Immediate Management of Bitten Intuniv Tablet in a 5-Year-Old
Contact poison control immediately and monitor the child closely for the next 4-6 hours for signs of excessive sedation, hypotension, and bradycardia, as biting through the extended-release coating causes immediate release of the full 1mg dose rather than the intended gradual 24-hour release. 1
Expected Clinical Effects
The primary concern is that penetrating the extended-release coating converts the tablet into an immediate-release formulation, delivering the entire 1mg dose rapidly rather than over 24 hours. This creates a higher peak plasma concentration than intended. 2
Most Likely Adverse Effects to Monitor
- Somnolence/sedation (occurs in 38.6% even with proper dosing) - this will be the most prominent effect 3
- Hypotension - expect decreases of 1-4 mmHg systolic/diastolic, but potentially more with rapid absorption 4
- Bradycardia - expect heart rate reduction of 1-2 bpm, but monitor for more significant drops 4
- Lethargy and drowsiness - documented as primary overdose symptoms 1
Specific Monitoring Protocol
For the next 4-6 hours, check vital signs every 30-60 minutes:
- Blood pressure (watch for systolic <90 mmHg or drops >10 mmHg from baseline) 4
- Heart rate (watch for <60 bpm or drops >10 bpm from baseline) 4
- Level of consciousness and ability to arouse 1
When to Seek Emergency Care
Go to the emergency department immediately if:
- The child becomes difficult to arouse or excessively lethargic 1
- Heart rate drops below 60 bpm 4
- Systolic blood pressure drops below 90 mmHg or shows significant decline 4
- The child develops irregular heartbeat or chest pain 4
Reassuring Context from Overdose Data
The FDA label documents a case of a 2-year-old weighing 12 kg who ingested up to 4mg (four times this dose) and developed only lethargy, with the lowest recorded systolic pressure of 58 mmHg at 16 hours post-ingestion, requiring no intervention and full recovery within 24 hours. 1 This suggests that a single 1mg dose in a 5-year-old, while concerning, is unlikely to cause severe toxicity.
What NOT to Do
- Do not induce vomiting - the tablet has already been bitten and absorption is occurring 1
- Do not give activated charcoal at home - this is only appropriate in healthcare settings within 2 hours of ingestion 1
- Do not give the next scheduled dose - skip it and resume normal dosing the following day 4
Expected Timeline
Peak effects will occur within 2-4 hours of ingestion, as guanfacine is rapidly absorbed from the gastrointestinal tract. 5 Most symptoms should resolve within 12-24 hours as the drug is eliminated. 5, 6
Prevention for Future Doses
Counsel the family that Intuniv tablets must be swallowed whole and never chewed, crushed, or broken, as this destroys the extended-release mechanism. 2 If the child cannot swallow tablets whole, discuss with the prescriber whether switching to immediate-release guanfacine with adjusted dosing or an alternative formulation is appropriate. 4