Which affects blood pressure less, Guanfacine, Wellbutrin (Bupropion) or Strattera (Atomoxetine)?

Blood Pressure Effects: Guanfacine vs Wellbutrin vs Strattera

Guanfacine affects blood pressure the least among these three medications, as it actually lowers blood pressure through its alpha-2 agonist mechanism, while both Wellbutrin (bupropion) and Strattera (atomoxetine) can increase blood pressure and heart rate. 1

Mechanism and Blood Pressure Impact

Guanfacine: Blood Pressure Lowering

• Guanfacine is an alpha-2 adrenergic receptor agonist that reduces peripheral vascular resistance and consequently lowers blood pressure through its action in the brain stem 1
• This medication was originally developed and is still used as an antihypertensive agent, with documented blood pressure reductions of approximately 16% in clinical trials 2
• The blood pressure lowering effect is dose-dependent, with optimal antihypertensive response at lower doses (2-6 mg/day), while doses exceeding 6 mg/day may show deteriorating antihypertensive response 3
• Guanfacine is specifically approved as adjunctive therapy to stimulants in ADHD treatment to decrease adverse cardiovascular effects, including elevated blood pressure and heart rate 1

Strattera (Atomoxetine): Cardiovascular Warnings

• Atomoxetine carries warnings for preexisting cardiovascular diseases and significant cardiac abnormalities, indicating it can adversely affect blood pressure 1
• While atomoxetine has "similar cardiovascular effects to stimulants," this means it can increase blood pressure and heart rate, though the evidence suggests these effects are relatively modest 1
• The medication requires cardiovascular monitoring, particularly in patients with preexisting cardiac conditions 1

Wellbutrin (Bupropion): Blood Pressure Elevation

• While not extensively covered in the provided ADHD-focused guidelines, bupropion is known to increase blood pressure and heart rate through its noradrenergic and dopaminergic activity
• This medication is generally avoided in patients with uncontrolled hypertension in clinical practice

Clinical Algorithm for Selection

If blood pressure is a primary concern:

1. First choice: Guanfacine - actively lowers blood pressure while treating the underlying condition 1, 4

   • Particularly beneficial if patient has comorbid hypertension
   • Can be dosed once daily at bedtime to minimize sedation 1
   • Lower risk of withdrawal syndrome compared to clonidine 4, 2

2. Second choice: Strattera (atomoxetine) - has modest cardiovascular effects but requires monitoring 1

   • May be acceptable in patients with normal baseline blood pressure
   • Requires 6-12 weeks to see full therapeutic effect 1

3. Avoid: Wellbutrin (bupropion) - can elevate blood pressure

   • Should not be used in patients with uncontrolled hypertension or significant cardiovascular concerns

Important Caveats

Guanfacine Considerations

• Sedation and fatigue are common adverse effects, particularly at higher doses, though less pronounced than with clonidine 1
• Evening dosing is generally preferable to minimize daytime sedation 1
• While withdrawal syndrome is possible with abrupt discontinuation, symptoms are generally mild and occur less frequently than with clonidine 4, 2, 5
• The medication should still be tapered gradually when discontinuing 6
• Therapeutic effects for ADHD take 2-4 weeks to manifest, unlike stimulants which work immediately 1

Monitoring Requirements

• All three medications require baseline and periodic blood pressure monitoring
• For guanfacine, monitor for excessive blood pressure lowering, particularly in patients not hypertensive at baseline 3
• For atomoxetine and bupropion, monitor for blood pressure elevation 1

The choice is clear: guanfacine is the only medication among these three that lowers rather than raises blood pressure, making it objectively the best option when cardiovascular effects are the primary concern. 1, 4, 2