promethazine vs zaleplon
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Side-by-side comparison of promethazine and zaleplon. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
Promethazine: Coadministration of a single dose of zaleplon and promethazine (10 and 25 mg, respectively) resulted in a 15% decrease in maximal plasma concentrations of zaleplon, but no change in the area under the plasma concentration-time curve. However, the pharmacodynamics of coadministration of zaleplon and promethazine have not been evaluated.
Phenergan
Sonata
Promethazine suppositories are a medicine that can help with allergies, motion sickness, nausea, vomiting, and sleep problems. It works by blocking certain natural substances in your body.
Zaleplon (Sonata) is a medicine that helps you fall asleep faster. It is used for short-term treatment of insomnia.
This medicine can treat allergy symptoms like a runny nose or itchy eyes. It can also help prevent motion sickness. Promethazine can also be used to control nausea and vomiting, especially after surgery. Sometimes, it's used to help you relax or sleep before or after surgery.
Zaleplon is used to treat insomnia, which means you have trouble falling asleep. It can help you fall asleep faster for up to 30 days. However, it does not increase the total time you sleep or decrease the number of times you wake up during the night.
Promethazine belongs to a class of drugs called antihistamines and antiemetics. It works by blocking histamine, a substance in the body that causes allergic symptoms. It also affects the part of the brain that controls nausea and vomiting.
Zaleplon is a non-benzodiazepine hypnotic. It works by slowing activity in the brain to allow sleep. It affects certain brain chemicals to help you fall asleep.
- • Drowsiness
- • Dry mouth
- • Blurred vision
- • Dizziness
- • Headache
- • Dizziness
- • Somnolence (sleepiness)
- Nausea 2,530
- Vomiting 1,734
- Pain 1,453
- Fatigue 1,408
- Diarrhoea 1,271
- Nausea 111
- Completed Suicide 88
- Insomnia 80
- Headache 79
- Fall 77
Promethazine suppositories should not be used in children under 2 years old because it can cause serious breathing problems, which can be fatal. Use with caution in children 2 years and older, and use the lowest effective dose. Avoid giving this medicine with other drugs that can also cause breathing problems.
Zaleplon can cause complex sleep behaviors like sleepwalking, sleep-driving, and doing other activities while not fully awake. Some of these activities can result in serious injuries or even death. Stop taking zaleplon immediately and call your doctor if you experience any of these behaviors. Zaleplon can be habit-forming. Keep it in a safe place to prevent misuse.
Tell your doctor if you are pregnant or breastfeeding before using this medicine. It is not known if promethazine can harm an unborn baby or pass into breast milk.
It is not known if zaleplon can harm your unborn baby. Talk to your doctor if you are pregnant, plan to become pregnant, or are breastfeeding.
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How to Read This promethazine vs zaleplon Comparison
promethazine is classified in the Phenothiazine Antiemetic / Antihistamine drug class, while zaleplon sits within the Non-Benzodiazepine Hypnotic (Z-Drug) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, promethazine has 8,396 submissions while zaleplon has 435. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to promethazine slightly reduces the highest level of zaleplon in your blood, but the total amount in your body remains about the same.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for promethazine or zaleplon.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.