intro

• Pharmacology

  The study of how drugs and xenobiotics affect body function and how the body will act on the drug
• Pharmacotherapeutics


  The medical science concerned with the use of drugs in treatment of diseases
• Pharmacy


  The science & profession dealing with the preparation, storage, dispensing & proper utilization of drug products
• Toxicology


  Concerned with harmful effects of chemicals
• Drug


  A substance used as a medicine for treatment of disease, a chemical agent which can affect living processes
• What drugs include

  • Familiar substances e.g. caffeine, alcohol
  • Abused chemicals e.g. cannabis, cocaine
  • Food constituents e.g. vitamins, minerals
  • Cosmetics
• Drugs

  • Has to be absorbed and distributed to get to the site of action
  • Receptors or cellular components at the site of action interact with the drug molecule to give the effect
• Common drug targets

  • Receptors
  • Ion channels
  • Enzymes
  • Transmitters
  • Hormones
• Receptor


  Protein molecules which are normally activated by neurotransmitters/hormones
• Ion channels


  Selective pores in cell membrane that transfer of ions down their electrochemical gradient
• Enzymes


  Catalytic proteins that increase the rate of chemical reactions in the body
• Transmitters


  Chemicals released from nerve terminals
• Hormones


  Chemicals which produce their effects by binding to specific hormone receptors
• Drug sources and preparations

  • Natural & synthetic drugs
  • Pharmaceutical preparations drugs
• Types of pharmaceutical preparations(DONATSS)

  • Tablets /capsules
  • Drug solutions &suspensions
  • Skin patches
  • Aerosols
  • Nasal sprays
  • Ointments /creams
  • Suppositories /pessaries
• Generic name


  Identifies chemical families
• Brand name


  Proprietary (trade) names given by manufacturers
• Drug information sources

  • Drug package inserts / information sheet
  • Reference books(up-to-date): Physicians' Desk Reference(PDR), US Pharmacopoiea, British Pharmacopoiea, British National Formulary, MIMS
• Drug information sheet

  • Tradename
  • Chemical composition
  • Usual dose
  • Contraindications
  • Generic name
  • Chemical strength
  • Indications
  • Side effects
• Classes of drugs

  • Analgesic
  • Anaesthetic
  • Antacid /anti-ulcer
  • Antibiotics
  • Anti-coagulant
  • Anti-convulsant
  • Anti-depressant
  • Anti-diabetic
  • Anti-emetic
  • Anti-histamine
  • Anti-hypertensive
  • Anti-inflammatory
  • Anti-lipidemic
  • Anti-neoplastic
  • Anti-pruritic
  • Anti-pyretic
  • Bronchodilator
  • Decongestant
  • Cathartic
  • Contraceptive
  • Hormone replacement
  • Expectorant
  • Anti-tussive
  • Diuretic
  • Hypnotic or sedative
  • Muscle relaxant
  • Vasoconstrictor
  • Vasodilator
• Routes of drug administration

  • Entereal
  • Parenteral
  • Transdermal
  • Inhalation
  • Topical
• Entereal administration

  • Oral (by mouth)
  • Sublingual (under the tongue)
  • Buccal(between the cheek and gum)
  • Rectal (via rectum)
  • Vaginal (via vagina)
• First-pass effect


  The hepatic metabolism of a pharmacological agent when it is absorbed from the gut and delivered to the liver via the portal circulation
• Rectal route


  • By suppository or enema
  • Advantages: Little or no first pass effect, Used in vomiting/unconscious, Higher concentration rapidly achieved
  • Disadvantages: Inconvenient, Absorption is slow and erratic, Irritation or inflammation of rectal mucosa can occur
• Vaginal route


  • Medication is inserted into the vagina, Administered as a solution, tablet, cream, gel, pessary or ring, The drug is slowly absorbed through the vaginal wall
  • Advantages: Easiest method for treating the specific area
  • Disadvantages: Medications sometimes stain underwear
• Topical dosage forms

  • Creams
  • Ointments
  • Lotions
  • Gels
  • Transdermal patches
  • Disks
  • Solutions
  • Suspensions
  • Sprays
  • Powders
• Topical routes

  • Mucous membrane: Eye drops, Antiseptic creams, Sunscreen, Callous removal, Nasal sprays<br>Skin (dermal): Rubbing in of oil or ointment (local action)<br>Skin (transdermal): Diffusion of drug via the intact skin, Absorption of drug through skin (systemic action)
• Advantages of topical routes

  • Local therapeutic effects
  • Lower risk of side effects - not well absorbed into the deeper layers of the skin or mucous membrane
  • Transdermal: offers steady level of drug in the system, no first-pass metabolism
• Disadvantages of topical routes

  • Transdermal: drug must be potent or patch becomes too large
• pharmacokinetic (ADME)

  • absoprtion
  • distribution
  • metabolism
  • elimination
• pharmacokinetic : mechanism and magnitude of drug effect

  • receptor binding
  • signal transduction
  • physiologic effect