Niacinamide (+ tetracycline)

What is this medication for?

• Discoid lupus erythematosus (DLE) — with tetracycline, 25–65% control; pemphigus erythematosus/foliaceus adjunct; lupoid onychodystrophy, sterile pyogranuloma, dermatomyositis, GSD metatarsal fistulae; NOT effective for atopic dermatitis

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• The DLE workhorse before escalating to immunosuppression: nose-mirror lupus (DLE) in a dog → niacinamide + tetracycline every 8 hours + vitamin E + sunlight avoidance is the classic first ladder.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Anorexia, vomiting, low energy/tiredness (Main effects (reduce niacinamide first))

Worth a phone call to your veterinarian

• Liver enzyme increases (Occasional)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Liver disease, active peptic ulcers, hypersensitivity
• has or has had: Diabetics — insulin/oral-agent adjustments (human niacin-class)

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Tetracycline
  • Carbamazepine/primidone (human)
  • Antidiabetics

Storage and handling

Inexpensive OTC — the cost appeal of the whole regimen.

Good to know

• The DLE workhorse before escalating to immunosuppression: nose-mirror lupus (DLE) in a dog → niacinamide + tetracycline every 8 hours + vitamin E + sunlight avoidance is the classic first ladder.
• Banded simplicity (500/250/100 mg by size) makes it an owner-friendly regimen; steroids get spared.
• 6–8 week verdict — counsel patience, not failure, at week 2.