PROMETHEGAN vs VONTROL

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated August 20, 2026·How we rate

Possible drug interaction. PROMETHEGAN and VONTROL 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	PROMETHEGAN	VONTROL
Rating	70/100	70/100
Pharmacy pays	~$1.53 /30	—
Type	RX	RX
Active ingredient	PROMETHAZINE HYDROCHLORIDE	DIPHENIDOL HYDROCHLORIDE
Manufacturer	Cosette	Glaxosmithkline
Dosage forms	Suppository	Tablet
Drug class	Phenothiazine	—
Boxed warning	Boxed warning	None
Half-life	about 9 to 16 hours	—
Treats	Anaphylaxis, Allergic Conjunctivitis, Motion Sickness	Nausea, Vertigo, Vomiting

promethegan vontrol

Rating

70/100

Pharmacy pays

~$1.53 /30

—

Type

Active ingredient

PROMETHAZINE HYDROCHLORIDE

DIPHENIDOL HYDROCHLORIDE

Manufacturer

Cosette

Glaxosmithkline

Dosage forms

Suppository

Tablet

Drug class

Phenothiazine

—

Boxed warning

None

Half-life

about 9 to 16 hours

—

Treats

Anaphylaxis, Allergic Conjunctivitis, Motion Sickness

Nausea, Vertigo, Vomiting

Frequently asked questions

Which is better-rated, Promethegan or Vontrol?

Promethegan and Vontrol are tied at 3.5 out of 5 by our independent rating.

What is the difference between Promethegan and Vontrol?

Promethegan contains Promethazine Hydrochloride, while Vontrol contains Diphenidol 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.