Greetings, and thank you for the question. ADHD is the broad classification, further divided into hyperactive, inattentive, and combined subtypes. Medication treatment for ADHD is the same regardless of the type, however. In general, there are two broad classes of treatment: stimulant and non-stimulant. Stimulants have been around longer and are considered the "gold standard" of treatment.
Either general class will work for the inattentive kind, like your son has, but some are likely to work less well.
For example, in the non-stimulant family, I'd probably avoid Intuniv and clonidine for your son, since they seem to work better for the hyperactive kind.
Strattera would probably be a reasonable non-stimulant to try. Regarding the stimulant class, there are 2 families of stimulant: methylphenidate (MPA) and amphetamine (AMP) class. Either will work in primarily inattentive types of ADHD.
Each is further subdivided into short and long-acting. So, there are quite a number of medicines open and available for your son to use
He tried Strattera but was not very happy with it and stopped using it. So there is nothing just the easily distracted, short focus, wandering mind type? He is definitively not hyperactive. John
Precisely. But, given he did not like the Strattera, he should probably start with the MPA class, since the AMP class tends to be close in some respects to Strattera. Ritalin and Concerta are the most popular options, but Focalin and Metadate are also good options. Any one of them work quite well for the kind of symptoms you described in your son. I have a lot of patients like your son who do quite well on any one of those listed.
Please let me know if you have any further questions - I hope this was useful! Feedback is quite welcome. Best wishes to you and for your son!