Rational Drug Use and Pharmacology Guide
Rational Drug Use and Pharmacology
What is Rational Drug Use?
Rational drug use means patients receive medications appropriate to their needs, with the correct dosage based on their individual characteristics, for the appropriate duration. Several factors influence the journey of a drug from development to the pharmacy, including economic conditions.
Drug Development Process
The discovery of new drugs, whether through individual pioneers or pharmaceutical company research programs, begins with targeted searches. New active principles are found in nature or synthesized chemically. Sometimes, drug development involves improving existing drugs. Once an active ingredient is identified, technicians synthesize a substantial amount for testing.
The next step is pre-clinical testing in the laboratory, often using animals. If successful, the technology for industrial-scale production is developed. Then, clinical studies in hospitals are conducted to demonstrate the active ingredient’s safety, effectiveness, and appropriate dosage.
Pharmaceutical Expenditure
Pharmaceutical expenditure refers to the cost of drugs and other pharmaceutical products consumed by a given population. Several payment methods exist:
- Full payment by the state: The state covers the entire cost of the drug or pharmaceutical product, which must be included on a list approved by health authorities, prescribed by healthcare personnel, and acquired through retail pharmacies.
- Copayment: The cost is shared between the state and the patient.
- Full payment by the user: The patient bears the entire cost.
Public pharmaceutical expenditure represents the portion of the retail price covered by public funding, excluding the patient’s copayment. Total pharmaceutical expenditure is the sum of all payments, including full payments by the state, copayments, and full payments by users.
Pharmacology Basics
Pharmacology is the science of drugs. A drug, or active ingredient, is any substance or mixture, natural or synthetic, used in drug development, diagnostics, or to alter a living being’s health.
A medicine is a preparation made from a drug in a specific dosage form intended for curing, alleviating, preventing, or diagnosing diseases. Medicines come in various forms:
- Solid: Granules, tablets, pills, capsules
- Semi-solid: Ointments, salves, lotions
- Liquid: Eye drops, injections, syrups
- Gaseous: Aerosols
Dosage is the amount of drug administered to produce an effect and depends on the patient’s age, weight, and sex. Drug administration routes include:
- Enteral (digestive): Oral or rectal administration, where the drug is absorbed through the gastrointestinal tract and enters the bloodstream.
- Dermal or inhalation: Often used for local effects.
- Parenteral: Subcutaneous, intramuscular, or intravenous administration.
Drug Action and Effects
Drugs work by changing the functions of body cells. This action occurs when the drug interacts with cellular components called receptors, located on the cell surface or inside. The effect is the body’s response to the drug’s action, observable through the senses or simple devices. The effector organ is the organ where the drug’s action occurs. Drug actions can be:
- Stimulating: Increases effector organ function (e.g., caffeine)
- Irritating: Violently stimulates effector organ function (e.g., aspirin)
- Depressing: Decreases effector organ function (e.g., anesthetics)
- Replacing: Provides a secretion missing in the body (e.g., insulin)
- Germicidal: Targets and destroys infectious germs.
Rational Drug Use in Practice
Rational drug use involves selecting medicines based on available scientific information about their pharmacology and evaluating the balance between therapeutic effects and side effects. Medicines can improve life expectancy and quality of life, but problems can arise due to factors such as patient self-medication, patient pressure on doctors for prescriptions, pharmaceutical company promotion campaigns, and inappropriate medication prescriptions. Prescribing a broad-spectrum drug is common practice.