Why do Rx to OTC Conversions occur?

A prescription medication (Rx) is converted to over-the-counter (OTC) when a common condition being treated is easily identified by patients and the medicine can be safely used by patients without needing to be monitored by a healthcare provider.

Product Characteristic Requirements
  • The consumers can self-diagnose, self-treat, and self-manage the condition
  • No health practitioner is needed for the safe and effective use of product
  • Product has low potential for misuse and abuse
  • Safety margin of benefit outweighs the risks
What steps are required by the FDA?
  1. Rx safety and efficacy data can be utilized for FDA review before conversion to OTC
  2. Rx prescription label must be translated to consumer-friendly terms
  3. Consumer studies must be evaluated to determine usability
    • Label Comprehension Study: can the public understanding the key label messages?
    • Self-Selection Study: can the public select the right product?
    • Actual Use Study: can the public follow the labeled directions?
    • Human Factor Study: can the public use the product correctly?
  4. Submit a New Drug Application (NDA)
Who Can Request an OTC Switch?
  • Holder of an approved prescription NDA
  • Citizen petition

Both scenarios still require full scientific data to support the switch.

Recent examples of products now available over-the-counter without a prescription: 

Pataday Once Daily Relief (olopatadine HCl 0.7%)

  • Indication: allergic conjunctivitis
    • Dose: 1 drop into each eye daily
  • Administration: do not insert contact lenses within 10 minutes of application and wait 5 minutes before using other eye drops
  • Adverse Effects: headache, eye irritation
  • MOA: Histamine H1-antagonist
  • Compelling reasons to support OTC Conversion:
    • Previously few options for OTC topical antihistamine for the eyes
    • Less systemic side effects such as drowsiness commonly resulting from antihistamines taken by mouth 

Voltaren Gel (diclofenac sodium 1%)

  • Indication: arthritis pain
    • Lower extremities: 4 g to affected area up to 4 times a day as needed
    • Upper extremities: 2 g to affected area up to 4 times a day as needed
  • Administration: Apply to clean, dry, intact skin. Do not to open wounds, eyes, or mucous membranes. Do not cover with occlusive dressing or apply heat, sunscreens, cosmetics, lotions, moisturizers, insect repellent, or other topicals. Avoid showering at least 1 hour after application and avoid sunlight exposure to affected area. Make sure to apply to entire joint and affected area.
    • Not to be used for more than 21 days or more than 2 body parts at the same time
  • Adverse Effects: scaling or dryness where it was applied
  • MOA: reversibly inhibits COX-1 and COX-2 enzymes, decreasing inflammation
  • Compelling reasons to support OTC Conversion:
    • Previously no OTC topical anti-inflammatory medicine for pain
    • Provides an option for a localized condition such as knee or shoulder pain
    • Safer compared to OTC anti-inflammatory drugs taken by mouth, such as ibuprofen and naproxen, because it avoids side effects such as increased risk of bleeding and stomach ulcers

Prepared By: Allen Su, PharmD Candidate 2021


Prescription to Over-the-Counter (OTC) Switch List. US Food and Drug Administration.

Regulatory Approaches for Prescription to OTC Switch. Theresa M. Michele, M.D. US Food and Drug Administration.

Pataday Drug Labeling & Voltaren Drug Labeling