What is the recommended starting dose of Strattera (atomoxetine) in a patient already taking Effexor (venlafaxine) and Wellbutrin (bupropion)?

Starting Dose for Strattera When Already on Effexor and Wellbutrin

Start atomoxetine at the standard dose of 40 mg once daily, regardless of concurrent use of venlafaxine and bupropion. 1

Initial Dosing Strategy

• Begin atomoxetine at 40 mg once daily as the standard starting dose, which does not require adjustment based on concurrent antidepressant therapy 1
• This approach allows assessment of tolerability in the context of existing medications while maintaining safety 1

Titration Schedule

• Increase to 60 mg daily after 7-14 days if the initial dose is well tolerated 1, 2
• Further titration to 80 mg may be considered if clinically indicated and tolerated 1, 2
• Maximum dose is 100 mg/day or 1.4 mg/kg/day (whichever is less) 1, 2
• Do not rush the titration process—allow adequate time between dose increases to assess tolerability 1

Critical Drug Interaction and Safety Monitoring

Blood Pressure Monitoring

• Both venlafaxine and atomoxetine can increase blood pressure, requiring baseline and regular monitoring during titration 1
• Check blood pressure at each dose adjustment and regularly thereafter 1

Activation and Agitation

• Monitor for increased agitation, as bupropion has activating properties that may be additive with atomoxetine 1
• Watch for anxiety or mood changes during the initiation period 1

Seizure Risk Considerations

• Bupropion lowers the seizure threshold and requires careful attention to dosing limits 1, 2
• Maximum safe dose of bupropion is 400 mg/day for SR formulation to minimize seizure risk 1, 3
• Ensure bupropion doses are not taken late in the day to minimize insomnia 1

Absolute Contraindications to This Combination

• Active seizure disorder or history of seizures (due to bupropion) 1, 2
• Current MAOI use or within 14 days of MAOI discontinuation 1, 2
• Eating disorders (anorexia nervosa or bulimia) if on bupropion 1, 2
• Abrupt discontinuation of alcohol or benzodiazepines (increased seizure risk with bupropion) 2

Clinical Rationale for Standard Dosing

• The combination provides complementary mechanisms of action: atomoxetine (norepinephrine reuptake inhibition), venlafaxine (serotonin and norepinephrine reuptake inhibition), and bupropion (norepinephrine and dopamine reuptake inhibition) 1
• Starting at the standard 40 mg dose allows proper assessment of tolerability without the confounding effects of starting too high 1

Common Pitfalls to Avoid

• Do not start atomoxetine at higher doses despite concurrent medications 1
• Do not exceed maximum doses of any medication in the regimen (atomoxetine 100 mg/day, bupropion SR 400 mg/day) 1
• Do not ignore timing of bupropion doses—second dose should be before 3 PM to minimize insomnia 1, 4
• Do not skip blood pressure monitoring, as both venlafaxine and atomoxetine can cause hypertension 1