Drowsiness Effects of Buspar (Buspirone) and Pristiq (Desvenlafaxine)
Buspar (buspirone) is unlikely to cause significant drowsiness, while Pristiq (desvenlafaxine) may cause drowsiness in some patients.
Buspirone (Buspar) and Drowsiness
Buspirone has a distinct pharmacological profile that differentiates it from many other anxiolytic medications:
According to the FDA drug label, drowsiness is reported in approximately 10% of patients taking buspirone, which is not significantly different from the 10% reported with placebo 1.
Unlike benzodiazepines which commonly cause sedation, buspirone lacks significant sedative properties. In comparative studies, the incidence of drowsiness with buspirone (9%) was significantly less than with diazepam (32%), clorazepate (26%), lorazepam (58%), and alprazolam (43%) 2.
Some research suggests buspirone may actually have mild stimulant properties rather than sedative effects. A study examining buspirone's effects on sleep found that it increased wake time after sleep onset, suggesting limited usefulness in anxious patients with concomitant sleep difficulties 3.
The most common side effects of buspirone include dizziness (12%), nervousness (5%), headache (6%), and lightheadedness (3%), rather than drowsiness 1, 2.
Desvenlafaxine (Pristiq) and Drowsiness
While we don't have specific evidence about desvenlafaxine in the provided materials, as an SNRI (Serotonin-Norepinephrine Reuptake Inhibitor), it can potentially cause drowsiness in some patients, though this is not typically its most prominent side effect.
Important Considerations for Both Medications
Factors that may increase risk of drowsiness:
- Advanced age
- Hepatic or renal impairment
- Concurrent use of other CNS depressants
- Individual sensitivity
Practical recommendations:
- Take medications at consistent times (either always with or always without food)
- Be cautious when driving or operating machinery until you know how these medications affect you
- Avoid alcohol consumption while taking these medications
- Report persistent or bothersome drowsiness to your healthcare provider
Special precautions:
For buspirone: The FDA label specifically states that patients should be cautioned about operating automobiles or using complex machinery until they are reasonably certain that buspirone treatment does not affect them adversely 1.
For both medications: Avoid concurrent use with alcohol as this may increase CNS depression 1.
Conclusion
While individual responses can vary, buspirone is generally not associated with significant drowsiness compared to placebo, and may even have mild stimulant properties in some individuals. Desvenlafaxine may cause drowsiness in some patients, though this is not typically its most prominent side effect.