When taking Concerta, alcohol use should be limited. Even though there is no interaction specified between the two, consuming alcohol can magnify the side effects of Concerta, according to WebMD.
This is especially important to consider in the first few weeks of treatment when the body is adjusting to the medication. With side effects such as dizziness and nervousness, one's ability to concentrate on tasks such as driving or operating heavy machinery may be impaired; and, adding alcohol to the mix has the potential of intensifying that impairment to dangerous levels. While alcohol use is not specifically prohibited when one takes Concerta, WedMD states that alcohol consumption should be restricted.