Hypertension and orthostatic hypotension with venlafaxine treatment in depressed older adults

BACKGROUND

Venlafaxine, a serotonin-norepinephrine reuptake inhibitor, is often used as first- or second-line therapy for depression in older adults. It can be associated with adverse blood pressure (BP) effects.

METHODS

Adults ⩾60 years of age in a current major depressive episode were treated in a protocolized manner with venlafaxine XR; 429 participants were treated for 8-16 weeks with a daily dose up to 300 mg to achieve remission from depression. Cardiac measures included sitting and standing BP and heart rate.

RESULTS

Of participants who were normotensive at baseline, 6.5% were found to have elevated BP during the study (1.9% <225 mg/day; 9.8% ⩾225 mg/day). There was no significant change in mean BP in the overall sample, or in the subgroup treated with doses ⩾225 mg/day. Additionally, 20.1% of the participants who did not have orthostatic hypotension at baseline were found to have orthostatic hypotension (16.8% <225 mg/day; 22.4% ⩾225 mg/day). Participants with new-onset orthostatic hypotension were significantly more likely to fall than the other participants.

CONCLUSION

A large proportion of older adults treated with venlafaxine experience orthostatic hypotension, putting them at risk for falls. A smaller proportion experience elevated BP. Older patients prescribed venlafaxine, particularly at high doses, should be advised and counseled about these adverse effects.

Xin-deficient mice display myopathy, impaired contractility, attenuated muscle repair and altered satellite cell functionality

AIM

Xin is an F-actin-binding protein expressed during development of cardiac and skeletal muscle. We used Xin-/- mice to determine the impact of Xin deficiency on different aspects of skeletal muscle health, including functionality and regeneration.

METHODS

Xin-/- skeletal muscles and their satellite cell (SC) population were investigated for the presence of myopathic changes by a series of histological and immunofluorescent stains on resting uninjured muscles. To further understand the effect of Xin loss on muscle health and its SCs, we studied SCs responses following cardiotoxin-induced muscle injury. Functional data were determined using in situ muscle stimulation protocol.

RESULTS

Compared to age-matched wild-type (WT), Xin-/- muscles exhibited generalized myopathy and increased fatigability with a significantly decreased force recovery post-fatiguing contractions. Muscle regeneration was attenuated in Xin-/- mice. This impaired regeneration prompted an investigation into SC content and functionality. Although SC content was not different, significantly more activated SCs were present in Xin-/- vs. WT muscles. Primary Xin-/- myoblasts displayed significant reductions (approx. 50%) in proliferative capacity vs. WT; a finding corroborated by significantly decreased MyoD-positive nuclei in 3 days post-injury Xin-/- muscle vs. WT. As more activated SCs did not translate to more proliferating myoblasts, we investigated whether Xin-/- SCs displayed an exaggerated loss by apoptosis. More apoptotic SCs (TUNEL+/Pax7+) were present in Xin-/- muscle vs. WT. Furthermore, more Xin-/- myoblasts were expressing nuclear caspase-3 compared to WT at 3 days post-injury.

CONCLUSION

Xin deficiency leads to a myopathic condition characterized by increased muscle fatigability, impaired regeneration and SC dysfunction.