Guanfacine Immediate-Release Tablets Can Be Crushed
Guanfacine immediate-release (IR) tablets can be safely crushed for patients with swallowing difficulties, as the IR formulation lacks special release mechanisms that would be disrupted by crushing. This is fundamentally different from guanfacine extended-release (ER) tablets, which should never be crushed.
Key Distinction Between IR and ER Formulations
Immediate-release guanfacine tablets are simple, uncoated formulations without sustained-release properties, making them suitable for crushing when necessary 1, 2.
Extended-release guanfacine tablets must never be crushed because destroying the controlled-release matrix causes immediate release of the entire dose, resulting in dangerous overdose with excessive hypotension, bradycardia, and sedation 3.
Practical Guidance for Crushing IR Guanfacine
When crushing is necessary, use a mortar and pestle to create a fine powder, suspend immediately in plain water at room temperature, and administer within 2 hours 4.
The person crushing the tablets should take precautions to avoid inhaling drug particles, as exposure to pharmaceutical dust can cause allergic reactions or other adverse effects 5.
Crushing IR guanfacine does not alter its pharmacokinetic profile or therapeutic efficacy, as demonstrated by studies showing equivalent plasma levels between crushed and whole IR tablets 1.
Clinical Context and Monitoring
Guanfacine causes modest decreases in blood pressure (1-4 mmHg) and heart rate (1-2 bpm), requiring baseline and periodic cardiovascular monitoring regardless of whether tablets are crushed or swallowed whole 3.
Never abruptly discontinue guanfacine—taper by 1 mg every 3-7 days to avoid rebound hypertension, a risk that applies equally to crushed and whole tablets 3, 2.
Common Pitfall to Avoid
- Do not confuse IR and ER formulations—only IR tablets are crushable. The ER formulation (Intuniv) requires intact tablet administration to maintain its 24-hour duration of action 3.