated with this disturbing syndrome include:

• The rapid change in blood pressure 
• Uncontrollable heartbeat
• Vision problems 
• Auditory and visual hallucinations
• Erratic behaviour 
• Fever with chills
• Muscle Shivering 
• Nervousness 
• Convulsions 
• Confusion 

Psychological complications 

Another main concern is the effect of too much serotonin on your brain. Not just that, we have just observed that both of the drugs are associated with some common psychological side effects like anxiety, agitation, and sleep disturbances. 

These harmful effects can really add up when Fluoxetine and Mirtazapine are used together. Some people suffer from excessive sleepiness which can decrease their mental alertness. 

Some people suffer from insomnia and stay up almost all night. This also affects their energy levels and mental alertness during the daytime. 

Metabolic complications 

Both Fluoxetine and Mirtazapine are associated with some metabolic side effects as well. Several studies have indicated that the concomitant use of Fluoxetine and Mirtazapine can cause weight gain in some people. We all know what kind of a problem weight gain is. 

It can mess up your metabolism and related functions. If it gets out of hand, your body can become insensitive to insulin because of the high amounts of glucose in your blood. This can cause diabetes mellitus and several other kinds of metabolic disorders. 

This is why it is extremely important to make sure that the combination of Fluoxetine and Mirtazapine is the best possible choice of treatment for you and your condition. If there is any other safer and better option available, it should be evaluated. 

There is no way to predict if you’re allergic to any one or both of these antidepressants. Allergies are totally unpredictable in new antidepressant users. 

If you know that you’re allergic to any one of these meds then this combination is definitely not for you. Make sure you start from the lowest effective dose. In this way, any harmful or sudden reaction to this combination will not be severe and can be manageable. 

Conclusion 

In this blog post, we have discussed the concomitant use of Fluoxetine and Mirtazapine. Both of these meds are strong antidepressants and can be used to treat a variety of mental health conditions. The combination is usually considered a good one, but it does come with some possible complications. 

However, if your doctor thinks that the combination of Fluoxetine and Mirtazapine can help counteract your mental health-related symptoms then you should definitely trust your doctor and start the treatment. 

One thing to bear in mind is that improper use of these meds can make your condition even worse. This is why you should always take your meds carefully. Non-adherence is the worst thing you can do to yourself and your mental health. 

FAQs: Fluoxetine and mirtazapine combination 

Is fluoxetine stronger than mirtazapine?

Both Fluoxetine and Mirtazapine are strong antidepressants and they work really well when used individually. However, they both have different mechanisms of action which is why they can affect people differently. When it comes to the research studies, some of them have revealed that clinical data shows Mirtazapine to be more effective in counteracting the symptoms associated with depression. It also works well for depression comorbid with insomnia. However, Fluoxetine is one of the most commonly prescribed antidepressants and it has done wonders for some people. 

Can you take other antidepressants with mirtazapine?

Yes, you can take other antidepressants with Mirtazapine, but only if prescribed by your healthcare provider. Mirtazapine can be paired with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). However, monotherapy of Mirtazapine is also considered sufficient in some cases. 

What medications should not be taken with mirtazapine?

• Monoaminoxidase inhibitors (MAOIs). The combination use can increase the risk of serotonin syndrome. 
• Non-steroidal anti-inflammatory drugs (NSAIDS). The combination use can increase the risk of bleeding. 
• Pimozide. The concomitant use can increase the plasma concentration(availability of a drug in the blood) of pimozide to much higher levels. It can result in life-threatening arrhythmia.
• Controlled substances, including all narcotic analgesics. The concomitant use can cause severe psychological side effects. 
• Mood stabilisers 
• Alcohol 

What is the strongest antidepressant?

According to research studies, tricyclic antidepressants are the strongest antidepressants. However, they are not used as the first line of depression therapy because of the side effects they produce. This is why the newer antidepressants replaced TCAs and they are now used as the first line of therapy. Newer antidepressants are selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). 

What works well with mirtazapine for anxiety?

Several studies suggest that Mirtazapine can be used with Paroxetine for the safe and effective treatment of generalised anxiety disorder (GAD) and social anxiety disorder (SAD). However, other SSRIs can also be combined with Mirtazapine for the treatment and management of symptoms associated with anxiety. Make sure you stick to your doctor’s directions for a safe and effective therapeutic outcome. 

References 

• Drug Interactions between mirtazapine and Prozac https://www.drugs.com/drug-interactions/mirtazapine-with-prozac-1640-0-1115-648.html#:~:text=Using%20FLUoxetine%20together%20with%20mirtazapine,shivering%20or%20shaking%2C%20blurred%20vision%2C
• F Benazzi. Int J Geriatr Psychiatry. (1998) – Serotonin syndrome with mirtazapine-fluoxetine combination https://pubmed.ncbi.nlm.nih.gov/9695042/
• National Library of Medicine – Mirtazapine https://medlineplus.gov/druginfo/meds/a697009.html 
• Prozac Capsule – Uses, Side Effects, and More https://www.webmd.com/drugs/2/drug-6997/prozac-oral/details