Remeron vs Prozac

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For patients with major depressive disorder (MDD) or other types of depression, certain medications that modify the levels of brain chemicals associated with mood—known as neurotransmitters—can assist in stabilizing depressive episodes and managing symptoms. Remeron and Prozac are two such drugs commonly prescribed for depression. They each impact different neurotransmitters in the brain, but both have therapeutic effects on patients suffering from depression. Remeron is classified as a noradrenergic and specific serotonergic antidepressant (NaSSA), primarily affecting norepinephrine and serotonin receptors to enhance their activity. On the other hand, Prozac is a selective serotonin-reuptake inhibitor (SSRI), working mainly by increasing levels of serotonin.

What is Remeron?

Mirtazapine (the generic name for Remeron) belongs to a class of antidepressants known as tetracyclic antidepressants. It was approved by the FDA in 1996 and works differently than SSRIs such as fluoxetine. Mirtazapine increases levels of norepinephrine and serotonin in the brain, but it does so by blocking receptors that when activated, inhibit their release. This effectively means there's more free norepinephrine and serotonin available for neurons to use. Moreover, while both drugs are used to treat depression, mirtazapine also has strong antihistamine effects making it useful for those with sleep problems or anxiety-related conditions. Unlike Prozac which primarily affects serotonin with minimal influence on dopamine and norepinephrine, Remeron impacts multiple neurotransmitters equally resulting in a different side effect profile.

What conditions is Remeron approved to treat?

Remeron is approved for the treatment of different variations of depression:

  • Major depressive disorder (MDD), also known as unipolar depression
  • Depressive episodes associated with bipolar disorder
  • In some cases, it's used off-label to treat a variety of conditions such as anxiety disorders and insomnia.

How does Remeron help with these illnesses?

Remeron, also known as mirtazapine, manages depression by increasing the amount of both serotonin and norepinephrine in the synapses of the brain. It does this through a dual action: it prevents these neurotransmitters from being reabsorbed by neurons (a similar mechanism to Prozac), and it also enhances their release. Serotonin is involved in mood regulation, cognition, memory, sleep patterns among others, while norepinephrine plays key roles in attention and response actions. Individuals with depression are believed to have relatively lower levels of these neurotransmitters. Thus Remeron can alleviate depressive symptoms by elevating both serotonin and norepinephrine levels thereby helping patients manage their condition more effectively than simply boosting one neurotransmitter alone.

What is Prozac?

Prozac is a brand name for fluoxetine, which is a selective serotonin reuptake inhibitor (SSRI), meaning it increases the levels of serotonin in the brain by reducing their reabsorption. It was first approved by the FDA in 1987 and has been widely used since then to treat major depressive disorder, obsessive-compulsive disorder (OCD), bulimia nervosa, panic disorder, and premenstrual dysphoric disorder. As Prozac is an SSRI antidepressant, it does not have significant effects on norepinephrine or dopamine reuptake. This focus on serotonin means its side-effect profile differs from that of other types of antidepressants such as Remeron; specifically, it doesn't cause significant weight gain or sedation but can lead to sexual dysfunction – common side effects encountered with drugs like Remeron that additionally influence norepinephrine and dopamine pathways. The specific action on serotonin can be advantageous in treating depression symptoms, especially among patients who do not respond favorably to mixed neurotransmitter drugs like Remeron.

What conditions is Prozac approved to treat?

Prozac, a widely recognized antidepressant also known as fluoxetine, has been approved for the treatment of:

  • Major depressive disorder (MDD)
  • Obsessive-compulsive disorder (OCD)
  • Bulimia nervosa
  • Panic disorder

In addition to these specific conditions, Prozac is often used in the management of premenstrual dysphoric disorder (PMDD).

How does Prozac help with these illnesses?

Serotonin is a neurotransmitter that plays significant roles in many processes in the body, such as regulating mood, appetite and sleep. Low levels of serotonin have been associated with depression and anxiety disorders. Prozac works by increasing the levels of serotonin available in your brain, thereby alleviating some symptoms of depression and related conditions. It accomplishes this through its action as a selective serotonin reuptake inhibitor (SSRI). Prozac's effectiveness has made it one of the foremost choices when treating depressive disorders. Unlike Remeron which also influences norepinephrine and histamine receptors besides serotonin - leading to more potential side effects - Prozac primarily targets only the latter making it better tolerated for many patients.

How effective are both Remeron and Prozac?

Both mirtazapine (Remeron) and fluoxetine (Prozac) have established histories of effectiveness in treating patients with depression, being approved by the FDA in 1996 and 1987 respectively. Given their different mechanisms of action, they may be prescribed under varying circumstances. Mirtazapine acts as an antagonist at certain types of adrenergic, serotonin, and histamine receptors while fluoxetine is a selective serotonin reuptake inhibitor (SSRI). Their respective efficacy was directly compared in a double-blind clinical trial conducted in 2001; both drugs were found to exhibit similar efficacy in managing symptoms of depression along with comparable safety profiles.

