PROMETHAZINE PLAIN vs THORAZINE

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated August 16, 2026·How we rate

Possible drug interaction. PROMETHAZINE PLAIN and THORAZINE are different prescription medicines. Combining or switching between them can cause interactions — talk to a pharmacist or prescriber before making changes. This page is not medical advice.

Attribute	PROMETHAZINE PLAIN	THORAZINE
Rating	New	70/100
Pharmacy pays	~$1.53 /30	~$12.04 /30
Type	RX	RX
Active ingredient	PROMETHAZINE HYDROCHLORIDE	CHLORPROMAZINE HYDROCHLORIDE
Manufacturer	Pharmobedient	Glaxosmithkline
Dosage forms	Syrup	Tablet, Capsule, extended release
Drug class	Phenothiazine	Phenothiazine
Boxed warning	Boxed warning	None
Half-life	about 9 to 16 hours	—
Treats	Anaphylaxis, Allergic Conjunctivitis, Motion Sickness	Anxiety Disorders, Child Behavior Disorders, Hiccup

promethazine plain thorazine

Rating

New

70/100

Pharmacy pays

~$1.53 /30

~$12.04 /30

Type

Active ingredient

PROMETHAZINE HYDROCHLORIDE

CHLORPROMAZINE HYDROCHLORIDE

Manufacturer

Pharmobedient

Glaxosmithkline

Dosage forms

Syrup

Tablet, Capsule, extended release

Drug class

Phenothiazine

Boxed warning

None

Half-life

about 9 to 16 hours

—

Treats

Anaphylaxis, Allergic Conjunctivitis, Motion Sickness

Anxiety Disorders, Child Behavior Disorders, Hiccup

Frequently asked questions

Which is cheaper, Promethazine Plain or Thorazine?

Promethazine Plain costs pharmacies less to acquire — about $1.53 vs $12.04 for a 30-count supply, per the CMS NADAC survey. That gap is in the pharmacy's cost of goods, not necessarily in what you pay: your price is set afterwards by your insurer and the pharmacy.

What is the difference between Promethazine Plain and Thorazine?

Promethazine Plain contains Promethazine Hydrochloride, while Thorazine contains Chlorpromazine Hydrochloride — they have different active ingredients.

Ratings are based on FDA regulatory (recall-safety) data. This comparison is for general reference only — not medical advice. Always consult a licensed professional before choosing or switching a medication.