Is headache a side effect of Intuniv (guanfacine)?

Headache as a Side Effect of Intuniv (Guanfacine)

Yes, headache is a recognized side effect of Intuniv (guanfacine), though it is not among the most commonly reported adverse reactions.

Evidence for Headache as a Side Effect

• The FDA drug label for guanfacine lists headache as an adverse reaction that has been reported in clinical trials, though it occurs less frequently than other side effects such as dry mouth, somnolence, and dizziness 1
• In clinical trials, headache was reported in approximately 4% of patients taking guanfacine, compared to similar rates (4%) in patients taking placebo 1
• In a 12-week placebo-controlled combination therapy study, headache was reported in 4% of patients taking guanfacine 1

Common Side Effect Profile of Intuniv (Guanfacine)

• The most common adverse reactions with guanfacine are:

  • Dry mouth (reported in up to 60% of patients) 1
  • Somnolence/sedation (reported in up to 50.7% of patients) 1, 2
  • Dizziness (reported in 6-15% of patients) 1
  • Constipation (reported in 5-15% of patients) 1
  • Fatigue (reported in 9-11% of patients) 1, 2

• In a randomized, double-blind, placebo-controlled study of guanfacine extended release in children with ADHD, headache was the second most commonly reported treatment-emergent adverse event (22.1%), after somnolence 2

Clinical Considerations

• Headache is more likely to occur during the initial titration period and may decrease over time with continued treatment 1
• The National Comprehensive Cancer Network guidelines note that headache is a common adverse event in the general population and can occur with many medications 3
• When headache occurs with guanfacine, it is important to rule out hypertension, particularly if the medication is being discontinued, as rebound hypertension can occur 4
• Most headaches associated with guanfacine are mild to moderate in severity and typically resolve without discontinuation of the medication 1, 5

Management of Headache with Intuniv

• If headache occurs:

  • Assess for other potential causes of headache 3
  • Consider dose adjustment if headache is persistent or severe 1
  • Standard headache treatments (such as acetaminophen or NSAIDs) may be used if not contraindicated 3
  • Monitor for other neurological symptoms that might indicate a more serious condition 1

• In most cases, headache as a side effect does not require discontinuation of guanfacine therapy 1

Important Considerations

• Headache is generally not among the most common reasons for discontinuation of guanfacine therapy 1
• When comparing guanfacine to other medications, such as methyldopa, headache appears to be less common with guanfacine 6
• The incidence of adverse reactions, including headache, tends to decrease over time with continued guanfacine treatment 1

Remember that while headache is a recognized side effect of Intuniv, it is not among the most frequently reported adverse reactions, and it typically does not necessitate discontinuation of therapy unless severe or persistent.