Guanfacine Side Effects and Clinical Implications

Adverse Effects and Monitoring

The American Academy of Pediatrics and other guideline societies note that somnolence, headache, and fatigue are common adverse effects of guanfacine, occurring in 5-38.6% of patients 1
Cardiovascular effects, including modest decreases in blood pressure and heart rate, are primary monitoring concerns, with hypotension and bradycardia possible during dose adjustments 1
Behavioral and psychiatric effects, such as irritability, hallucinations, and secondary mania, can occur in vulnerable individuals, particularly children with risk factors for bipolar disorder 1
The American Academy of Child and Adolescent Psychiatry recommends monitoring for behavioral activation, mood changes, or emotional lability during guanfacine dose titration 1

Continuous crying is documented as part of SSRI withdrawal syndrome in newborns exposed during pregnancy, but this is not applicable to pediatric or adult patients taking guanfacine for ADHD or hypertension 2
If a patient reports crying as a new symptom after starting guanfacine, consider alternative explanations, such as underlying mood disorder, unmasking of bipolar disorder, emotional dysregulation, or comorbid anxiety or mood symptoms 1, 2