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.
Hypothyroidism your body functions slow down, making you gain weight and feel tired all the time. Narcotic abuse can cause fatigue, shallow breathing, anxiety, euphoria, vomiting, confusion, and constipation. Premature labor happens before 37 weeks of pregnancy, and causes contractions, bleeding, cramps, and more.