Dexmethylphenidate, sold under the trade names Focalin among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It is in the phenethylamine and piperidine classes of medications. It is the active dextrorotatory enantiomer of methylphenidate.
1 Some allergies cause digestion problems as well. There are also times when you may feel nauseous after every meal. Nausea after meals can also be accompanied with other allergic symptoms, such as, hives or rashes.  Psychological â Sometimes, nausea after eating may also occur due to psychological factors.
Patients often feel unwell after fainting. They may complain of symptoms including nausea, abdominal pain, clamminess, tremors, lightheadedness, headache, malaise, exhaustion and confusion. Mechanisms and Causes of NCS. When a person stands up, the pull of gravity causes blood to pool in the lower extremities.