HMS vs PROMETHEGAN

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated August 22, 2026·How we rate

Possible drug interaction. HMS and PROMETHEGAN 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	HMS	PROMETHEGAN
Rating	72/100	70/100
Pharmacy pays	—	~$1.53 /30
Type	RX	RX
Active ingredient	MEDRYSONE	PROMETHAZINE HYDROCHLORIDE
Manufacturer	Allergan	Cosette
Dosage forms	Suspension	Suppository
Drug class	—	Phenothiazine
Boxed warning	None	Boxed warning
Half-life	—	about 9 to 16 hours
Treats	Allergic Conjunctivitis, Drug Hypersensitivity, Scleritis	Anaphylaxis, Allergic Conjunctivitis, Motion Sickness

hms promethegan

Rating

72/100

70/100

Pharmacy pays

—

~$1.53 /30

Type

Active ingredient

MEDRYSONE

PROMETHAZINE HYDROCHLORIDE

Manufacturer

Allergan

Cosette

Dosage forms

Suspension

Suppository

Drug class

—

Phenothiazine

Boxed warning

None

Boxed warning

Half-life

—

about 9 to 16 hours

Treats

Allergic Conjunctivitis, Drug Hypersensitivity, Scleritis

Anaphylaxis, Allergic Conjunctivitis, Motion Sickness

Frequently asked questions

Which is better-rated, Hms or Promethegan?

By our independent rating, Hms scores higher — 3.6 vs 3.5 out of 5 for Promethegan. Ratings are based on FDA regulatory (recall-safety) data.

What is the difference between Hms and Promethegan?

Hms contains Medrysone, while Promethegan contains Promethazine 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.