Pharma Principles Flashcards
PHASE I DRUG METABOLISM
non synthetic rxn, drug chemically altered and oxidized
PHASE II DRUG METABOLISM
synthetic rxn, drug conjugated with another moiety
FIRST ORDER ELIMINATION
fraction of drug removed from body is constant and independent of dose.
one half life is 50%, then 75%, 87.5, 93.7, 96.8
ZERO ORDER ELIMINATION
amount of drug removed is constant and dependent on dose, generally d/t key enzyme
CYP 2D6
codeine -> morphine
poor, intermediate, extensive and ultra rapid metabolizers
PM, IM, EM, UM
CYP 3A4
methadone metabolized by CYP 3A4
inhibitors include erythromycin, diltiazem, ketoconozole and saquinavir (increase methadone)
inducers include carbamazepine, phenobarbital, efavirenz, St Johns wort (decrease methadone)
NALBUPHINE, BUTORPHENOL
mixed opioid agonists and antagonists
RECEPTOR TYPES
- ligand gated ion channels
- g protein coupled signalling
- intrinsic enzymatic activity
- nuclear transcription regulating
RECEPTOR DOMAINS
- ligand binding site
- effector/message propagation (signalling) area
DRUGS THAT WORK THROUGH
IONOTROPIC RECEPTORS
nicotine
benzodiazepine
phencyclidine
ketamine
DRUGS THAT WORK THROUGH
G-i0 RECEPTORS
opioids
cannabinoids
γ-hydroxybutyric acid (GHB)
hallucinogens
DRUGS THAT WORK THROUGH
TRANSPORTERS OF BIOGENIC AMINES
cocaine
amphetamine
methamphetamine
NMDA
NMDA receptor antagonists
dissociative, hallucinogenic and euphoric
- ketamine
- dextromethorphan (DXM)
- phencyclidine (PCP)
- methoxetamine (MXE)
- nitrous oxide (N20)
synthetic opioids NMDAR-antagonists
pethidine levorphanol methadone destropropoxyphene tramadol ketobemidone
TOLERANCE
pharmacokinetic pharmacodynamic learned conditioned cross
PHARMACOKINETIC TOLERANCE
increased metabolism, less drug available
PHARMACODYNAMIC TOLERANCE
adaptive changes in receptor density, efficiency of receptor coupling and/or signal transduction
LEARNED TOLERANCE
compensatory mechanisms
CONDITIONED TOLERANCE
subset of learned, when specific cues, such as sights, smells or circumstances, to state of expectation.
CROSS TOLERANCE
tolerance to specific drug in category is generalized to other drugs in same structural/mechanistic category
eg alcohol, benzos and barbiturates
