How do I choose the appropriate selective serotonin reuptake inhibitor (SSRI) for a newly depressed/anxious patient? What are the differences in side effects and responses to the available SSRIs? I know they behave differently from the clinical responses I see in my patients, but I cannot find a guideline for differentiating among these commonly used drugs. — Tracy Poepping, NP, Lone Tree, Colo.

To my knowledge, there are no studies comparing one SSRI to another, so choosing the most appropriate medication for the new diagnosis of depression and/or anxiety is more of an art than a science. Clinicians can and should read the drug information for each specific medication being prescribed. While a comparison of studies used for FDA approval can provide some guidance, this indirect comparison ranks low on the evidence-based pyramid.

Newer SSRIs target the selective serotonin receptors more specifically than the older formulations and thus have fewer unintended consequences. If I have an established patient that I have screened negatively for a mood disorder (i.e., Bipolar I or II), I often choose either citalopram (Celexa) or sertraline (Zoloft) as an initial agent.

Citalopram is useful because (1) it is on the formulary at large retail pharmacies for $4/month or $10/three months; (2) dosing is easy — one week of 10 mg daily followed by 20 mg daily; (3) the side effect profile is very neutral (minimal weight gain and fewer sexual side effects than some of the older SSRIs); and (4) it is nonsedating.

The benefits of sertraline are (1) it is generic and therefore the lowest copay on insurance; (2) its many dosing increments allow clinicians to fine-tune the dose for more sensitive patients; (3) a side effect of the medication is that it calms abdominal symptoms, and irritable bowel syndrome is common in the anxious/depressed patient.

It is important to screen for a mood disorder because bipolar patients often present to primary care during the depressed phase. Treatment with an SSRI can trigger a manic phase and should be avoided.

SSRIs take full effect after four weeks. If a patient has marked anxiety, consider a short course of a benzodiazepine (i.e., lorazepam [Ativan] or alprazolam [Xanax]) for prompt initial relief. For follow-up, speak with the patient via telephone in one week to evaluate initial response, and schedule an office visit in one month to assess effectiveness of the initial dose. Finally, increase the dose of the initial medication until complete or near-complete resolution of symptoms occurs. — Rebecca H. Bryan, APRN, CNP (161-6)

These are letters from practitioners around the country who want to share their clinical problems and successes, observations and pearls with their colleagues. We invite you to participate. If you have a question, submit it here.