Pharmacology

Pharmacology: The science of drugs, their physical chemical properties, and effects on the body.

Drug: Any chemical substance absorbed by the body that affects physiological functions.

Pharmaceutical Drug (Medicinal Drug): Chemical substance used to diagnose, cure, treat, or prevent disease. Sources: Plants (Morphine, Quinine), Animals (Fish liver oil), Minerals (Iodine), Bacteria/Fungi (Antibiotics).

Analgesics (Painkillers): Relieve pain (e.g., Aspirin, Paracetamol). Aspirin also reduces fever.

Antibiotics: Kill or inhibit growth of bacteria (e.g., Tetracycline, Cephalosporin).

Sedatives (Tranquilizers): Induce sleep and reduce anxiety (e.g., Diazepam).

Vaccines: Develop immunity against viral/bacterial diseases (e.g., Smallpox, Hepatitis B).

Antiseptics: Applied on skin to kill germs inhibit growth (e.g., Alcohol, Iodine).

Disinfectants: Used on non-living objects to kill germs (e.g., Phenol).

Definition: Drugs that cause dependency (addiction). Body feels needs for them (Withdrawal symptoms).

Types:

• Sedatives: Depress CNS. Slow down brain function. Induce sleep. e.g., Diazepam, Barbiturates.
• Narcotics: Strong painkillers from Opium (Poppy plant). Relief pain & induce sleep. e.g., Morphine, Codeine, Heroin (semi-synthetic).
• Hallucinogens: Cause hallucinations (perceiving things not present). Affect thoughts and emotions. e.g., Mescaline (Cactus), Psilocybin (Mushroom), Marijuana (Cannabis).

Addicts face social stigma, loss of job, crime involvement, and health issues. They become a burden on society. Rehabilitation centers help in recovery.

Definition: Drugs used to treat bacterial infections. First antibiotic: Penicillin (Alexander Fleming, 1928).

Types:

• Bactericidal: Kill bacteria (e.g., Cephalosporins).
• Bacteriostatic: Inhibit growth of bacteria (e.g., Tetracyclines, Sulfonamides).

Groups:

• Cephalosporins: Bactericidal. Stop cell wall synthesis. Treat Pneumonia, Sore throat.
• Tetracyclines: Bacteriostatic. Stop protein synthesis. Treat Respiratory/Urinary tract infections.
• Sulfonamides: Bacteriostatic. Inhibit Folic acid synthesis. Treat Pneumonia, UTI.

Antibiotic Resistance: Ability of bacteria to resist effects of antibiotics due to misuse/overuse.

Definition: Material produced from living organisms that initiates immunity. Derived from 'Vacca' (Cow) - Edward Jenner (1796).

Mechanism: Introduce antigens (weakened/killed germs) -> WBCs produce antibodies -> Memory cells remain in blood -> Faster response upon actual infection.

Types: Killed germs (Polio), Live attenuated (Measles), Toxoids (Tetanus).