Can i give my 6 year old son ritalin (methylphenidate) 10 mg while he's taking his asthma meds, albuterol and pulmacort respuse in his nebuliser?

Yes, you can: There is no contra-indication to continue to treat your son with ritalin, (methylphenidate) if he has been on the drug. If he has not taken the drug before, i would wait until his asthma is better. More importantly, at age 6 your son should be taught how to use a regular inhaler rather than a nebuliser. If he has not seen an asthma specialist, he should.