Introduction to Pharmacology

Pharmacology

The branch of medicine concerned with the uses, effects and modes of action of drugs on living tissues.

Drug

A substance that modifies the activity of living tissue, interfering with either normal or abnormal physiology.

Physiology

The science of how living tissues function, including both normal and abnormal physiology (pathophysiology).

Therapeutics

The study of the use of pharmacological agents in disease states, typically following a medical diagnosis

Pathology

The study of how the body goes wrong in disease states, including the causes and effects of disease and injury.

Agonist

A drug or natural body substance that directly causes a measurable response, which can be excitatory or inhibitory depending on the receptor activated.

Antagonist

counteracts the action of an agonist by acting on the same receptor type, typically with higher affinity for the receptor

EC50 value

The concentration of a drug at 50% of its maximum effective concentration, used to measure the potency of a drug.

Competitive antagonism

When drugs compete to bind the same receptor. Agonist concentration-response curve shifts. Linear relationship between agonist and antagonist concentrations

Irreversible-competitive antagonism

When the bond between an antagonist and receptor is so strong that increasing agonist concentration doesn't displace the antagonist.

Non-competitive antagonists

Antagonists that act at sites other than the agonist binding site.

Toxicology

The study of the toxic effects of drugs and environmental hazards, including the capacity of drugs to produce disease or abnormalities.

Iatrogenicity

drugs producing disease from side effects or inappropriate prescribing eg anti-malarial drug mefloquine → profound suicidal thoughts

Teratogenicity

The capacity of drugs to produce abnormalities in the unborn foetus or child

Thalidomide

A drug that caused severe birth defects (phocomelia) when prescribed for severe morning sickness in the late 1950s due to its teratogenic properties.

Botulism

muscle paralysis, respiratory failure, and potentially death caused by toxins of Clostridium botulinum

In vivo

A method of studying drugs using living organisms.

Ex vivo

Studying drugs using tissue samples. Closer to physiological relevance than isolated cells.

High throughput screening

A method used by drug companies to screen thousands of compounds each day using cell lines to observe their pharmacological properties

Drug targets

Specific molecules or receptors in the body that drugs interact with, including ion channels, enzymes, transporter/carrier proteins, and receptors.

botulinum as a therapeutic is used to treat

• facial wrinkles

• severe underarm sweating

• cervical distonia

• blepharospasm

• strabismus

cervical distonia

neurological condition which causes severe neck and shoulder muscle contractions

blepharospasm

uncontrollable blinking

strabismus

misaligned eyes

what causes severe underarm sweating?

ACh from muscarinic receptors

Clostridium botulinum structure

Gram-positive, anaerobic, rod shaped, spore-forming

Paul Ehrlich, 1909

discovered anti-microbial chemotherapy, the treatment of syphilis with arsenical compounds

William Blair-Bell

treated breast cancer with lead colloidal mixtures