Flashcards in Drug Discovery and Development Deck (13):
What is the typical drug development timeline?
Preclinical studies (animal)
-- [Regulatory Review: request to do on humans] --
Clinical Testing (phase 1, 2, 3)
-- [Regulatory Review: request to market drug] --
Post-Marketing Studies (phase 4)
What are two examples of drug-drug interactions that have been withdrawn from the market?
1. Sorivudine: Antiviral, stopped 5-fluorouracil metabolism (15 deaths in Japan)
2. Terfenidine: antihistamine when with ketoconazole. Leads to cardiotoxicity
What are two examples of unexpected toxicity reactions that caused the drugs to be withdrawn from the market?
1. Troglitazone: for non-insulin dependent diabetes (severe hepatotoxicity)
2. Rofecoxib: selective COX-2 inhibitor for chronic pain relief. (Increased heart attack and stroke).
What are the two main reasons for failure during drug development?
1. Inappropriate pharmacokinetics
2. Lack of efficacy
What are the 6 ways a drug may be discovered?
1. From herbal/traditional remedies
2. Empirical Approach
3. Rational Drug design
4. Prodrugs/analogs/metabolites of existing drugs
5. Serendipity-chance observation
What are 3 example s of herbal remedies?
Morphine (Opium poppy)
Salicylic acid (willow bark)
What are anti-cancer drugs and Cyclosporin (an immunosuppressant) an example of?
An empirical approach to drug discovery.
Describe what rational drug design involves.
Understanding the cellular/molecular basis of diseases then using computer technology to determine 3D structure of receptor to design agonist drug.
E.G: Propranolol (beta-blocker), Cimetidine (Hydrogen-antagonist)
What is aspirin and paracetamol an example of?
Prodrug. Aspirin is salicylic acid with an acetyl group (or else it is a gut irritant). Paracetamol is a derivative of phenacetin which is an irritant to the kidneys.
Describe serendipiity drug development.
By chance observation.
Penicillin, valproate, sildenafil (viagra)
Describe the 2 main phases of a drug development process.
- animal studies
- Phases 1-4
In pre-clinical studies, what is assessed?
Pharmacology, ADME, toxicology.
Then using this info, does the drug need to be re-designed?