• Pharmacology

    Pharmacodynamics

    Pharmacodynamics Pharmacodynamics is derived from the Greek word i.e. “Pharmacon” means Drugs and “Dynamics” means Action. It is the study of biochemical and physiological effects of drug and their mechanism of action at the organ level and cellular level. “What the drugs do to the body when they administered”. Site of drugs action Extracellular Cellular Intracellular Principle/types of drugs action Stimulation The enhancement of the activity of specialized cells. Example: Adrenaline stimulates the heart, pilocarpine stimulates salivary glands. Excessive stimulation is often followed by depression of that function. For example, a high dose of picrotoxin (CNS stimulant) produces convulsions followed by coma and respiratory depression. Depression The specialized cells selectively…

  • Pharmacology

    Eicosanoids (Prostaglandins)

    Eicosanoids Prostaglandin (PGs) and leukotrienes (LTs) are derived from polyunsaturated essential fatty acids with 20 carbon atoms. 1930: Human semen – contracts uterus and other smooth muscles (SM) to cause fall in BP. The prostaglandin was derived from the prostate. 1970: Aspirin like drugs inhibit PG synthesis Thromboxanes (TX) and Prostacyclin (PGI) Bergstrom, Samuelsson and Vane got the Nobel Prize in 1982 for their work on PGs and LTs. Chemistry Chemically, PGs may be considered to be derivatives of prostanoic acid, though prostanoic acid does not naturally occur in the body. PGs are designated in series as – A, B, C ….I etc. depending on ring structure and substitution Each…

  • Pharmacology

    Autacoid (5-hydroxytryptamine (5-HT, serotonin))

    5-hydroxytryptamine (5-HT, serotonin) Serotonin and enteramine both are 5-hydroxytryptamine, a monoamine neurotransmitter, and are derived from tryptophan. About 90% of the body contains 5-HT is localized in the intestine and the rest are in platelets and the brain. It also found in other animals and plants; Animals: invertebrates and mollusks, arthropods, snake and bee venom/sting. Plants: plants: tomato, pear, banana & pineapple. Synthesis storage and destruction It is synthesized from the amino acid tryptophan. Tryptophan converted to 5-hydroxytryptophan with the help of enzyme hydroxylase. 5-HTP decarboxylase to produce 5-HT. The decarboxylase is non-specific, acts on DOPA as well as 5-hydroxytryptophan (5-HTP) to produce DA and 5-HT respectively. It is degraded…

  • Pharmacology

    Chemotherapy of Malignancy

    Cancer   Cancer is uncontrolled proliferation and abnormal multiplication of cells within the body. A mass of tissue formed as a results of; Abnormal Excessive Uncoordinated Autonomous and purposeless Proliferation of cells The Cell Cycle Malignant cells go through normal mitosis but synthesize DNA and divide at a faster rate Most chemo drugs exert antineoplastic effects during DNA synthesis (S-phase) or mitosis [Cell Cycle Specific (CCS) drugs]. Other chemo drugs sterilize tumor cells whether they are cycling or resting in the Go compartment [Cell Cycle Non-Specific (CCNS)] Possible signs and symptoms Lump. Abnormal bleeding. Prolonged cough. Unexplained weight loss. Change in bowel movement. Weight loss Types of Cancer Types of…

  • Pharmacology

    Emetic and anti-emetics

    Emetic and anti-emetics Nausea and vomiting are basic human protective reflexes against the absorption of toxic, as well as responses to certain stimuli. Nausea: coming from two Greek words “Nautia” means sickness and “Vomere” means discharge. Nausea is define as a subjectively discomfort or unpleasant wavy like sensation in the back of the throat or epigastrium. Effect may shows flushing, tachycardia, sweating, excess salivation and sensation of being cold or hot may occur. Vomiting or emesis is characterized by contraction of the abdominal muscle, descent of diaphragm and opening of gastric cardia, resulting in forceful expulsion of stomach contents from the mouth. Pathophysiology Complex interaction between central and peripheral pathway:…

