Moderate
Alprazolam × venlafaxine
Benzodiazepines. Short-to-medium-acting anxiolytics×SNRI (serotonin-norepinephrine reuptake inhibitor)
Mechanism
Additive CNS depression (minimal for venlafaxine, mainly from alprazolam). High-dose venlafaxine (above 150 mg/day) also raises BP.
Symptoms
Sedation, fatigue, slowed reactions, impaired coordination. In older patients: fall and fracture risk. Driving and operating machinery: accident risk.
Management
On starting the combination, begin alprazolam at the minimum dose. For long-term anxiety treatment, prioritise antidepressant monotherapy with CBT and gradual benzodiazepine taper. In arterial hypertension, check BP 2 weeks after starting venlafaxine.