pharacology (pharmacokinetics, pharmacodynamics, teratogenesis) Flashcards
4 phases of human drug clinical testing?
phase I
- studied in normal volunteers
phase II
i. in target population
ii. vs control drug
phase III
i. like phase 2 but in large groups
ii. vs control drug
phase IV
- post marketing surveillance
what is the definition of bioavailability?
= the amount of drug that reaches the systemic circulation unchanged
what is the definition of volume of distribution (VD)?
= the theoretical volume of water in which the amount of drug would need to be uniformly distributed to produce an observed blood concentration
(fat soluble drugs have huge volumes of distribution and may have prolonged duration of action as they can have a reservoir in fat tissue)
drug elimination - renal and hepatic
p394
factors that may affect need for drug monitoring: (4)
- narrow therapeutic window
- intrinsic toxicity of drug/ how severe SE are
- impaired renal/ hepatic function
- special circumstances affecting pharmacodynamics e.g. breastfeeding, pregnancy, extremes of age
important physiological changes in pregnancy that affect pharmacodynamics: (6)
- increase in circulating volume (40-50%)
- increase renal blood flow and glomerular filtration
- increased 3rd space availability (amniotic fluid and peripheral oedema)
- relatively increased fat content
- reduced albumin and other binding proteins due to overall plasma dilutional effect
- progressive insulin resistance
p 395 –> results of this
drugs that do NOT cross the placenta: (3)
HIT
heparin (unfractioned or LMWH)
insulin
tubocurarine
known teratogens:
“all the As”
- Anticonvulsants
- Antibiotics
- Anticoagulants
- Antimetabolites
- Antipsychotics
- Androgens
- Acne drugs (“A-Vitamin”)
- Alcohol
teratogenic effects of drug according to timing of exposure:
i. <20 days
ii. day 20
iii. day 34
iv. day 36
v. day 42
vi. day 84
i. <20 days –> limb defects
ii. day 20 –> anencephaly
iii. day 34 –> transposition of great vessels
iv. day 36 –> cleft lip
v. day 42 –> VSD, syndactyly
vi. day 84 –> hypospadias
drugs that may result in miscarriage: (4)
MMET
- misoprostol
- mifepristone
- ergotamine
- thrombolytics
FDA pregnancy risk categories
A
- no foetal risk in pregnancy
B
- animal studies have failed to demonstrate a risk to foetus
- no adequate studies in pregnant women
C
- animal studies have shown adverse effects on foetus
- no adequate studies in pregnant pts
- benefit > risk
D
- evidence of risk of human terategenicity
- benefit >risk
X
- evidence of risk of human teratogenicity
- risk >benefit
drugs not excreted in breast (2)
warfarin
aminoglyclasides e.g. gentamycin
AGONISTS
give examples for agonists of following receptors:
i. B1 and B2 adrenergic
ii.a2 adrenergic
iii. a1 adrenergic
iv. muscarinic
v. GABA
vi. u-opiod
vii. dopamine
i. salbutamol
ii. methyldopa
iii. phenylephrine
iv. pilocarpine
v. diazepam
vi. mrophine
vii. cabergoline
ANTAGONISTS
give examples for agonists of following receptors:
i. β1 adrenergic
ii. α1, β1 adrenergic
iii. α1 adrenergic
iv. Muscarinic
v. Histamine (H2)
vi. Testosterone
vii. Dopamine
i. atenolol
ii. labetalol
iii. doxasozin
iv. tolteridone
v. ranitidine
vi. Cyproterone acetate
vii. metoclporamide
examples of drugs that inhibit enzymes.
which enzyme is inhibited by the following drugs?
i. Diclofenac
ii. Ramipril
iii. neostigmine
iv. Zidovudine
v. Acyclovir
vi.Warfarin
vii. Methotrexate
i. COX
ii. ACE
iii. anti-cholinesterase
iv. reverse transcriptase
v.HSV-specific thymidine kinase inhibition
vi. Vitamin K epoxide reductase inhibition
vii. Dihydrofolate reductase inhibition