Can i have a bad reaction from taking luminal (phenobarbital)?

Yes: Luminal is a trade name for phenobarbital, an anepileptic drug with serious potential side effects, including agitation, anxiety, ataxia, CNS excitation or depression, confusion, dizziness drowsiness, hallucinations, “hangover” effect, headache, hyperkinesia, impaired judgment, insomnia, lethargy, nervousness, nightmares, somnolence, and b/p increase.