Pharmacokinetics and Pharmacodynamics

Drug Processes and Pharmacology

• Dissociation can occur without forming charged species (ionization).
• Absorption refers to the movement of a drug into the bloodstream.
• Distribution is the transmission of a drug from one location to another in the body.
• Metabolism involves how a drug is processed within the body.
• Excretion is the process of how a drug is expelled from the body.

Therapeutics

• Branch of pharmacology focused on treating diseases, blending pharmacological knowledge with disease understanding to prevent and cure ailments.
• Chemotherapy utilizes chemicals to kill specific harmful cells, particularly microorganisms and cancerous cells, categorized into antibiotics and anti-neoplastic.

Toxicology

• Focuses on the adverse effects drugs may have on the body, including symptoms, mechanisms, treatment, and detection of poisoning.
• The main criterion is the dose; many essential medicines can be toxic in high doses, while some poisons may be therapeutic in low doses.

Rational Prescribing

• Emphasizes the importance of selecting the right medication, dosage, administration route, frequency, and duration for optimal patient care.

Pharmacoeconomics

• A branch of health economics focusing on quantifying the costs and benefits of drugs used therapeutically in economic terms.

Pharmacognosy

• Identification of drugs by visual or olfactory means, now considered a crude and outdated practice.

Regulatory Aspects of Drug Use

• Compassionate Special Permit allows for restricted use of unregistered drugs for serious or life-threatening diseases when no approved treatments are available.
• A patient's physician must agree that the experimental treatment may help, justifying the potential risks involved.

Sources of Drugs

• Plant Sources: Most ancient drugs were derived from plants, including:

  • Digitalis purpurea provides digoxin and digitoxin.
  • Eucalyptus yields essential oil for cough syrups.
  • Atropa belladonna produces atropine.
  • Poppy (Papaver somniferum) gives morphine; Vinca rosea provides vincristine and vinblastine.

• Fruits, Seeds, Elixirs, Syrups, Tinctures:

  • Senna pods yield a purgative effect.
  • Castor oil helps serve as a laxative.
  • Elixirs are flavored preparations containing high alcohol content, e.g., paracetamol elixir.
  • Tinctures involve low concentrations of active ingredients.

• Dosage Forms:

  • Tablets, capsules, pills, powders, granules, suppositories, enemas for various medicinal purposes.

Controversial Issues in Drug Development

• Mistrust of Industry: Concerns over ethical misconduct and profit motives within pharmaceutical companies, affecting public perception.
• Pricing and Profitability: Many health insurers limit coverage for pricey branded drugs, and high costs for innovation hinder accessibility.
• Intellectual Property: Patent protection lasts 20 years, allowing brand-name manufacturers exclusive rights during that period.
• Drug Promotion: Expenditures on drug promotions often surpass R&D costs, leading to aggressive marketing strategies that may compromise physician integrity.

Development Challenges

• Lower-cost testing often occurs outside regulatory environments, causing disparities in drug accessibility for communities involved in development.
• Product liabilities compel companies to extend trials and intensify regulatory reviews, raising consumer drug costs and delaying market entry.
• "Me-Too" drugs represent similar pharmaceuticals aiming to compete with established drugs, raising concerns over genuine innovation versus derivative products.

This quiz covers the processes of absorption, distribution, metabolism, and excretion of drugs in the body, as well as pharmacodynamic concepts like dissociation and ionization.