Complete Side Effects Profile for Promethazine
Common Side Effects (Affect 1 in 10 People)
The most frequently reported side effects of promethazine include drowsiness and sedation, which typically occur within 30-60 minutes of taking the medicine. Dry mouth affects many users due to the anticholinergic properties of promethazine. Other common effects include dizziness, blurred vision, and constipation. These effects are generally mild and may reduce as your body adjusts to the medication.
Less Common Side Effects (Affect 1 in 100 People)
Some people experience headaches, confusion, or difficulty concentrating whilst taking promethazine. Nausea and stomach upset occasionally occur, particularly when starting treatment. Skin reactions such as rash or increased sensitivity to sunlight may develop. Restlessness or agitation can affect some individuals, especially children and elderly patients. EverydayMeds stocks both Phenergan 25mg tablets and 5mg/5ml elixir to suit different preferences and dosing requirements.
Serious Side Effects (Rare but Important)
Severe allergic reactions including difficulty breathing, swelling of face, lips, or throat require immediate medical attention. Involuntary muscle movements or tremors may indicate a serious reaction. Yellowing of skin or eyes could suggest liver problems. Fast or irregular heartbeat warrants medical review. High fever with muscle stiffness requires urgent assessment as this may indicate a rare but serious condition.
Age-Specific Considerations
Children may experience paradoxical effects including hyperactivity, restlessness, or sleep disturbances rather than sedation. Elderly patients face increased risk of confusion, falls due to dizziness, and anticholinergic effects. Pregnant women should consult healthcare providers before using promethazine, especially in the third trimester. Breastfeeding mothers should seek medical advice as promethazine passes into breast milk.
Managing Side Effects Effectively
Taking promethazine with food may reduce stomach upset and nausea. Staying hydrated helps combat dry mouth effects. Avoiding alcohol reduces drowsiness and dizziness risks. Using sunscreen prevents photosensitivity reactions. Starting with lower doses allows assessment of individual tolerance. EverydayMeds provides detailed patient information leaflets with all promethazine products to support safe usage.