In terms of side effects, mirtazapine tends to cause more weight gain than fluoxetine but less sexual dysfunction - an adverse effect commonly associated with SSRIs like Prozac. A study published in The Journal of Clinical Psychiatry showed that mirtazapine led to significantly fewer sexual side effects than fluoxetine.

A review from the Cochrane Database System Review on mirtazapine indicated it's effective for treating depression starting from the first week itself. Like many other antidepressants, it is well-tolerated among various populations including elderly people or those suffering from insomnia due to its sedative properties.

Fluoxetine's efficiency has been widely studied since it became the world's most-prescribed antidepressant drug after its introduction as the pioneer SSRI-class antidepressant. It not only alleviates depressive symptoms but also appears promising for reducing suicidal ideation and behavior at optimal doses around 20 mg/day.

While Remeron might be considered as one alternative when first-line treatments such as Prozac fail or aren't tolerated well by patients due to specific reasons like sexual dysfunction or lack thereof response towards treatment with SSRIs alone.

abstract image of a researcher studying a bottle of drug.

At what dose is Remeron typically prescribed?

Oral dosages of Remeron (Mirtazapine) typically start at 15 mg/day and can range up to 45 mg/day for the treatment of major depressive disorder in adults. Research suggests that a starting dose of 15 mg/day is usually effective, but this may be increased after several weeks if no improvement is seen. For children and adolescents, the use and dosage should be determined by a healthcare professional based on their weight, age, and overall health condition. The maximum dosage for any patient should never exceed 45 mg/day without consultation with a healthcare provider.

At what dose is Prozac typically prescribed?

Prozac treatment is typically started at a dosage of 20 mg/day. The dose can then be increased to 40 mg/day, usually taken in the morning. For some patients, it may be advisable to divide the daily dose into two separate doses, spaced about 12 hours apart. Maximum dose is 80 mg/day divided into two or three doses and which could be tested if there is no response to treatment at lower dosages after a few weeks. As with all medications, always follow your doctor's instructions when adjusting your Prozac dosage.

What are the most common side effects for Remeron?

When comparing Remeron (Mirtazapine) to Prozac (Fluoxetine), there are several common side effects you may experience:

  • Anxiety
  • Dizziness and somnolence
  • Increased appetite as opposed to anorexia
  • Dry mouth or increased salivation
  • Constipation rather than diarrhea
  • Weight gain instead of weight loss
  • Tremors, although they're less common with Mirtazapine
  • Fatigue or asthenia
  • Insomnia can occur but is more likely with Fluoxetine due to its activating properties.
  • Nausea, which could potentially lead to vomiting.

Less common but serious side effects include abnormal dreams, decreased libido, impotence, rash, sweating excessively. It also has the potential for causing Serotonin Syndrome - a life-threatening condition that requires immediate medical attention. Always consult your physician before starting any new medication regimen.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Remeron?

When comparing Remeron to Prozac, it's important to understand that both medications can potentially cause serious side effects. For Remeron (mirtazapine), these may include:

  • Increased suicidal thoughts or actions, particularly in people under the age of 25
  • Signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat
  • Changes in vision such as blurred vision and eye redness
  • Rapid heart rate or fluttering in chest indicating possible cardiovascular complications
  • Low sodium levels - symptoms might include headache, confusion, slurred speech, severe weakness and unsteadiness
  • Severe nervous system reaction - stiffness in muscles along with high fever and excess sweating could indicate a life-threatening condition called Neuroleptic Malignant Syndrome.

If you experience any signs of serotonin syndrome while taking Remeron — agitation, hallucinations, rapid heartbeat (tachycardia), fever over 38 degrees Celsius/100.4 Fahrenheit , excessive sweating (diaphoresis) muscle rigidity/stiffness/spasms/twitches (myoclonus), coordination problems—seek medical attention immediately.

Just like with any medication changeover from one antidepressant to another i.e., Prozac to Remeron or vice versa requires careful supervision by a healthcare professional due to potential withdrawal effects &/or adverse drug interactions.

What are the most common side effects for Prozac?

Possible side effects of Prozac include:

  • Dry mouth and sore throat
  • Unusual sweating or feeling hot
  • Nausea, upset stomach, diarrhea
  • Insomnia or unusual dreams
  • Weight changes (loss or gain)
  • A decrease in libido or ability to perform sexually
  • Tremors, feeling nervous, restlessness
  • Fast heart rate (tachycardia)
  • Cognitive disturbances such as confusion and agitation. In rare instances, hostility may occur.

