Yes, Guanfacine and Intuniv Are the Same Medication
Intuniv is simply the brand name for guanfacine extended-release (ER), while guanfacine is the generic drug name. They contain the same active pharmaceutical ingredient—guanfacine hydrochloride—but differ in their formulation 1.
Key Distinction: Formulation Matters
The critical difference lies in the extended-release versus immediate-release formulation, not in the active drug itself:
- Intuniv (guanfacine ER): Extended-release formulation designed for once-daily dosing, FDA-approved specifically for ADHD treatment 1
- Immediate-release guanfacine: Shorter-acting formulation, traditionally used for hypertension
These formulations are NOT interchangeable on a milligram-for-milligram basis 1. The extended-release formulation (Intuniv) has significantly different pharmacokinetics:
- 60% lower peak concentration (Cmax)
- 43% lower overall exposure (AUC)
- Relative bioavailability of only 58% compared to immediate-release guanfacine
- Delayed time to peak (approximately 5-6 hours vs. 3 hours) 1
Clinical Implications
When prescribing or discussing these medications:
Do not substitute immediate-release guanfacine for Intuniv on a 1:1 mg basis—this will result in inadequate dosing 1
If switching from immediate-release to Intuniv: Discontinue the immediate-release formulation and titrate Intuniv according to recommended dosing (starting at 1 mg/day, adjusting by no more than 1 mg/week) 1
Dosing range: Intuniv is dosed 1-4 mg once daily for ADHD, with weight-adjusted dosing (0.05-0.12 mg/kg) providing optimal balance of efficacy and safety 1
Administration: Intuniv tablets must be swallowed whole—crushing, chewing, or breaking tablets increases the rate of guanfacine release and alters pharmacokinetics 1
Regulatory Status
Guanfacine extended-release (Intuniv) is approved as an extended-release formulation for ADHD treatment as monotherapy or adjunctive therapy to stimulants 2. In Europe, it's only approved when stimulants are not suitable, not tolerated, or ineffective 2. The immediate-release formulation is not FDA-approved for ADHD treatment.
Bottom line: When patients or providers refer to "guanfacine" in the context of ADHD treatment, they typically mean the extended-release formulation (Intuniv), but clarification is essential to ensure proper dosing and expectations.