Can a patient take 7.5 mg of mirtazapine for a couple of weeks before increasing to 15 mg?

Starting Mirtazapine at 7.5 mg Before Increasing to 15 mg

No, the patient should start directly at 15 mg once daily rather than beginning at 7.5 mg, as the FDA-approved starting dose is 15 mg and lower doses may provide inadequate antidepressant effect while potentially causing more sedation. 1

FDA-Approved Dosing Recommendations

• The FDA label explicitly states that the recommended starting dose is 15 mg once daily, administered orally, preferably in the evening prior to sleep 1
• Dose changes should not be made in intervals of less than 1 to 2 weeks to allow sufficient time for evaluation of response to a given dose 1
• If patients do not have an adequate response to the initial 15 mg dose, the dose can be increased up to a maximum of 45 mg per day 1

Why 7.5 mg is Not Recommended for Depression Treatment

• The 7.5 mg dose is associated with MORE sedation, not less, due to mirtazapine's unique pharmacology 2, 3
• At subtherapeutic dosages below 15 mg, increased sedation is more commonly reported, and this sedation is substantially reduced when the drug is used in appropriate dosages (≥15 mg) from the beginning of treatment 2
• The 7.5 mg dose is primarily used off-label for insomnia, not for treating major depressive disorder 4

Monitoring Timeline After Starting Treatment

• The American College of Physicians recommends beginning to assess patient status, therapeutic response, and adverse effects within 1-2 weeks of treatment initiation 5
• If the patient does not have an adequate response within 6-8 weeks, treatment modification is strongly recommended 5
• Mirtazapine shows an early onset of action, with significant improvements noted as early as 1-2 weeks after starting treatment at therapeutic doses 6, 2

Common Pitfalls to Avoid

• Starting too low (7.5 mg) paradoxically causes more sedation due to predominant H1 receptor antagonism at lower doses, while higher therapeutic doses engage the noradrenergic mechanisms that counteract sedation 2, 3
• Waiting too long between dose adjustments—the FDA recommends evaluating response every 1-2 weeks, not waiting longer 1
• Failing to screen for bipolar disorder before initiating treatment, as required by FDA labeling 1

Appropriate Clinical Scenarios for Different Doses

• 15 mg starting dose: Standard for major depressive disorder treatment 1, 7
• 30-45 mg maintenance dose: For patients requiring higher doses after inadequate response to 15 mg 1, 7
• 7.5 mg dose: Reserved for off-label use in insomnia only, not for depression treatment 4