Neither hydroxyzine nor propranolol is optimal for severe generalized anxiety disorder—use an SSRI or SNRI instead
For severe generalized anxiety disorder with normal renal function, hydroxyzine is marginally superior to propranolol, but both are suboptimal choices compared to first-line SSRIs or SNRIs.
Why This Recommendation
Guideline Evidence Against Propranolol
The Canadian Clinical Practice Guideline explicitly deprecates propranolol for anxiety disorders based on negative evidence 1. This is a strong statement against its routine use in generalized anxiety disorder.
Research Evidence Comparison
Hydroxyzine:
- Demonstrated efficacy in a 3-month double-blind trial for GAD with HAM-A score reduction of -12.16 vs -9.64 for placebo (p=0.019) 2
- Showed comparable efficacy to bromazepam (a benzodiazepine) 2
- Well-tolerated except for drowsiness 2
Propranolol:
- A 2016 systematic review and meta-analysis found insufficient evidence to support routine use in any anxiety disorder 3
- Limited to performance anxiety and specific social phobias, not generalized anxiety 4
- Works primarily on somatic symptoms of anxiety rather than core psychological symptoms 4
The Critical Distinction
Propranolol blocks peripheral beta-adrenergic receptors, reducing physical manifestations of anxiety (tremor, tachycardia, sweating) but does not address the core psychological symptoms of GAD 4, 5. This makes it useful for situational performance anxiety but inadequate for chronic, severe GAD.
Hydroxyzine, as an H1-antihistamine antagonist, has demonstrated actual anxiolytic effects on both psychological and somatic symptoms in controlled trials 2, 6.
Treatment Algorithm for This Patient
Step 1: Start an SSRI (escitalopram or sertraline) or SNRI (venlafaxine) as first-line therapy 1, 7
Step 2: If SSRIs/SNRIs are contraindicated or refused:
- Consider hydroxyzine 50 mg/day as a reasonable alternative 2
- Avoid propranolol for generalized anxiety 1, 3
Step 3: If immediate symptom relief needed while titrating SSRI/SNRI:
Important Caveats
Renal Function Considerations
While this patient has normal renal function (normal creatinine and eGFR despite BUN 25 mg/dL), propranolol levels increase 2-3 fold in renal failure and the drug is not dialyzable 9. The elevated BUN warrants monitoring, though current renal function is adequate for either medication.
Drug Interactions
Propranolol has extensive CYP450 interactions (CYP2D6, 1A2, 2C19) that can lead to significant toxicity 9. Common interactions include:
- SSRIs (fluoxetine, paroxetine, fluvoxamine) increase propranolol levels
- Calcium channel blockers risk severe bradycardia and heart failure 9
- Multiple cardiovascular medications have additive effects 9
Hydroxyzine has a cleaner interaction profile 2.
Duration of Treatment
GAD is a chronic illness requiring long-term treatment 10. Hydroxyzine has demonstrated 3-month efficacy 2, while propranolol's efficacy beyond 4 weeks remains unproven 4.
Why Not Propranolol for GAD?
The evidence is clear: propranolol works for performance anxiety and specific social phobias (public speaking, musical performance) at doses of 20-40 mg taken before the anxiety-provoking event 4, 5. It does not work for the persistent, pervasive worry and tension that characterizes severe GAD 3, 4.
The 2016 meta-analysis found no statistically significant benefit of propranolol over placebo for generalized anxiety 3, and international guidelines actively recommend against its use 1.
Bottom Line
If forced to choose between these two medications for severe GAD: use hydroxyzine 50 mg/day 2. However, the correct clinical decision is to prescribe an SSRI (escitalopram or sertraline) or SNRI (venlafaxine) as first-line therapy 1, 7, potentially using hydroxyzine as bridge therapy during the 4-6 week SSRI/SNRI titration period.