Intro Flashcards
Pharm is the study of
Substances that alter bodily functions when introduced into the organism
History of pharm
17th century
18th-20th century
60 yrs ago
Future
17th: Observation and experimentation began to replace theory. Science of drug prep began.
18-20th: Advances in chemistry allowed for understanding of how drugs work.
60 yrs ago: Controlled clinical trials began.
Future: Study genetic makeup and individual response to specific drugs.
True or false. Every drug you recommend will have side effects
TRUE. BUT not every patient will experience every side effect. There is always a little bad to go with the good.
Drug
Any substance that alters body function when introduced into a living organism. Has some effect on a specific target molecule (receptor).
Pharmacodynamics
The actions of a drug on the body. What does the drug do at the receptor?
Pharmacokinetics
The actions of the body on a drug. How the drug moves from site of administration to target and then out of the body. Absorption, metabolism, and excretion
Two types of agonists
Bind to and activates a receptor.
Full: Light switch on or off.
Partial: Dimmer light switch
Two types of antagonists
Prevents other molecules from binding to a receptor- so it cannot be activated.
Reversible or irreversible
Administration
How you give a drug
Absorption
1 body compartment to another.
Pro drug
A drug may reach its intended target as an active molecule or it might require conversion prior to being active. Usually metabolism.
3 steps to pharmacokinetics
Absorption–> Distribution –> Elimination
How can a drug be eliminated after it has an effect?
Metabolism
Kidney (most common)
5 Drug classifications
natural Pure Semi-synthetic Synthetic Biological
6 Drug classifications in terms of therapeutic effect
Anti: Hypertensives Convulsants bacterial Fungal Psychotic Arrhythmics
Drugs have 3 names
- Chemical name.
- Generic name (All drugs only have 1!)
- Brand name. Patented. One drug may have many trade names.
- Patent on a drug lasts how many years
- Trade name lasts for at least
- Time from patenting to marketing takes
- Exclusive rights to sell can be much shorter due to conditions and competition. Often includes the approval time which can be 5 years or more. Average is 11 yrs.
- 50 yrs.
- 8-10 years.
Efficacy
How well it works
Potency
Strength
Selectivity
Side effects
New drugs are developed through these approaches:
- Identification of new drug target.
- Design of new molecule based on understanding of receptor structure
- Screening for biological activity of natural products
- Chemical modification of known molecule. Copy cat
Drug screening
Depends on pharmacologic and therapeutic goal. Tested for other actions, pharmacokinetics, pharmacodynamics, animal studies to determine effect on organ system. All done before human studies.
Modifications may be made as a result Consider interactions with liver enzymes, potential for abuse, other drug interactions.
lead compound
The result of all drug screening procedures.
New command= patent application
Previously known chemical= Use patent
Lead compound moves to Preclinical testing after drug screening. Preclinical testing involves
Toxicity testing.
1. Acute toxicity (lowest dose with no effect and max tolerated dose)
2 Subacute toxicity (Long term- week to month- side effects?)
3. Chronic (Prolonged use)
4. Effect on reproductive organs
5. Carcinogenic
6. Mutagenic
Limitations to preclinical testing
Time consuming.
Large numbers of animals needed
Animal to human toxicity data is not always predictive
Rare adverse effects are likely not to be identified
Human testing is overseen by
The FDA
Clinical trials filed with the FDA is called
Notice of claimed investigational exemption for a new drug (IND). Includes ALLLL info.
Clinical trials phase 1
Healthy volunteers. Small number (20-100) Goal is to determine the safe dose limits.
Absorption, half life and metabolism studied.
Can use on sick individuals IF the drug has significant toxicity.
Clinical trials phase 2
Sick individuals
Small number of patients (100-200)
Determine efficacy- does it even work? WHERE MOST DRUGS FAIL. only 25% get past this.
Clinical trials phase 3
Sick individuals
More patients- thousands
Confirming safety and efficacy
Performed in settings similar to where it’s intended to be used. Ex: Hospitals, clinics.
If drug meets expectations, application is made for permission to market drug
What happens after phase 3 of clinical trials?
Marketing approval. Must submit a new drug application (NDA) with full reports of all preclinical and clinical data Can take months to years to gain approval from FDA.
Once the drug is approved, phase 4 studies begin. What is this?
Physicians using the drug report unknown or surprise side effects. This phase lasts as long as the drug is out.
Monitor safety of it in large number of patients.
What happens when the patent expires?
Any company can produce the drug without paying license fees to the original patent owner. Generic. Can file for an abbreviated new drug application (ANDA)
___% of prescriptions in the US are for generics
67%