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Mirtazapine Dosage And Dosing Considerations

Last Updated: February 28, 2024

Authored by Sharon Levy, MD, MPH

Reviewed by Dr. Ash Bhatt

Similar to other medications, Remeron dosage varies from one patient to another based on several factors such as weight and age. In addition, mirtazapine dosage adjustments are also possible for patients with renal or liver impairments. This article discusses all that a patient needs to know about the Remeron dosage.

Remeron Dosing Forms And Strengths Available

Mirtazapine dosage strengths range from 15mg to a maximum of 45mg. Oral administration is the only method of administering the drug. However, the National Institute of Health warns that the mirtazapine class of drugs needs to undergo more studies to understand the relative benefits or potential harm of varying doses.

All mirtazapine tablets marketed under the Remeron brand name are film-coated, oval, and biconvex. Each tablet dose can be divided into two equal parts. These tablets are packed in blisters or bottles. The differences between Remeron branded tablets are discussed in the table below.

Dosage Color Imprint
15mg yellow ‘MSD’ on one side, ‘TZ3’ on the other side (on both sides of the score)
30mg red-brown ‘MSD’ on one side, ‘TZ5’ on the other side (on both sides of the score)
45mg white ‘TZ7’ on one side and ‘Organon’ on the other side

The generic versions of Reneron tablets vary in colors, forms, and imprints, depending on the manufacturer.

Mirtazapine Dosage For Sleep

Antidepressants such as Remeron may be prescribed to manage conditions such as insomnia since they pose far less side effects than benzodiazepines. Low dose mirtazapine of between 7.5 mg and 15 mg produces its effects on sleep by antagonizing alpha 2 adrenergic receptors on both norepinephrine and serotonin (5-HT) presynaptic axons. Serotonin receptors directly promote healthy sleeping patterns.

Mirtazapine Dosage For Anxiety

In a 12-week study published in the Journal of Psychopharmacology, a fixed 30mg mirtazapine doses showed a 63.3% reduction of symptoms of a generalized anxiety disorder (GAD). In other words, this dose of Remeron pills can be taken for the effective management of anxiety.

remeron dosage for appetite increase

Remeron Dosage For Appetite

Studies by the US National Library of Medicine have shown that mirtazapine doses of as low as 7.5mg per day before bedtime may improve the appetite of patients. As a result, one of the most common Remeron side effects is weight gain. Mirtazapine dosages of as low as 12.8 mg per day were also found to increase the weight of patients directly. That is why the relationship between mirtazapine and weight gain may be directly linked to the increase in appetite. Still, this issue requires further investigation.

Remeron Dosage For Depression

Remeron dosage for depression starts from 15 mg a day as a single-administered dose, or as a divided one. The effective dose ranges from 15 mg to 45 mg a day. Only a doctor can decide on what effective dose should be.

Mirtazapine Dosage Adjustments

The following are the recommended Remeron doses for patients with different stages of kidney impairment. However, it is still important to discuss with a doctor on the best dosage amounts and schedule so that the doctor to make the final decision.

Normal kidney function 15-35 mg in single or two divided doses
Moderate reduction in kidney function No adjustment
Severe reduction in kidney function 15 mg, increase carefully
End-stage kidney disease 15 mg, increase carefully
Patients undergoing RRT (HD, PD, & HDF) 15 mg, increase carefully

Mirtazapine Maximum Dose

The mirtazapine maximum dose that can be prescribed by a doctor is 45mg per day. The mirtazapine MOA (mechanism of action) usually lasts about 20 to 40 hours. Furthermore, treatment with an adequate mirtazapine dose should result in a positive response within 2-4 weeks. Taking a higher Remeron dose is not recommended and is more likely to result in harmful side effects and overdose.

