Phenergan Dosage Guide and Treatment Information
What is Phenergan?
Phenergan contains promethazine hydrochloride, a phenothiazine-class antihistamine. Unlike newer antihistamines, Phenergan crosses the blood-brain barrier, causing sedation that makes it useful for multiple conditions. EverydayMeds stocks both Phenergan 25mg tablets (56 tablets) and Phenergan Elixir 5mg/5ml oral solution (100ml) for flexible dosing options.
How Phenergan Works
Promethazine blocks histamine H1 receptors, preventing allergic reactions like runny nose, sneezing, and itching. Its anticholinergic properties help reduce nausea, whilst dopamine receptor blocking provides anti-sickness effects. The sedating action occurs because the medication readily enters brain tissue, making it effective for short-term sleep difficulties.
Conditions Treated
Phenergan treats hay fever, allergic rhinitis, urticaria (hives), and itchy skin conditions. For travel, it prevents motion sickness when taken before journeys. The anti-nausea properties help with vomiting and vertigo. Short-term insomnia may respond to Phenergan's sedating effects, though it should not replace proper sleep hygiene practices.
Dosage Information
For allergies, adults typically take 25mg at bedtime or 10-20mg twice daily. Sleep problems may require 25-50mg at bedtime for short periods only. Motion sickness prevention involves 25mg the night before travel, followed by 25mg that morning. The elixir allows precise dosing, particularly useful for those who struggle with tablets or require smaller doses.
Important Safety Considerations
Phenergan causes drowsiness that may persist into the next day. Avoid driving, operating machinery, or drinking alcohol whilst using this medication. Some people experience dry mouth, blurred vision, or constipation due to anticholinergic effects. Elderly patients may be more sensitive to these side effects and should start with lower doses.