Are there any potential serious side effects for Prozac?

While Prozac is typically safe for use, it can occasionally cause serious side effects that you should look out for:

  • Allergic reactions or severe skin reactions. Symptoms include hives, itching, fever, swollen glands, difficulty breathing or swallowing due to face and throat swelling
  • Unusual changes in mood or behavior—such as agitation, hostility, panic attacks—and new or worsening depression
  • Increased suicidal thoughts or actions especially among adults under 25 years old during the initial stages of treatment
  • Serotonin syndrome: symptoms may include agitation; hallucinations; rapid heartbeat; fever; excessive sweating; shivering or shaking; muscle twitching or stiffness; loss of coordination
  • Vision problems such as blurred vision and seeing halos around lights
  • Abnormal bleeding: this includes unusual bruising and wounds that do not stop bleeding even after applying pressure.

If any of these occur while taking Prozac you should seek immediate medical attention. It's important to remember that everyone responds differently to medications so keep your doctor informed about any adverse side effects.

Contraindications for Remeron and Prozac?

Both Remeron and Prozac, like most other antidepressant medications, may increase symptoms of depression in some individuals. If you observe your depression intensifying or an uptick in suicidal thoughts, ideation or behavior, it is crucial to seek immediate medical attention.

Neither Remeron nor Prozac should be taken if you are on, or have recently been on monoamine oxidase (MAO) inhibitors. It's essential that your physician knows about all the medications you're taking; MAOIs will require a clearance period of approximately 5 weeks from your system to avoid hazardous interactions with both Remeron and Prozac.

How much do Remeron and Prozac cost?

For the brand name versions of these drugs:

  • The price of 30 tablets of Remeron (15 mg) averages around $250, which works out to approximately $8.33/day.
  • The price of 30 capsules of Prozac (20 mg) is about $570, working out to roughly $19/day.

Thus, if you are in the higher dosage range for Remeron (i.e., 45 mg/day), then brand-name Prozac may be less expensive on a per-day treatment basis. Please note that cost should not be a primary consideration in determining which of these drugs is right for you.

For the generic versions:

  • Mirtazapine (generic version of Remeron), available in packs from 7 up to 100 tablets with strengths from 15mg up to 45mg, can cost as low as approximately $0.24/day and might go up to about $3.00 per day depending upon your required dosage and tablet pack size.
  • Fluoxetine (the generic form of Prozac) comes in packages ranging from 10 up to even more than a thousand capsules at strengths generally between 10mg and misses or exceeds only slightly beyond maximum daily recommended doses such as those exceeding around forty milligrams; costs start as insignificantly small amounts like five cents per day if bought upfront covering long periods such as months or years but usually don't exceed ninety cents each day under normal circumstances.

Popularity of Remeron and Prozac

Mirtazapine, available in generic form and under the brand name Remeron, was estimated to have been prescribed to about 1.8 million people in the US in 2020. Mirtazapine made up just over 4% of antidepressant prescriptions. Notably, it is considered an "atypical" antidepressant due to its unique mechanism of action that sets it apart from more common types like SSRIs or SNRIs. The use of mirtazapine has seen a steady increase since the early 2000s.

Fluoxetine, including branded versions such as Prozac, was prescribed to approximately 4.7 million individuals across the USA during the same year - this accounted for nearly one-fifth of all SSRI prescriptions and just shy of one-tenth of total antidepressant prescriptions in general. Over the past decade, fluoxetine's prevalence has remained fairly stable with only minor fluctuations observed.


Both Remeron (mirtazapine) and Prozac (fluoxetine) have strong reputations for effectiveness in the treatment of depression, supported by numerous clinical studies and meta-analyses indicating superior efficacy compared to placebo treatments. Sometimes, both drugs may be used concurrently, but such decisions require careful physician consideration due to potential interactions. Each drug operates differently - while Prozac primarily acts on serotonin and norepinephrine, Remeron's mechanism is more complex as it increases availability of both serotonin and norepinephrine without inhibiting their reuptake.

Prozac is often considered a first-line treatment option for depression, whereas Remeron is frequently employed when patients do not respond optimally to initial SSRI antidepressants like Prozac or need help with insomnia which can accompany depression.

Both medications are available in generic form offering cost savings especially beneficial for those paying out-of-pocket. Both Remeron and Prozac may necessitate an adjustment period before noticeable effects occur.

While side effect profiles are generally similar between these two drugs with good overall tolerability reported, Remeron tends to cause more significant weight gain than Prozac. Patients starting either medication should monitor their mood closely; any signs of worsening depression or emergence of suicidal thoughts must prompt immediate medical attention.