Medicine Fundamentals: Administration, Action, and Types

Posted on Apr 5, 2025 in Medicine & Health

Medicine Definition

A medicine is a substance administered or applied to the body of a person or animal, capable of causing a curative, preventive, or diagnostic effect.

Drug Components

Active Ingredient

The component of a drug responsible for its pharmacological effect.

Excipient

An ingredient that facilitates the action of the active ingredient, for example, by aiding absorption or administration.

Routes of Drug Administration

  • Oral: Taken by mouth. Absorbed in the stomach/small intestine. Forms: capsules, tablets, pills, syrups.
  • Rectal: Inserted into the rectum via the anus. Absorbed via rectal mucosa. Form: suppository.
  • Inhalation: Breathed in via the mouth. Absorbed via lower respiratory tract mucosa. Form: spray/aerosol.
  • Topical: Applied directly to the affected area. Absorbed through skin or mucous membranes. Forms: lotion, ointment.
  • Sublingual: Placed under the tongue. Absorbed via sublingual mucosa. Form: tablet.

Five Phases of Drug Action in the Body

  1. Administration/Deposit: The drug is placed in the location from which it will be absorbed.
  2. Absorption: The drug moves from the administration site into the bloodstream.
  3. Distribution: The drug spreads throughout the organism.
  4. Biotransformation (Metabolism): The chemical alteration of the drug within different organs.
  5. Excretion: The expulsion of the drug or its metabolites from the organism.

Over-the-Counter (OTC) Medications

These medications, sometimes indicated by specific labels (like EFP in some regions), are often paid for entirely by the consumer. Examples include dimenhydrinate (e.g., Biodramina) or effervescent antacids (e.g., Eno fruit salt).

Storage Information

Note: A specific symbol (often a snowflake or *) may indicate that the medication should be stored in a refrigerator at a temperature between 2°C and 8°C.

Specific Administration Techniques

Ophthalmic Administration (Eye Drops/Ointments)

  • Description: Direct application of medication (drops, ointments) onto the eye or eyelids.
  • Procedure: Tilt the head back slightly. Gently pull down the lower eyelid to create a small pocket (conjunctival sac). Apply the medication into this pocket. Blink a couple of times to distribute the medication.

Oral Administration

  • Description: Introducing medications through the mouth. Forms include solids (tablets, capsules) and liquids (drops, syrups, suspensions).
  • Procedure: Swallow capsules and tablets whole with a large glass of water, without chewing, unless otherwise indicated.

Common Drug Classifications & Examples

  • Laxatives: Stimulate intestinal evacuation. Act on the digestive system.
  • Antihypertensives: Reduce blood pressure. Examples include diuretics (which remove fluids), captopril, nifedipine, verapamil.
  • Mucolytics: Reduce mucus viscosity. Act on the respiratory system.
  • Antiemetics: Prevent vomiting. Examples: promethazine, diphenhydramine, fluphenazine, metoclopramide, clebopride, cisapride, trifluoperazine.
  • Anti-inflammatories: Reduce inflammation. Examples: indomethacin, ibuprofen, corticosteroids.

Knowledge Check: True or False?

  1. A tablet can be split and mixed with water. (True – Note: Only if scored or indicated by manufacturer/pharmacist)
  2. Only unconscious people use a nasogastric tube. (False)
  3. Any spoon can be used to measure syrup dosage. (False – Use a calibrated measuring device like a syringe or dosing cup)
  4. An assistant nurse can administer parenteral medication. (False – Typically requires specific qualifications/licensure, varies by jurisdiction)
  5. If a patient is given sublingual administration, they should not swallow the pill. (True)