Clonidine vs Guanfacine: Key Differences and What Works Best

When it comes to managing high blood pressure or ADHD, clonidine, a central alpha-2 adrenergic agonist used to lower blood pressure and reduce ADHD symptoms. Also known as Catapres, it works by calming down overactive nerve signals in the brain and blood vessels. guanfacine, another alpha-2 agonist often prescribed for ADHD and sometimes hypertension. Also known as Intuniv, it acts more selectively on the brain’s prefrontal cortex, helping with focus and impulse control. Both are classified as alpha-2 agonists, a class of drugs that reduce sympathetic nervous system activity, but they’re not interchangeable. Many people assume they’re the same because they treat similar conditions—but that’s where the similarity ends.

Clonidine hits harder and faster. It’s often used when you need quick blood pressure control, like in a hospital setting or for sudden spikes. But it can cause drowsiness, dry mouth, and sudden drops in blood pressure if you stand up too fast. Guanfacine, on the other hand, is slower to kick in but lasts longer. It’s usually taken once a day and tends to be gentler on the body. For kids with ADHD, guanfacine is often preferred because it causes less sedation and doesn’t spike blood pressure as sharply when doses are missed. Clonidine patches are also available for steady, long-term use—useful if you forget pills—but they can irritate the skin. Neither drug is a first-line ADHD treatment for everyone, but they’re valuable when stimulants don’t work or cause too many side effects.

Both drugs can interact with other medications, especially those that lower blood pressure or affect the heart. If you’re on beta-blockers, antidepressants, or sleep aids, your doctor needs to know. Neither is safe to stop cold turkey—sudden withdrawal can cause dangerous spikes in blood pressure or anxiety. That’s why most people start low and go slow. The choice between clonidine and guanfacine often comes down to your body’s response, your daily routine, and whether you’re treating high blood pressure, ADHD, or both. You might need to try one, then the other, to see which fits your life better.

Below, you’ll find real-world comparisons, patient experiences, and clinical insights from posts that break down exactly how these two drugs stack up—side effects, dosing, long-term use, and what to watch for when switching between them.