A 56-year-old woman comes to the office for a follow-up. Six months ago, the patient was diagnosed with major depressive disorder during an evaluation for low energy, poor sleep, weight gain, and difficulty concentrating at work. She was initially treated with escitalopram, but her depressive symptoms were only slightly improved after 2 months of treatment. Her medication was switched to venlafaxine, which was subsequently titrated to maximal therapeutic dosage over the course of 3 months. The patient reports that her depression has improved with treatment, although she still has occasional insomnia. Her energy has increased back to baseline level; she now feels motivated to exercise and has lost 5 pounds. The patient has no other medical conditions and takes no other medications. She does not use tobacco, alcohol, or illicit drugs. Which of the following should be monitored at this visit?

Question

A 56-year-old woman comes to the office for a follow-up.  Six months ago, the patient was diagnosed with major depressive disorder during an evaluation for low energy, poor sleep, weight gain, and difficulty concentrating at work.  She was initially treated with escitalopram, but her depressive symptoms were only slightly improved after 2 months of treatment.  Her medication was switched to venlafaxine, which was subsequently titrated to maximal therapeutic dosage over the course of 3 months.  The patient reports that her depression has improved with treatment, although she still has occasional insomnia.  Her energy has increased back to baseline level; she now feels motivated to exercise and has lost 5 pounds.  The patient has no other medical conditions and takes no other medications.  She does not use tobacco, alcohol, or illicit drugs.  Which of the following should be monitored at this visit?

Quizplus · Accepted Answer

Serotonin-norepinephrine reuptake inhibitors (SNRIs) (eg, venlafaxine, duloxetine) are frequently prescribed as next step treatment after an adequate trial of a selective serotonin reuptake inhibitor (SSRI) (eg, escitalopram) fails. Many SNRIs, including venlafaxine, are associated with dose-dependent increases in diastolic and systolic blood pressure. Blood pressure should be assessed before starting an SNRI and regularly monitored throughout treatment. As a class, SNRIs inhibit the reuptake of both serotonin and norepinephrine. Venlafaxine has the unique property of possessing significantly higher affinity for the serotonin transporter relative to the norepinephrine transporter, which results in venlafaxine behaving like an SSRI at lower doses and demonstrating significant norepinephrine reuptake inhibition at higher doses. Because this noradrenergic drive is what leads to hypertension, the risk with venlafaxine is most pronounced at doses ≥225 mg. If sustained increases in blood pressure are noted, options include dose reduction or switching to an alternate antidepressant. (Choice A) Plasma levels of SNRIs are not routinely monitored and would not be indicated in a patient experiencing a positive response. Levels can be used to assess adherence or to identify rapid metabolizers in poor responders. (Choice C) Complete blood counts are not routinely monitored during venlafaxine treatment. SNRIs have been associated with a small increased risk of bleeding due to impaired platelet aggregation, but this is mainly a concern in patients who are already taking anticoagulants. Monitoring for agranulocytosis is required in patients taking clozapine (eg, for schizophrenia). (Choice D) Regular monitoring of lipids is not required in patients taking venlafaxine. Lipids should be routinely monitored in those taking antipsychotics. (Choice E) Venlafaxine is not associated with adverse thyroid effects, and monitoring thyroid function tests during treatment is unnecessary. This patient's initial weight gain was most likely a symptom of her depression (ie, atypical depression frequently presents with increased appetite), and her subsequent weight loss is most likely due to her improvement. Educational objective: The serotonin-norepinephrine reuptake inhibitor venlafaxine is associated with dose-dependent hypertension due to increased norepinephrine reuptake inhibition at higher dose ranges. Blood pressure should be assessed before starting venlafaxine and regularly monitored throughout treatment. References: Serotonin and norepinephrine reuptake inhibitors. (http://www.ncbi.nlm.nih.gov/pubmed/30838456) Accelerated hypertension after venlafaxine usage. (http://www.ncbi.nlm.nih.gov/pubmed/25328745)

A 56-Year-Old Woman Comes to the Office for a Follow-Up