Can you tell me is phenergan (promethazine) harmful to take long term?

Consider this info: Most common side effects of Phenergan (promethazine) are drowsiness, dizziness, anxiety, blurred vision, dry mouth, stuffy nose, ringing in your ears, weight gain, swelling in your hands or feet, impotence, trouble having an orgasm, or constipation. Try this link for more info regarding long-term use: http://www.webmd.com/drugs/2/drug-9412/phenergan+injection/details