ISONIAZID vs RIFADIN

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated August 17, 2026·How we rate

Possible drug interaction. ISONIAZID and RIFADIN 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	ISONIAZID	RIFADIN
Rating	70/100	70/100
Pharmacy pays	~$96.88 /30	~$20.59 /30
Type	RX	RX
Active ingredient	ISONIAZID	RIFAMPIN
Manufacturer	Watson Labs	Sanofi Aventis US
Dosage forms	Injectable, Solution, Tablet	Injectable
Drug class	Antimycobacterial	Rifamycin Antibacterial
Boxed warning	None	None
Treats	Tuberculosis	Brucellosis, Haemophilus Infections, Legionnaires' Disease

isoniazid rifadin

Rating

70/100

Pharmacy pays

~$96.88 /30

~$20.59 /30

Type

Active ingredient

ISONIAZID

RIFAMPIN

Manufacturer

Watson Labs

Sanofi Aventis US

Dosage forms

Injectable, Solution, Tablet

Injectable

Drug class

Antimycobacterial

Rifamycin Antibacterial

Boxed warning

None

Treats

Tuberculosis

Brucellosis, Haemophilus Infections, Legionnaires' Disease

Frequently asked questions

Which is better-rated, Isoniazid or Rifadin?

Isoniazid and Rifadin are tied at 3.5 out of 5 by our independent rating.

Which is cheaper, Isoniazid or Rifadin?

Rifadin costs pharmacies less to acquire — about $20.59 vs $96.88 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 Isoniazid and Rifadin?

Isoniazid contains Isoniazid, while Rifadin contains Rifampin — 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.