Can Strattera and Plaquenil Be Used Together?
Yes, a patient can be prescribed Strattera (atomoxetine) together with Plaquenil (hydroxychloroquine) - there are no documented pharmacokinetic interactions or contraindications between these medications. However, both drugs require cardiovascular monitoring, which becomes particularly important when used in combination.
Key Safety Considerations
Cardiovascular Monitoring is Essential
Both medications affect cardiovascular parameters, making baseline and ongoing monitoring critical:
Atomoxetine can increase heart rate and blood pressure in 5-15% of patients 1. The FDA label notes small increases in QTc interval with increased atomoxetine concentration, though clinically significant QTc prolongation was not observed in formal studies 2.
Hydroxychloroquine itself has minimal direct cardiovascular effects at therapeutic doses, but the combination requires vigilance.
Before initiating this combination:
- Obtain personal and family cardiac history (sudden death, Wolff-Parkinson-White syndrome, hypertrophic cardiomyopathy, long QT syndrome)
- Perform baseline ECG if any cardiac risk factors are present 1
- Monitor blood pressure and heart rate at baseline and regularly during treatment
No Metabolic Drug Interactions
The pharmacokinetic profiles make drug-drug interactions unlikely:
Atomoxetine is metabolized primarily via CYP2D6 2. Research confirms atomoxetine does not inhibit or induce CYP2D6, CYP1A2, CYP2C9, or CYP3A pathways at therapeutic doses 3.
Hydroxychloroquine is cleared primarily by the kidney and does not significantly interact with the CYP450 system 4.
These distinct metabolic pathways mean neither drug will alter the other's plasma concentrations.
Dosing Considerations
Atomoxetine Dosing
- Standard dosing: ≤1.4 mg/kg/day (optimal efficacy plateau) 5
- Maximum: typically 100 mg/day or 1.4 mg/kg/day, whichever is less
- Monitor for increased blood pressure and heart rate 1
Hydroxychloroquine Dosing
- Critical: Keep ≤5.0 mg/kg/day based on real weight to minimize retinopathy risk 4, 6
- For severely obese patients, keep under 400 mg/day regardless of weight
- Requires baseline ophthalmologic examination and annual screening with OCT and fundus autofluorescence 6
Clinical Monitoring Algorithm
At initiation:
- Cardiac history and baseline vital signs
- Baseline ECG if cardiac risk factors present
- Baseline ophthalmologic exam for hydroxychloroquine (OCT, fundus autofluorescence) 6
Ongoing monitoring:
- Blood pressure and heart rate at each visit during atomoxetine titration
- Annual ophthalmologic screening for hydroxychloroquine retinopathy 6
- Monitor for atomoxetine adverse effects: somnolence, GI symptoms, decreased appetite 1
Common Pitfalls to Avoid
- Don't overdose hydroxychloroquine: Doses >5.0 mg/kg dramatically increase retinopathy risk, with some reports showing 25-40% incidence at extreme doses (800-1000 mg/day) within 1-2 years 4
- Don't ignore renal function: Hydroxychloroquine is renally cleared; renal disease increases drug levels and toxicity risk 4
- Don't skip cardiac screening: Both medications have cardiovascular effects that are generally mild but require baseline assessment 1
Special Populations
Patients with renal disease require particular caution, as hydroxychloroquine clearance is reduced, effectively increasing circulating drug levels and retinopathy risk 4. Consider dose adjustment and more frequent monitoring.
CYP2D6 poor metabolizers (7% of Caucasians, 2% of African Americans) will have 10-fold higher atomoxetine exposure 2, but this doesn't affect the safety of combining with hydroxychloroquine - it simply requires standard atomoxetine dose reduction.