The Best Time To Take Mirtazapine

The best time to take a Remeron pill is right before going to bed. In addition to when to take mirtazapine, patients should also know that it is recommended that the drug be taken at the same time every day. Doctors may suggest splitting the Remeron dose and taking it twice a day once in the morning and evening. All tablets should be taken orally without chewing with either water or some juice. The patients should always take medicine as instructed by their doctors and consult their doctor if unsure.

when to take missed dose of Remeron


Mirtazapine Missed Dose

In case of a missed dose, do not take a double dose to make up for the one that has been missed if the Remeron pills are normally taken once a day. On the other hand, if the dosage is taken twice a day, and it was forgotten in the morning, the missed morning mirtazapine dose can be taken together with the evening one. If the evening dose is missed, do not take it in the morning, just continue with the normal dosing routine.

Remeron LD50

The Remeron LD50 dosage is 830mg/kg in male Swiss mice. There are no human trials reported on LD50.

Can One Overdose On Mirtazapine?

Yes, one can overdose on mirtazapine. The most common symptoms from an overdose on Remeron pills without taking other medicines or alcohol are an increased heart rate, fainting drowsiness, and disorientation. And even though the mirtazapine high effects may not cause euphoria. Instead, the drug can cause physical dependence.

What Patients Should Know When Taking Remeron

The three Remeron dosing forms are tablets, orodispersible tablets, and oral solution. The drug’s maximum dosage that can be prescribed is 45mg per day. In cases of overdosing or missed doses, precautions should be taken to avoid adverse effects. Remeron abuse should be avoided and people who are already addicted should seek professional assistance from rehabilitation centers. These facilities offer a range of addiction treatment services for patients with different needs.

Page Sources

  1. Remeron. Package leaflet: Information for the patient. https://mri.cts-mrp.eu/human/downloads/NL_H_0132_007_FinalPL.pdf.
  2. Sleep and mental health. Harvard Health Publishing. 2019. https://www.health.harvard.edu/newsletter_article/sleep-and-mental-health.
  3. Gambi, F., De Berardis, D., Campanella, D., Carano, A., Sepede, G., Salini, G., … Ferro, F. M. Mirtazapine treatment of Generalized Anxiety Disorder: a fixed dose, open label study. Journal of Psychopharmacology, 2005: 19(5), 483–487. doi https://doi.org/10.1177/0269881105056527. https://journals.sagepub.com/doi/10.1177/0269881105056527#articleCitationDownloadContainer.
  4. Shibahara H, Ito T, Uematsu N, Imai E, Nishimura D. Low-dose mirtazapine improved nausea and appetite loss during S-1 therapy. Gan to Kagaku ryoho. Cancer & Chemotherapy. 2012; 39(1): 143-5. https://www.ncbi.nlm.nih.gov/pubmed/22241371.
  5. Nagler EV, Webster AC, Vanholder R, Zoccali C. Antidepressants for depression in stage 3-5 chronic kidney disease: a systematic review of pharmacokinetics, efficacy and safety with recommendations by European Renal Best Practice (ERBP). Nephrol Dial Transplant. 2012; 27(10): 3736-45. doi: 10.1093/ndt/gfs295. https://www.ncbi.nlm.nih.gov/pubmed/22859791.
  6. Mirtazapine. Drug Bank. https://www.drugbank.ca/drugs/DB00370.

Published on: February 28th, 2024

Updated on: February 28th, 2024

About Author

Sharon Levy, MD, MPH

After successful graduation from Boston University, MA, Sharon gained a Master’s degree in Public Health. Since then, Sharon devoted herself entirely to the medical niche. Sharon Levy is also a certified addiction recovery coach.

Medically Reviewed by

Dr. Ash Bhatt

Throughout his professional life, Dr. Bhatt has been conferred with diplomate status by the American Board of Psychiatry and Neurology, certifying him in both adult and child/adolescent psychiatry. His experiences in emergency rooms, frequently encountering patients with simultaneous health and addiction issues, directed his attention to these specific fields.


Leave a comment

  • Lenore
    Is it possible to take7.5mg or 15mg of mirtazapine daily and NOT gain weight. If not, how much weight gain is to be expected?

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