ADHD Nonstimulants: Atomoxetine (SNRIs)

00:01 Hi, I'm Doctor Rhonda Lawes, and in this discussion we're going to look at the treatment of ADHD with medications that are not stimulants.

00:09 Now this part of it we're going to look at selective norepinephrine reuptake inhibitors or snris for a much shorter version of their name.

00:18 Now these are non stimulants.

00:19 There's three main classes that you can use to treat ADHD that are not considered stimulants. You can use Snris.

00:26 And I've got examples for you up there.

00:28 You can use alpha two adrenergic agonists and you can use antidepressants.

00:34 Now these are used off label for ADHD.

00:37 But remember there are FDA approved to treat comorbid anxiety or depression.

00:43 Now you're going to use these in this case in our discussion we're talking about how to use these medications in the treatment of ADHD.

00:50 So what type of client would you use these for.

00:54 Well you're going to prescribe these medications for ADHD.

00:57 If the client has had poor response to other treatment options or they just couldn't tolerate the adverse effects of the stimulant or other medications.

01:06 So three main classes snris, alpha two adrenergic agonists and antidepressants.

01:13 Okay. So let's get into that.

01:15 And this one we're going to look at the snris.

01:19 So one example we have up there is the atomoxetine.

01:22 Now technically it's not an snri but it acts as a norepinephrine reuptake inhibitor.

01:29 So you know what that means. You're going to end up with extra norepinephrine in that synaptic cleft.

01:34 Now it's still a classification as a non stimulant and its focus is on norepinephrine.

01:41 So for the snris we're going to use an example atomoxetine.

01:47 Let's break down the mechanism of action of Atomoxetine.

01:50 Now this image will help you just kind of solidify this in your mind of how this drug works. You see that we have the two neurons, presynaptic and postsynaptic.

02:00 And the little circles there are going to represent norepinephrine.

02:04 Now this medication this atomoxetine, is a highly selective norepinephrine reuptake inhibitor. Okay.

02:12 So you see we've got that marked for you right there in the image.

02:16 Now when you have less of the norepinephrine being taken back into the presynaptic neuron, you end up with more norepinephrine staying in the synaptic cleft.

02:27 This is how there's more norepinephrine available to the client's brain to be used.

02:32 Now this will target specific regions.

02:34 This medication, particularly the prefrontal cortex, which we know is critical for the patient being able to pay attention, executive function and decision making.

02:44 Now it has little or no affinity for the other neurotransmitters, receptors or transporters. So that's what's unique about the Atomoxetine.

02:53 It doesn't really like or hang out or are attracted to the other neurotransmitter receptors or transporters.

03:00 Now what happens to the patient? How do they feel? Well, what we're after is it improves their improves their concentration and their attention.

03:07 Remember, they have more norepinephrine available to them in the synaptic cleft, that it has little to no effect on the motor or the reward processes.

03:16 So this medication is going to focus specifically on improving concentration and attention. Now there's a lot of adverse effects with this medication as there are with most medications.

03:27 But usually these are mostly related to its effect on the noradrenergic activity in the body. So those common signs that you're going to see sound a little bit similar to some of the things you saw for stimulants, you're going to see an increased blood pressure. They may be at risk for hypertension.

03:43 They have an elevated heart rate maybe up to tachycardia.

03:47 They may also have some weight loss and abdominal pain.

03:49 Their appetite may be suppressed and it may also lead to nausea and vomiting.

03:55 Well, your patient needs to be aware that these symptoms may occur so that you can keep in constant conversation with them.

04:01 You can help them monitor or modulate those adverse effects.

04:05 Now there are some rare ones and we definitely wanted to share these with you.

04:09 But keep in mind these are rare.

04:11 Now you know that's a common effect, that it might have a fast heart rate and elevated blood pressure. But you can also have some severe cardiovascular events, including sudden death. So the next one is a priapism.

04:24 That's a very painful and extended erection.

04:27 Again that's rare.

04:28 That might have suicidal thinking.

04:30 And that's on the boxed warning for this medication.

04:33 The patient may also experience a new onset of psychotic or manic symptoms, for example hallucinations, delusional thinking or even mania.

04:43 So the patient needs to be aware, as do the important people around them in their inner circle, to be aware that the patient might be experiencing this and encourage the patient to be very open about what they're experiencing.

04:55 So you can address this.

04:57 And lastly, there could possibly be an idiosyncratic severe liver injury.

05:02 So you want to monitor for that on a routine basis.

05:06 Now because Atomoxetine we talked about the hypertension.

