What is the best approach to treat Attention Deficit Hyperactivity Disorder (ADHD) in patients with Postural Orthostatic Tachycardia Syndrome (POTS)?

Treatment of ADHD in Patients with POTS

For patients with ADHD and comorbid POTS, non-stimulant medications should be used as first-line therapy, with guanfacine (Intuniv) being the preferred option at an initial dose of 0.1 mg/kg once daily. 1

First-Line Treatment Options

Non-Stimulant Medications

1. Guanfacine (Intuniv)

   • Starting dose: 0.1 mg/kg once daily 1
   • Mechanism: Alpha-2 adrenergic receptor agonist that enhances noradrenergic neurotransmission in the prefrontal cortex
   • Advantages: Lower risk of exacerbating orthostatic symptoms and tachycardia compared to stimulants
   • Particularly beneficial for POTS patients due to minimal cardiovascular side effects

2. Atomoxetine (Strattera)

   • Use with caution in POTS patients
   • Research shows atomoxetine can worsen POTS symptoms:
     • Significantly increases standing heart rate (121±17 bpm vs 105±15 bpm with placebo) 2
     • Worsens symptom scores in POTS patients 2
   • If considered, start at lower doses (0.5 mg/kg/day) and monitor closely 1

3. Bupropion

   • Starting dose: 100-150 mg daily (sustained-release) or 37.5 mg every morning 1
   • Target dose: 150 mg twice daily 1
   • Monitor for potential cardiovascular effects

Treatment Algorithm

1. Initial Assessment

   • Evaluate severity of both ADHD and POTS symptoms
   • Assess cardiovascular parameters (baseline heart rate, blood pressure)
   • Screen for other comorbidities (anxiety, depression)

2. Treatment Selection

   • Start with guanfacine as first-line therapy
   • If inadequate response after 4-6 weeks:
     • Consider dose adjustment
     • Consider adding behavioral interventions
     • Consider atomoxetine at low doses with careful monitoring

3. Monitoring

   • Follow-up within 2-4 weeks after medication initiation 1
   • Regular assessment of:
     • ADHD symptoms
     • POTS symptoms (orthostatic intolerance, tachycardia)
     • Blood pressure and heart rate
     • Side effects

Special Considerations

Stimulant Medications

• Generally avoided as first-line in POTS patients due to potential to exacerbate tachycardia
• However, methylphenidate may be considered in refractory cases:
  • One study showed that methylphenidate provided symptomatic relief in 77% of refractory POTS patients 3
  • 9 out of 12 patients with recurrent syncope reported no syncope after 6 months of treatment 3
  • Consider as a third-line option when non-stimulants fail

Combined Approaches

• Combine medication with behavioral interventions for optimal outcomes 1
• Consider orthostatic rehabilitation for POTS patients who develop orthostatic intolerance 4
• Regular follow-up is essential to monitor both ADHD and POTS symptoms

Cautions

• Avoid combining atomoxetine with monoamine oxidase inhibitors due to risk of serotonin syndrome 1
• Be cautious with medications that can reduce blood pressure, as they may exacerbate orthostatic symptoms 4
• Monitor for development of tolerance to medications

Adjunctive Therapies

• Structured exercise program may help improve POTS symptoms 5
• Cognitive Behavioral Therapy (CBT) for older adolescents and adults with ADHD 1
• Parent training in behavior management for children and adolescents 1

Remember that hyperadrenergic POTS patients (those with elevated norepinephrine levels upon standing) may be particularly difficult to treat 6 and may require more careful medication selection and monitoring.