Drug Nomenclature and Errors

Prescription Errors

  • Statistics: 7,000-9,000 people die annually in the US due to documented medication errors.
  • Cost: Medication-associated errors cost over $$40 billion per year.
  • Stages of Errors: Errors occur most commonly during ordering or prescribing but can also happen during administration, dispensing, and monitoring.
  • Common Errors: Providers may prescribe the wrong medication name or dosage.
  • Physical Therapist's Role: Physical therapists can detect unexpected side effects and refer patients to pharmacists or physicians to improve health outcomes and reduce healthcare spending.

Drug Nomenclature

  • Drug naming is a primary source of confusion.
  • Examples:
    • Celebrex (analgesic)
    • Cerebyx (anti-seizure)
    • Celexa (antidepressant)
  • Prescribing errors can lead to hospitalization.

Polypharmacy

  • Definition: The use of 5 or more drugs, including prescribed medications and supplements.
  • Concern: A growing concern, especially for older adults with multiple chronic conditions.
  • Commonly Used Drugs: Cholesterol, high blood pressure, and diabetes medications.
  • Challenges: Polypharmacy can be expensive, difficult to track, and hard to monitor, particularly for homebound individuals or those in rural areas.

Drug Names

  • All drugs have at least three names:
    • Chemical Name: The drug's chemical composition.
    • Generic Name: Also known as the scientific name.
    • Trade/Brand Name: Proprietary name from the manufacturer; has a registered trademark and restricted use until the patent expires.

Examples of Drug Names

  • Antibiotic Example: Ampicillin
    • Chemical Name: 6-aminopenicillanic acid
    • Trade Names: Amoxil, Omnipen, or Polycillin

Generic vs. Brand-Name Drugs

  • Bioequivalence: Generic drugs must be bioequivalent to their brand-name counterparts.
    • Same amount of active ingredients
    • Same route of administration
    • Same therapeutic effects
    • Same safety profile
  • Different Effects: Patients can respond differently to generic drugs due to individual variability factors.
  • Rehabilitation Specialists: Should refer patients to a physician or pharmacist if they have concerns about the effects of a generic drug.

FDA Approval

  • The Food and Drug Administration (FDA) must approve new prescription drugs before they can be sold to the public.
  • 2022 Approvals: The FDA approved 37 new drugs for use by the general public.
  • Approval Process: Extensive and can take several years.

FDA Review Timeline

  • Average Review Time: Once research shows a drug is safe and effective, the FDA typically reviews and either approves or denies an application within an average of 10 months.

Drug Approval Process

  • Manufacturers follow a series of steps:
    • Pre-clinical animal studies (measure toxicity and effectiveness)
    • File an investigational new drug (IND) application
    • Clinical trials in human subjects (Phases 1-3)

Clinical Trial Phases

  • Phase 1:
    • Emphasis: Safety
    • Subjects: Healthy volunteers (20-80 subjects)
  • Phase 2:
    • Emphasis: Drug's effectiveness in treating a specific condition
    • Subjects: Hundreds of individuals with the condition
    • Method: Controlled trials comparing the drug to a placebo or different treatment
  • Phase 3:
    • Emphasis: Safety and effectiveness in a larger population
    • Subjects: Thousands of subjects
    • Dosages: Tested at different dosages

New Drug Application (NDA)

  • At the end of Phase 3 trials, the drug sponsor submits an NDA to the FDA.
  • Includes all animal and human data, and analyses of that data.
  • Information on how the drug behaves in the body and how it is manufactured.
  • If requirements are met, the FDA approves the application, and the drug is ready for marketing.

Post-Marketing Surveillance (Phase 4)

  • Monitoring safety issues after drugs are on the market; an indefinite process.

Rare Diseases

  • The FDA makes provisions for the development, approval, and production of drugs to treat rare diseases.

Off-Label Prescribing

  • Definition: Prescribing a drug for a different purpose than what the FDA approved.
  • The drug is being used in a way not described on its label.
  • Example: Glucophage (metformin), approved for reducing blood glucose in type 2 diabetes mellitus, is prescribed to manage weight gain in people taking antipsychotic medications, even though it is non-FDA-approved for this indication.

Drug Schedules

  • Drugs with the potential for abuse are categorized into schedules.
  • Schedule I:
    • Highest potential for abuse
    • No currently accepted medical use in the United States
    • Examples: Heroin or ecstasy
  • Schedules II, III, IV, and V:
    • The potential for abuse decreases from II to V.
  • Schedule V:
    • Medications containing limited quantities of certain opioids.
    • Examples: Those used for cough suppression or over-the-counter antidiarrheal agents.