Aphthous ulcers (canker sores)
Clinical basis & sources
- Primary source
- OCP Minor Ailments Prescribing
Sources used
- Minor Ailments: Drug Classes and Specified DrugsOntario College of Pharmacists · 2026
- Executive Officer Notice: Update to Funding for Minor Ailment Services in Ontario Pharmacies (Effective July 1, 2026)Government of Ontario · 2026-05-19
- Management of Aphthous UlcersAmerican Family Physician · 2000
- Recurrent Aphthous StomatitisMerck Manual Professional Edition · 2026
- Recurrent Aphthous StomatitisNCBI Bookshelf / StatPearls · 2023
- Ontario Regulation 256/24: GeneralGovernment of Ontario · 2026
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Allowable drugs under Schedule 4 (1)
Drugs an Ontario pharmacist may prescribe for Aphthous ulcers (canker sores) under O. Reg. 256/24, Schedule 4. Choice still depends on the assessment, contraindications, allergies, and product availability — this is the eligible list, not a recommendation.
- Triamcinolone
Symptoms this assessment screens
- Painful round or oval mouth ulcer
- Small ulcer, generally less than 1 cm
- Inside cheek, lip, soft palate, or floor of mouth
- Similar ulcers have happened before
- Pain affects eating, drinking, or brushing
- Trigger pattern: trauma, stress, acidic foods, or oral products
Red flags — any positive means refer
- Ulcer persists more than 2 to 3 weeks or is worsening
- Large, deep, severe, or multiple ulcers
- Fever, swollen glands, GI symptoms, weight loss, or feeling unwell
- Genital ulcers, eye inflammation, arthritis, rash, or other mucous-membrane lesions
- Blisters, lip/cold-sore pattern, clustered lesions, or suspected oral herpes simplex virus
- Immunocompromised status or recurrent severe disease
- Unable to maintain hydration or nutrition
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