Yes. A lawful prescription does not automatically prevent a DUI charge if law enforcement believes the medication caused impairment while driving. Mississippi law focuses on whether the person was impaired rather than solely on whether the substance was prescribed. Officers consider observations of behavior, field sobriety test performance, and any chemical tests administered. A prescription can provide important context and evidence that lawful medication use does not equate to impairment, but it does not inherently shield a driver from investigation or charges. If you are facing such a charge, documenting prescriptions, dosage instructions, and medical provider guidance can help explain responsible use and timing relative to driving. Early legal consultation helps ensure records are preserved and that procedural challenges to testing or the stop itself are raised promptly. These steps are important for building a defense that demonstrates lawful treatment and addresses whether actual impairment was present at the time of driving.