Intuniv for treating ADHD
The FDA approved Shire’s Intuniv medication as a once-daily treatment for ADHD on September 3, 2009. Intuniv is an extended release formulation of guanfacine, a blood pressure med that has been on the market for quite some time.
There have only been several studies done into the efficacy, safety and profile of use of Intuniv for treating ADHD. So far, they say that Intuniv works somewhat less than the stimulants like Ritalin and Adderall and probably somewhat more than the traditional non-stimulants like Strattera.
30% of people can’t take or don’t respond to stimulants. Parents in particular have concerns about traditional treatment for their children – so there is a lot of excitement around Intuniv.
The pros: Intuniv could possibly fill a lot of the role as a non-stimulant treatment that Strattera was supposed to play but didn’t. It has a long duration of effect and can even be used in combination with stimulants. And the short acting form of Intuniv has been on the market for some time, so we know a little about its safety and side effects.
The cons: Intuniv is very new, and it is still unclear just how effective it works. Some studies have hinted at potential problems such as high rates of serious side effects such as fainting and possibly even suicidal thoughts. While the short acting form has been on the market, Intuniv is long lasting.
Remember, roughly 50% of medication side effects are discovered after it is released onto the market.
Efficacy
How well does Intuniv work?
The studies seem to show that Intuniv falls just short of sending ADHD symptoms into remission. Roughly 55% of those on Intuniv in one study reported significant improvement compared to 30% of those on placebo.
In one major study, on one scale, people who started with an ADHD score of around 40 and took Intuniv had their score go down to around 19 on average. The accepted number for remission of ADHD symptoms is a score of 18 or less.
Those who took Intuniv along with stimulants went from about a starting score of around 29 to around 13.
There are some more interesting hints towards Intuniv’s efficacy we found in that study. On the one hand, only 10% of participants said that they stopped specifically because they thought Intuniv wasn’t working that well. And of those taking Intuniv with stimulants, only one person stopped specifically because it wasn’t working well.
That said, around 80% of people in total dropped from that study. It was done over two years, but that is still a somewhat high number.
Other studies into Intuniv have had much lower drop out rates.
In another, smaller study, roughly 30% of people on placebo reported significant improvement, as compared to around 55% of those treated with Intuniv. This difference likely means that it has some benefit and is useful but falls short of the efficacy of the stimulants, which work in roughly 70% of those treated.
Analysis of that study concluded that at low doses Intuniv is about as effective as traditional non-stimulants, and at higher doses is superior to the current non-stimulants, such as Strattera, Wellbutrin, and possibly even Provigil.
Intuniv Side effects
Different studies show different side effect profiles for Intuniv. Some say that it has about the same rate of issues as placebo, while others show that around 10-15% stop using it because of some side effect. As far as psychoactive drugs, a 10-15% discontinuation rate due to side effects is on the lower/medium range.
The side effects of Intuniv also depend on its particular use. When used in combination therapy with stimulants, for instance, it has much less rates of sedation and sleepiness, and users seem to report less problems. This is probably because its sedative effects that lower blood pressure are counteracted by the stimulants effect of raising it.
Some of its side effects take time to start showing up, with sedation in particular starting after 3 weeks of treatment.
Most common:
30-40% report sleepiness
25% report headache
17% in one study reported upper respiratory tract infection
10% report sedation
Other common side effects include dizziness, nausea, irritability and reduced salivary flow.
Concerns
In one study, 5 participants out of 262 who took Intuniv experienced syncope, or “temporary loss of consciousness.” In layman’s terms, they fainted or blacked out.
The clinical trials dedicated to exploring safety did not have such incidences, and it’s possible that the syncope events were environmentally based. One of the sufferers, after all, had a history of such issues. And guanfacine has a long history of use. So while those numbers are alarming, they are explainable.
Other possible side effects that may be an issue: head injury, suicidal ideation.
Like with all psychoactive medications, people using Intuniv should be monitored for anything abnormal like increased feelings of depression.
Dosing
Intuniv is given typically anywhere from 1-4mg/per day. A dose typically lasts for 12 hours, but may have some effect for up to 24 hours.
Related posts:
Look deeper into it!
What you read appears to be the extension studies. There were two double-blind studies before the studies you read. Check Academy of Child and Adolescent Psychiatry 2009.
Also, this is so different than Atomoxetine so why would they market it against it. Atomoxetine is thought to be a norepinephrine inhibitor (mostly around the locus coruleus) and thought to increase dopamine in parts of the PFC. Intuniv is guanfacine extended release which is thought to be an Alpha 2-agonist with a high affinity for the 2A adrenergic receptor.
[...] the stimulants, and may even be useful in combination with them. There are problems, of course. As this blog has noted, some of the trials which led to its approval had a shockingly high rate of people fainting – [...]