Hi,
Yes, it may cause Parkinson like symptoms on prolonged use. Phenergan is a phenothiazine derivative with anti-histaminic,
anticholinergic and anti-dopaminergic properties. By virtue of its anti-histaminic properties it is commonly prescribed to treat allergic conditions, nausea and vomiting, and
motion sickness as well to provide sedation.
Its common side effects include profound sedation, confusion, and disorientation, which may impair physical and mental abilities due to anti-histaminic properties. Due to anticholinergic properties, it may cause side effects, which include blurred vision, dry mouth, dilated pupils, constipation, and
urinary retention. Due to its anti-dopaminergic properties it may cause
extrapyramidal symptoms, which include acute dystonia, akathisia, and
tardive dyskinesia.
Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Mohammed Taher Ali, General & Family Physician