  • Pharmacology

    Adrenergic Agonist

    Adrenergic system The adrenergic drugs are activate the adrenergic receptor or adrenoreceptor by stimulating nor epinephrine (Nor adrenaline) or Epinephrine (Adrenaline). It is also known as sympathomimetic. The drugs that are blocks the activation of adrenergic receptor are named as sympatholytic. The sympathomimetic acts on adrenergic receptor either directly (Direct-acting-agonist) or indirectly (Indirect-acting-agonist) by enhance release or blocking reuptake of NE (Indirect -acting-antagonist). Direct acting agents Indirect acting agents Direct and indirect acting (Mixed action agents) AlbuterolClonidine DobutamineDopamine Epinephrine Formeterol FenoldopamIsoproterenol Mirabegron Norepinephrine Phenylephrine Terbutaline   AmphetamineCocaine Ephedrine Pseudoephedrine Mechanism of adrenergic agonist A. Adrenergic transmission i. Synthesis of CAs ii. Storage of CAs iii. Release of CAs iv. Binding…

  • Pharmacology

    Anticholinergic drug

    Anticholinergic drug Anticholinergics are those antagonize the effect of neurotransmitter (Ach) on autonomic effectors and in the CNS. Classification Natural alkaloid e.g. Atropine, Hyoscine (Scopolamine) Semisynthetic derivatives e.g. Homatropine, Atropine Methonitrate, Hyoscine butyl bromide, Ipratropium bromide, Tiotropium bromide Synthetic derivatives A. Mydriatics: e.g. Cyclopentolate, Tropicamide B. Quaternary Compound: e.g. Propantheline, Oxyphenonium, Clidinum, Pipenzolate, Methylbromide, Isopropamide, Glycopyrolate. C. Tertiary amine: e.g. Dicyclomine, Valethamate, Pirenzepine. D. Vasicoselective: e.g. Oxybutynin, Flavoxate, Tolterodine. E. Anti-parkinsonian: e.g. Bipiridine, Procyclidine, Trihexyphenidyl (Benzhexol) Mechanism of action Anticholinergics are the class of drugs that blocks the neurotransmitter (Ach) in CNS and PNS. It combine reversibly with muscarinic cholinergic receptor thus preventing access of neurotransmitter (Ach) in these sites.…

  • Pharmacology

    Anti-Tubercular drugs

    Anti-Tubercular drugs Tuberculosis is a granulomatous disease and a major health problem in developing countries. About 1/3rd of the world’s population is infected with tuberculosis. The causative organism Mycobacterium tuberculosis. Classification First line drugs It has high anti-tubercular efficacy as well as low toxicity. Example: Isoniazid (H) Rifampicin (R) Pyrazinamide (Z) Ethambutol (E) Streptomycin (S) Second line drugs These drugs have either low anti-tubercular efficacy or higher toxicity or both and are used in special circumstances only. Ethionamide (Eto) Prothionamide (Pto) Cycloserine (Cs) Para amino salicylic acid (PAS) Rifabutin Terizidone Thiacetazone (Thz) Fluoroquinolones Ofloxacin (Ofx) Levofloxacin (Lvx or Lfx) Moxifloxacin (Mfx) Ciprofloxacin (Cfx) Injectable Kanamycin (Km) Amikacin (Am) Capreomycin (Cm)…

  • Pharmacology

    Neurohumoral Transmission & Cholinergic Drugs

    Nervous System Network of nerve cells and fibres which transmits nerve impulse between parts of the body. Classification of nervous system Motor: carry neuronal impulse away from CNS to different parts. Sensory: Carry impulse from sensory stimuli towards the CNS and Brain. Sympathetic Parasympathetic Fight or flight condition.Increase BP, HR, Glucose, perfusion to skeletal muscle, mydriasis, Bronchodilator. Rest and digest Miosis Decrease HR, BP, Bronchial secretion, Insulin release, Digestion, excretion Introduction to Autonomic Nervous System Drugs Neurohumoral transmission Neurohumoral transmission implies that nerves transmit their message across synapses and neuroeffector junctions by the release of humoral (Chemical) message. Steps in Neurohumoral transmission Impulse conduction Resting transmembrane potential -70mv (inside) (High…

  • Pharmacology

    Autacoid – Histamine & Anti-histamine

    Definition Autacoid is derived from two word Autos means “Self” and Akos means “healing substance”. Autacoids are the biological substance that release from the cell is response to variety of stimuli to produce physiological and pathological responses locally. A hormone called local hormone that are produced by specific cells, and transported through circulation to act on target tissue. Classification of Autacoid Amine Autacoids Histamine, 5HT (Serotonin) Lipid derivatives autacoids Prostaglandin, leukotriene, platelet activating factor Peptide autacoids Plasmakinins (Bradykinin), angiotensin Histamine Histamine is an organic nitrate compound (Formed from amino acid histidine), which is involved in: Immune response (allergic and immune response) Resulting physiological function Acting as a neurotransmitter It is…

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