PsychoPharm Quiz: SNRIs (Serotonin–norepinephrine reuptake inhibitors)

Check the WRONG statement regarding SNRIs?

(a) Potency order for Norephinephrine reuptake inhibition: Duloxetine > Desvenlafaxine > Venlafaxine.
(b) SNRIs may have greater propensity to cause GI side effects compared to SSRIs.
(c) Emergent discontinuation syndrome is severe with Duloxetine compared to Venlafaxine.
(d) Both Venlafaxine and Duloxetine are category C for pregnant patient.

Admin wrote:

PsychoPharm Quiz: SNRIs (Serotonin–norepinephrine reuptake inhibitors)

Check the WRONG statement regarding SNRIs?

(a) Potency order for Norephinephrine reuptake inhibition: Duloxetine > Desvenlafaxine > Venlafaxine.
(b) SNRIs may have greater propensity to cause GI side effects compared to SSRIs.
(c) Emergent discontinuation syndrome is severe with Duloxetine compared to Venlafaxine.
(d) Both Venlafaxine and Duloxetine are category C for pregnant patient.

Ans: C is Wrong.

* Duloxetine is a potent 5-HT and norepinephrine reuptake inhibitor, while Desvenlafaxine is a stronger inhibitor of NET than is Venlafaxine but a less potent inhibitor of NET than is Duloxetine.

* GI side effects are common with the SNRIs. In fact, the SNRIs may have a somewhat greater propensity for causing nausea than do some of the SSRIs. As with the SSRIs, adaptation to this side effect occurs rapidly, in the first 2–3 weeks of therapy.

* The relatively short half-life and low protein binding of venlafaxine, desvenlafaxine, and milnacipran may predispose patients to an increased risk of discontinuation symptoms when the drug is stopped suddenly.
Duloxetine's longer half-life and higher protein binding may be associated with a lower frequency of discontinuation symptoms compared with venlafaxine. Duloxetine may be safely tapered in most patients by decreasing the total dose by 30 mg per week.

* Both Venlafaxine and Duloxetine are category C for pregnant patient.