• The word Pharmacology is derived from Greek word Pharmakon which means Drug and Logos which means to study.
• Pharmacology is the branch of Medicine which deal with study about the drug.
• The German pharmacologist Oswald Schmiedeberg is known as the Father of Pharmacology.
• Ramnath Chopra is known as Father of Indian Pharmacology.
•. Two mail division of pharmacology
A. Pharmacodynamics – (dynamic – Power)
• What the drug does to the body.
B. Pharmacokinetics – (kinesis – Movement)
• What the body does to drug
• Excretion
• Absorption
• Distribution
• Metabolism
• Drug – Drug is any substance which can alter the normal physiology of the living cell.
• Drug may have positive or negative effect on Patients.
Ex – Heroin is a drug.
• Medicine – Any substance which is used to prevent or cure a symptoms or diseases.
• Medicine is producing a positive effect on Patients.
• All medicine, all drugs, whereas not all drugs are medicine.
• Pharmacovigilance – Vigilance — side effects
• Study about the side effects of the drug.
• Also known as drug safety.
• Pharmacopoeia – It is a book containing a list of drugs with their effects and direction for their use.
Ex – USP – United States Pharmacopoeia.
IP – Indian Pharmacopoeia.
• Pharmacotherapeutics – It is the study of the therapeutic uses and effects of the drugs.
• Clinical Pharmacology – Scientific study of drug in men.
• Pharmaceutics – Manufacturing of the drugs.
• Toxicology – It is the study of poisonous effects of the drugs and other chemicals.
• First Pass Metabolism – The amount of drugs which destroyed by liver before reaching to systemic circulation.
• Bioavailability – Amount of the drug which present in the systemic circulation dose is known as bioequilant.
• T ½ or half-life of drugs – Time taken for its plasma concentration to be reduced to half of its original value.
• Loading dose – Amount of the drug given in the beginning to achieve target concentration quickly/Rapidly.
• Maintenance dose – Amount of the drug given to maintain the target plasma concentration.
• Therapeutic dose – Amount of the drug to produce therapeutic. Ex.-Lithium-0.8-1.2 mg/dl.
• Essential drug – Drugs Which easily accessible and available. EX-PCM.
• Potency of drug – Amount of the drug Which able to produce therapeutic effects.
• Efficiency of drug – Max effect of drug.
• Drug Effect —
1. Desire effect/therapeutic effect
• PCM – Antipyretic.
• Atropine – Decrease oral selection.
2. Undesired effect/non therapeutic effect
• Predictable – Side effects. Atropine — Dry mouth.
• Unpredictable–Adverse effects. PCM – Liver damage.
• Secondary effects – These are indirect consequence of primary action of the drug.
Ex – Corticosteroid cause weak host defense mechanism so that latent tuberculosis gets activated.
• Toxic effects – these are excessive pharmacological action of the drug to overdose or prolonged use of drug.
Overdose may be
– Absolute(Accidental, Suicidal)
– Relative( use of gentamycin in renal failure)
– Toxicity may result from increase of the therapeutic effects itself.
Ex – Bleeding due to heparin use
– Coma due to heparin use
• Idiosyncrasy – It is genetic determined abnormal reactivity to drug.
Ex – Barbiturate cause excitement in some individual.
• Drug allergy – It is an immunologically mediated reaction producing stereotype Which unrelated to drug profile.
• Photo sensitivity – It is a skin reaction resulting from drug induced sensitization of the skin to UV radiation.
A. Phototoxic — Drug accumulate in the skin absorbs light and undergoes a photo chemical Reaction local tissue damage that is erythema, Edema, blistering.
-More common fluroquinolons, sulfonamides.
B. Photo allergic – drug induce a cell mediated immune response which on exposure to light produce popular or eczematous contact dermatitis.
– chloroquine, chlorpromazine.
• Teratogenicity – It refer to capacity of a drug to cause fetal abnormalities to a pregnant woman.
Ex – Lithium
• Drug induced disease/Iatrogenic effects – It is functional disturbance caused by drug which persist even after the drug has been withdrawn.
Ex – Peptic ulcer — corticosteroid.
• Pharmacodynamic – Study about the effect of drug on body.
