Can I prescribe Duloxetine (Cymbalta) 30 mg or Amitriptyline (Elavil) 25 mg at bedtime to a patient already taking Remeron (Mirtazapine) for mental health?

From the Guidelines

Prescribing duloxetine (Cymbalta) 30 mg or amitriptyline (Elavil) 25 mg to a patient already taking mirtazapine (Remeron) is not recommended due to the risk of serotonin syndrome and increased side effects. The patient is already on mirtazapine (Remeron), which is a potent and well-tolerated antidepressant that promotes sleep, appetite, and weight gain, with an initial dosage of 7.5 mg at bedtime and a maximum dosage of 30 mg at bedtime 1. Adding another serotonergic agent like duloxetine or amitriptyline could increase the risk of serotonin syndrome, a potentially serious condition characterized by agitation, confusion, rapid heart rate, dilated pupils, muscle rigidity, and elevated temperature.

Some key points to consider when managing a patient on mirtazapine include:

• Optimizing the mirtazapine dose first if additional treatment for depression or anxiety is needed
• Considering switching to a different medication rather than adding another serotonergic agent
• Exploring non-serotonergic options like gabapentin for pain management
• Carefully weighing the risk-benefit ratio and closely monitoring for signs of serotonin syndrome if combination therapy is considered
• Being aware of potential worsened side effects like sedation, dry mouth, constipation, and weight gain with combination therapy

Given the potential risks, a psychiatric consultation would be advisable before attempting to combine these medications, to ensure the best possible outcome for the patient in terms of morbidity, mortality, and quality of life.

From the Research

Prescribing Duloxetine or Amitriptyline with Remeron

• As a PCP, you are considering prescribing Duloxetine (Cymbalta) 30 mg or Amitriptyline (Elavil) 25 mg at bedtime to a patient already taking Remeron (Mirtazapine) for mental health.
• According to the study 2, combining venlafaxine and mirtazapine in the treatment of depression has shown promise, with a response rate of 81.8% and a remission rate of 27.3%.
• However, it is essential to note that the study 2 used venlafaxine, not duloxetine, in combination with mirtazapine.
• Another study 3 found that antidepressant combinations, such as venlafaxine-XR plus mirtazapine, were associated with a higher non-adherence rate than monotherapy.
• Amitriptyline has been shown to be effective in migraine prevention 4 and may be beneficial for patients with comorbid insomnia due to its sedating effect.
• Duloxetine has also been used to treat depression and may be effective in patients with comorbid depression and migraine 4.
• When considering prescribing either medication, it is crucial to weigh the potential benefits and risks, including the possibility of increased non-adherence and side effects.

Considerations for Prescribing

• Before prescribing Duloxetine or Amitriptyline, consider the patient's individual needs and preferences, as well as their medical history and current medications.
• Monitor the patient closely for potential side effects and adjust the treatment plan as needed.
• The study 5 suggests that switching or augmenting antidepressant medications can be an effective strategy for patients with treatment-resistant depression, but it should be tailored to the individual patient's needs.
• It is also important to consider the potential for non-adherence, as reported in the study 3, and to closely monitor the patient's treatment regimen.