Clonidine (Catapres/Kapvay)

What clonidine is

Clonidine is a medication sold under the brand names Catapres and Kapvay. It works as an alpha-2 agonist, which means it calms the nervous-system signals that drive arousal and raise blood pressure. It started as a blood pressure medicine, and that same settling effect is why it is used in mental health. It is not a stimulant and not a controlled substance. It comes as tablets, an extended-release tablet, and a skin patch.

What it treats

In mental health, your clinician might suggest clonidine for:

• Attention-deficit/hyperactivity disorder (ADHD)

Clonidine is also approved for high blood pressure. Beyond those approved uses, it is used off-label, when a clinician judges it a reasonable fit, to help with sleep, anxiety, the on-guard, keyed-up feeling that can come with PTSD, and tics. Off-label use is common and legal when the evidence and a clinician’s judgment support it. Whether it is a good fit depends on several factors, including your blood pressure, your history, and your other medications. As with everything in psychiatry, that is decided case by case.

How it works

Honestly, no one knows with complete certainty how clonidine produces its benefit. What robust research supports is that it calms an overactive part of the nervous system, which can ease a keyed-up, on-guard state and lower blood pressure. The biology is only part of the picture: how much a medication helps, and how it feels, is individual. Two people on the same medication can have very different experiences.

How to take it

There is no single right way to take clonidine; it depends on you and your clinician. The plan you and your clinician make together is the one to follow, not a number you read online. A few points matter here:

• Take it the way you and your clinician agreed, and do not increase the amount on your own.
• Do not stop it suddenly. Stopping abruptly can cause a sharp rebound in blood pressure, so when the time comes your clinician can lower it gradually in a way that is much safer.
• Because it can make you drowsy or lightheaded, be careful with driving or standing up quickly until you know how it affects you.
• If you miss a dose, ask your clinician or pharmacist what to do rather than doubling up.
• If you use the patch, follow the instructions for where and how often to change it, and tell your clinician about any skin reaction where it sits.

What to expect

This varies from person to person. Drowsiness is common in the first days and often eases as your body settles. How much it helps, and how soon, depends on what you are using it for and on you. The right plan may change over time, and that is something you and your clinician revisit together. If it does not turn out to be the right fit, that is useful information, not a dead end, and there are other options. As always, this is case by case.

Side effects

Not everyone gets side effects, and many that do happen ease as your body settles. The lists below are possibilities, not certainties.

Possible more common side effects:

• Drowsiness or sleepiness
• Dry mouth
• Dizziness or lightheadedness, especially when standing up
• Lower blood pressure
• Constipation
• Headache or feeling irritable

If any of these stick around or bother you, send a non-urgent message through the patient portal or bring it up at your next visit; often a small change helps.

Less common, but concerning side effects that could require emergency care:

• Fainting, a very slow heartbeat, or severe dizziness
• A sharp rise in blood pressure if the medicine is stopped suddenly, with severe headache, a racing heart, or anxiety
• For the patch, a severe or blistering skin reaction
• New or worsening low mood or changes in behavior
• Signs of an allergic reaction: rash, hives, or swelling of the face, lips, or throat
• Any new or worsening thoughts of harming yourself

For any of these, use the help options at the top of this page: call 911 or go to the nearest emergency department for a medical emergency or severe reaction, or call or text 988 for a mental health crisis.

When to reach out, and where

For routine questions, side effects that can wait, or how things are going, send your clinician a message through the patient portal. These are part of your ongoing care and are answered in the normal course of a few business days, so they are best for things that are not urgent.

If something feels urgent, you do not need to wait for a reply. The help options at the top of this page are the fastest way to get care: 911 or the nearest emergency department for a medical emergency or severe reaction, or 988 any time for a mental health crisis or thoughts of self-harm.

Questions to ask your clinician

• What are you hoping clonidine will help with in my case?
• How and when will we know if it is working?
• What should I watch for with my blood pressure?
• What should I do about drowsiness or dizziness if they come up?
• What is the plan if this one turns out not to be the right fit?
• How will we handle stopping it, if and when we get there?