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PROMETHEGAN vs VONTROL

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated September 30, 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.

prometheganvontrol

Rating

70/100
72/100

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

Frequently asked questions

Which is better-rated, Promethegan or Vontrol?

By our independent rating, Vontrol 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 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.