**Pharmacology**

1. Pharmacology

• Definition: Pharmacology is the study of the interactions between drugs and living systems, including the human body and animals.

• Objectives:

• Understand the mechanisms of drug action on the body.

• Determine the most effective dosage and route of administration.

• Identify and minimize adverse drug effects.

• Develop new drugs that are effective and safe.

2. Drugs

• Definition: A drug is any substance used to prevent, diagnose, treat, or alleviate disease.

• Classification:

• By origin:

• Plants: Morphine, Digitoxin, Atropine, Diosgenin…

• Animals: Insulin, Pantocrin, …

• Minerals: Mercury, gold salts, Kaolin, …

• Semi-synthetic and synthetic: Ampicillin, Aspirin, Paracetamol, …

• By purpose of use:

• Prophylactic drugs: Vaccines, prophylactic antibiotics…

• Therapeutic drugs: Antibiotics, anticancer drugs, painkillers…

• Diagnostic drugs: Contrast agents, dyes…

• By scope of use:

• Prescription drugs: Requires a doctor’s prescription to purchase and use.

• Over-the-counter (OTC) drugs: Can be purchased and used without a prescription.

3. Drug Nomenclature

• Chemical name: Accurately describes the molecular structure of the drug.

• Generic name: The International Nonproprietary Name (INN) of the drug, used worldwide.

• Brand name: The trade name of the drug that was first licensed for marketing, often protected by a patent.

• Generic drug: A drug that has the same active ingredient, strength, and dosage form as the brand-name drug.

• Brand-name drug: A drug that has the same active ingredient, strength, and dosage form as the brand-name drug but is produced by different companies, usually at a lower cost.

Note:

• Drug names can be either generic or brand names.

• It is advisable to use the generic name of the drug to avoid confusion.

• It is advisable to clarify the drug name, strength, and dosage form when purchasing medication.

4. Drug Composition

• Active ingredient: The main component of the drug, which determines its pharmacological effect.

• Excipient: Auxiliary components that help stabilize, preserve, and flavor the drug. They have no pharmacological effect but play an important role in regulating the release rate, absorption, metabolism, etc. of the active ingredient.

• Packaging: Protects the drug from external environmental factors, ensuring the quality and effectiveness of the drug.

Note:

• Packaging plays an important role in drug preservation, especially for injectable drugs and eye drops.

• It is advisable to read the information on the packaging carefully before using the drug.

5. Drug Forms

• Definition: Drug form is the dosage form of the drug, which is the form in which the active ingredient is administered to the body.

• Classification:

• Liquid drugs:

• Solution: The active ingredient is completely dissolved in the solvent. For example: Physiological saline, cough syrup, eye drops…

• Suspension: The active ingredient is not completely dissolved in the solvent, forming a suspension. For example: Milk of magnesia, antibiotic suspension…

• Semi-solid drugs:

• Ointment: The active ingredient is mixed with fat, forming a thick mixture that is insoluble in water. For example: Topical ointment, eye ointment…

• Cream: The active ingredient is mixed with fat and water, forming a smooth mixture that is easily absorbed through the skin. For example: Sunscreen, skin cream…

• Solid drugs:

• Tablet: The active ingredient is compressed into a tablet, easy to store and transport. For example: Aspirin tablets, paracetamol tablets…

• Capsule: The active ingredient is packaged in a capsule, protecting the active ingredient from being degraded by gastric acid. For example: Gelatin capsule, hard capsule…

• Immediate release (IR) drugs: Drugs are released immediately upon entering the body.

• Modified release (MR) drugs: Drugs are released over time, helping to maintain a stable drug concentration in the blood.

Note:

• Drug form affects the rate and extent of absorption of the active ingredient.

• It is advisable to choose a drug form that is appropriate for the patient’s condition and physique.

6. Route of Administration

• Oral:

• Advantages: Safe, convenient, suitable for most patients.

• Disadvantages: Slow absorption, affected by food, may irritate the stomach.

• Injection:

• Advantages: Rapid absorption, high efficacy, suitable for cases requiring rapid action.

• Disadvantages: Painful, infection, risk of anaphylactic shock.

• Eye drop:

• Advantages: Direct action on the eye, easy absorption, few side effects.

• Disadvantages: Drug is easily drained, difficult to adjust dosage.

• Topical:

• Advantages: Direct action on the skin, few side effects.

• Disadvantages: Slow absorption, not as effective.

• Rectal:

• Advantages: Prolonged effect, few side effects.

• Disadvantages: Inconvenient, not suitable for all patients.

Note:

• It is advisable to follow the instructions of your doctor or pharmacist regarding the route of administration.

• Do not change the route of administration without permission.

7. Prescription

• Definition: A prescription is a written document that records the dosage, frequency, route of administration, and duration of drug use prescribed by a doctor for a patient.

• Role:

• Provides accurate drug information to the patient.

• Ensures safety and effectiveness in drug use.

• Has legal and economic value.

• Content:

• Patient’s name, date of birth, gender, address.

• Drug name, strength, dosage form, quantity.

• Instructions for use, duration of use, duration of treatment.

• Doctor’s signature and stamp.

Note:

• It is advisable to keep the prescription carefully.

• Do not use medication based on someone else’s prescription.

8. Pharmacological Studies

• Pharmacodynamics: Studies the mechanisms of drug action on the body.

• Pharmacokinetics: Studies the absorption, distribution, metabolism, and elimination of drugs in the body.

• Chronopharmacology: Studies the effect of biological rhythms on drug efficacy.

• Pharmacogenetics: Studies the influence of genes on drug absorption, metabolism, and elimination.

• Pharmacovigilance: Studies the side effects of drugs in actual use.

9. General Notes

• Medication is a means of supporting treatment, and it cannot completely replace other treatment methods.

• It is advisable to use medication as directed by your doctor or pharmacist.

• Do not self-medicate, especially with prescription drugs.

• It is advisable to inform your doctor or pharmacist about any side effects when using medication.

10. Some Professional Terms

• Brand name/trade name: A specific name given to a product by the drug manufacturing company.

• Brand-name drug: The first drug to be fully licensed for marketing in terms of quality, safety, and effectiveness.

• Generic drug: A drug that has the same active ingredient, strength, and dosage form as the brand-name drug.

This article aims to provide a better understanding of general pharmacology.