ADHD Nonstimulants: Tricyclic Antidepressants

00:01 Hi, I'm Doctor Rhonda Lawes and this is going to be a discussion on the use of non stimulants in the treatment of ADHD.

00:07 Now specifically we're going to focus on antidepressants.

00:11 So we'll talk about the indications for this.

00:13 But keep in mind these are an off label use.

00:15 And usually off label uses are typically not as effective as stimulants.

00:20 But there's really good reasons why you might prescribe this.

00:24 So we have tricyclic antidepressants and we'll call those TCAs and dopamine reuptake inhibitors. So these are usually reserved for clients that have some of the following experiences. So as you're preparing for practice these would be some potential use cases. If your client has had a poor response to a trial of stimulants of snris or alpha two adrenergic agonists, this is an option you could consider.

00:48 Maybe the patient has tried one of those other medications and they just couldn't tolerate the adverse effect.

00:54 A TCA or a dopamine reuptake inhibitor might be a good alternative.

00:59 And lastly, if the client has significant coexisting conditions like anxiety or depression, this might be the best choice for them.

01:08 Now there's a boxed warning given by the FDA for all antidepressants because of the increased risk of suicidal thinking and behavior.

01:16 So you always want to keep that in mind.

01:18 You want to monitor your patients closely for clinical, worsening suicidal thoughts or unusual changes in behavior.

01:26 It doesn't mean your client will experience this, but you want to be on the alert and the lookout for that. And you want to educate your clients to report any of these feelings or thoughts they may be experiencing.

01:37 So let's look at the mechanism of action of the TCA.

01:41 Now you see we have the presynaptic neuron and the postsynaptic neuron.

01:46 Look there at the first little bullet point we have.

01:49 Now this medication a TCA inhibits the reuptake of norepinephrine and serotonin.

01:55 So you know, anything that inhibits the reuptake of these Of these neurotransmitters means more of those substances are going to be in the synaptic cleft and available to the brain. So this is what increases the amount of those neurotransmitters that are available. Now there are some other receptors that are affected.

02:11 You've got the serotonin five two.

02:14 You've got the histaminergic H1 and the alpha one adrenergic and the muscarinic receptors. So you've got a lot going on with this one medication.

02:25 There's a wide range of physiological effects for TCAs for a good reason because there are so many of those receptors involved.

02:33 Let's walk through those because we know we're going to have increased norepinephrine, increased serotonin.

02:38 You've got the adrenergic impact the histamine and the muscarinic.

02:42 So let's start with increase in norepinephrine.

02:44 What does that do for somebody with ADHD.

02:47 Well it helps them address their problems with inattention and hyperactivity.

02:52 Now it does this because it corrects the relatively low levels of norepinephrine, Nephron, particularly in the prefrontal cortex.

02:59 And that's where you have all the executive functioning going on.

03:03 Now the increased serotonin that goes to mood regulation.

03:06 Now this can help the client monitor their or impact their impulse control by indirectly modulating their dopamine activity in the brain.

03:15 Now the adrenergic antagonism is going to have some cardiovascular effects.

03:19 I'll go into those in detail in just a minute.

03:21 The histamine antagonism, that's what gives you the sedative properties and the muscarinic antagonism has all those anticholinergic effects.

03:30 So now let's drill down on some of those adverse effects that can lead to contraindications with TCAs.

03:36 There is a risk for cardiovascular events things like heart block, ventricular arrhythmias and sudden death.

03:44 Now those are the most severe.

03:45 But they can also experience a mild increase in their diastolic blood pressure and their pulse rate. Patients on TCAs report weight gain, which really is not helpful for anyone.

03:56 They don't like the anticholinergic effects, particularly that dry mouth feeling that they have. They can feel really tired.

04:03 Another risk is that it can lower the seizure threshold if the patient has a history of that. That's something you're going to want to be aware of or consider not using this medication.

04:13 Now, rarely this could bring on thoughts of suicidal ideation.

04:17 So with any medication you want to make sure you're having that conversation with your client. Build a relationship of trust while they feel safe to report that to you.

04:26 Now let's look at the contraindications.

04:28 Now once you remember the adverse effects, the contraindications are obvious.

04:33 You wouldn't want to give a TCA to anyone with cardiovascular disease, and particularly not anyone with any cardiac conduction abnormalities if they've got arrhythmias.

04:42 Again, that would be a definite and clear cardiovascular contraindication.

04:47 Also, because it lowers the seizure threshold, you wouldn't want to give it to somebody with a seizure disorder, and you wouldn't want to give it with someone who's also on a serotonergic agent.

04:59 Now, before you prescribe a TCA, all the reasons we've just talked about the adverse effects or contraindications, you want to make sure that you have a patient's history and family history. That's very thorough.

05:10 Make sure the parents or guardians are aware of the risk of suicidal ideation.

05:15 Make sure you get an ECG to screen for disorders of the cardiac system.

05:19 And consult your Drug Interactions database to see if there's any interactions with TCAs.

05:24 Now when you're prescribing this, it's typically formulated as a tablet or a capsule for oral use. Of course, you're going to want to start at a low dose.

05:32 You can titrate this medication weekly, but it needs to be taken every day.

05:37 No drug holidays with TCAs.

05:39 And make sure they monitor the heart rate and the blood pressure as a baseline.

05:43 And during the treatment.

05:44 Now when you're discontinuing a TCA, make sure that you taper it to avoid severe withdrawal effects.