05:10 We know that this is a difficult medication for a patient with glaucoma.

05:14 Anything that raises your blood pressure can also raise the pressures in your eye.

05:17 So we would want to avoid that if the client has had a current or past history of pheochromocytoma. This would be a contraindication if the patient has severe cardiovascular or cerebral vascular disorders.

05:30 That's an obvious contraindication, right? Because this could cause the tachycardia and the extra stress on the cardiovascular system. Elevated blood pressure.

05:39 This would be a contraindication.

05:41 Now if you know that they're hypersensitive to atomoxetine or any of its components, of course you wouldn't prescribe the medication.

05:48 And finally, as with other medications, you don't want to give this medication with MAOIs. You want it to be at least a 14 day window where the patient has not had any maoi before they would start taking a medication like atomoxetine.

06:03 You can prescribe atomoxetine for ADHD in patients who are at least six years of age or older. Now you're going to consider this medication as an alternative to stimulants.

06:13 If the patient or someone in their household has a substance use disorder.

06:17 So you may have discovered that disorder, or it may be a known thing that you found in their assessment. This is another option that you can use if the patient has tics.

06:26 This would be a medication that you could use, or if the client has had some severe adverse effects that happen with stimulant use.

06:33 Now the dose is going to be depending on the weight.

06:36 So for a child, if they're less than or equal to 70kg, you want to start a dose of 0.5mg/kg per day for a minimum of three days.

06:45 And then you can start to titrate it up to a daily dose of approximately 1.2mg/kg per day.

06:52 Now, the maximum daily dose should never exceed 1.4mg/kg per day, or 100mg, whichever is less. Remember, this requires your close observation and communication with the client and the family. Now, if the client is greater than 70kg, well, you're going you're going to start at a dose of 40mg for at least three days.

07:14 Then you can titrate it up to 80mg.

07:16 Now you can increase to a maximum dose of 100mg after 2 to 4 weeks.

07:21 If the symptoms are still persisting and you haven't reached a dose that is applicable to your client. Now, again, I can't stress enough the observation and communication that needs to happen during this phase.

07:34 Now you can give this in oral capsules.

07:37 Most often it's given once a day.

07:39 Now the evening dosing is associated with fewer overall adverse effects than the morning dosing.

07:44 So you recommend that the patient takes it in the evening.

07:47 Now if you have to you can split it into two doses a day, but only in cases when the morning dose is too strong or the duration of action isn't what you're looking for.

07:57 So it will last 10 to 12 hours or more.

08:01 It will take 6 to 12 weeks.

08:02 So again, this is always something that's difficult for clients.

08:05 Help them understand it's going to take a long time for them to really get to the full therapeutic effect.

08:12 So it's going to take at least 6 to 12 weeks before the patient will really experience a therapeutic effect.

08:20 Now you have to give this every day and there should be no drug holidays.

08:24 So unlike the stimulants, this is not a medication you want to stop on the weekends.

08:28 This has to be given every day.

08:32 Now, if you do have to discontinue it abruptly, you can do it.

08:36 But you want to be sure to watch for these symptoms because the withdrawal symptoms of Atomoxetine could be rebound ADHD symptoms and they can be worse.

08:45 They could be irritable and mood changes.

08:47 They're going to be really tired.

08:48 Their sleep is going to be disrupted.

08:50 They have some significant GI problems.

08:53 They have nausea and GI discomfort and even headaches.

08:57 So it's best to not discontinue it abruptly.

09:00 But if for some reason you have to watch for signs of the withdrawal symptoms and make sure you educate your clients so they know what signs to expect and watch for.

09:10 It's also a way to help a client adhere to the medication System to let to let them know, hey, listen, please don't just stop this abruptly because you could have some really uncomfortable symptoms that would follow.

09:21 Now you're going to want to make sure for atomoxetine, for this medication, you monitor heart rate and blood pressure, their height and weight.

09:29 Remember, they can also have those GI disturbances watch their liver enzymes because they can have that idiosyncratic issue and also monitor their renal function.

09:39 As a provider, you're going to help your clients manage these adverse effects for atomoxetine. Now if they're just mild, you might not have to do anything.

09:46 The mild symptoms may resolve over time.

09:49 You could also try dividing a single daily dose into two doses, like we talked about, and that may be enough to address those adverse symptoms.

09:56 However, if they're having psychotic or manic symptoms or suicidal ideation, of course you would discontinue this medication.

10:05 So this would not be something you wean off.

10:07 Remember, you can stop it abruptly.

10:09 It just may be some really uncomfortable side effects for your client.