Guanfacine (Intuniv, Tenex)
Intuniv, a long acting form of guanfacine (Tenex), is a relatively new ADD medication so there has not been a lot of community experience with it. Currently it is primarily used as an adjunct to the stimulants, which remain the first line treatment for ADD. It is often used when the stimulants fail to have an optimal effect, especially when impulsivity is a problem.
The medication may take three or four weeks to have an effect. This makes it somewhat difficult to judge its effects since it is sometimes difficult to compare a person’s condition before he started it with his condition four weeks or three months later. For this reason, it can be useful for the patient and prescribing clinician to agree upon the specific target symptoms for which the medication is being prescribed and score them on a scale of 0 (no symptoms) to 5 (seriously disturbing symptoms) at the time the mediation is begun, then periodically afterward. Using numbers can help since most people don’t have the words to describe the difference between various degrees of impulsivity.
Intuniv should be started slowly starting with 1 mg per day for about a week. If there is no or less than optimal effect, it can be increased to 2 mg for a few weeks, then to 3 mg or 4 mg per day depending on the patient’s response. The most common adult dose is 3 mg per day, but each patient’s dose needs to tailored individually.
The most common side effects are dryness of the mouth and tiredness. To minimize the averse effects of the tiredness, some clinicians suggest patients take the medication at bedtime since the tiredness wears off more quickly than does the anti-impulsivity effect, which lasts well into the following day. The sedative effect may be also be helpful to patients who have sleep problems, which are not uncommon among people with ADD. In addition, stimulants make it difficult for some patients to fall asleep and Intuniv may help with that problem.
In a study of 813 children and adolescents, researchers found that sedation decreased over time. If patients were able to tolerate the starting dose, it was likely they would be able to tolerate a higher dose without additional sedation. The degree of sedation was not found to be related to the patients’ weight or age or the magnitude of change in the dose. Patients who drive cars or operate machinery should be informed of the sedating effects of the medication.
Stopping the medication suddenly does not appear to be a problem for most people. However, it the person has high blood pressure and takes Intuniv, it may lower their pressure. Then stopping suddenly may result in a potentially dangerous elevation of the pressure.
Since Intuniv is not a stimulant, there are no problems with potential drug abuse, with phone-in refills, or prior authorizations.
If you are being treated with Intuniv, let me know about your experience with it at MarcDSchwartzMD@GMail.com
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Faraone, V et al: Effects of extended-release guanfacine on ADHD symptoms and sedation-related adverse events in children with ADHD J. Atten. Disord. 2010:13:532-538
