Basic Pharm 2 Flashcards
Preg Category A
No risk to animal fetus
No risk to human fetus
Folic acid, B blockers, HIV
Preg Category B1
No Risk to Animal fetus
No human fetus studies done
Preg Category B2
+ risk for Animal fetus
No risk for human fetus
ZIDOVUDINE
Preg Category C1
Risk for animal fetus
No human studies done
Aspirin
Preg Category C2
NO studies done on both animal and human fetus
Preg Category D
Potential risk in both animal and human fetus
Benefits outweight the risk
E.g. Captopril (hypertension in pregnancy)
Preg Category X
Risk in animal and human fetus (teratogens)
X is contraindicated in pregnancy
E.g. Isotretenoin
Administration: Enteral (PO)
Oral, Rectal, and Sublingual
Administration: Parenteral
IV
IM
Subcutaneous
Administration: Other (5)
Topical Transdermal Inhalation Intranasal Suppositories
Absorption: IV
NOT ASSOCIATED TO ABSORPTION
100% of drug reaches circulation, so
100% of drug is available (bioavailability)
Bioavailability
The fraction of administered drug that reaches the systemic circulation in an unchanged form
E.g. If 100 mg of drug is given orally, and 50 mg is absorbed and delivered to systemic circulation unchanged, the bioavailability is 50%
Bioavailability ranges (from greatest to least)
IV > IM > SC > PO > rector (PR) > Inhalation > Transdermal
Which route of administration has significant first pass hepatic metabolism?
Oral , then rectal
What route of administration used for the lack of first-pass effect and for prolonged duration of action?
Transdermal
Absorption determinants (3)
- Solubility (most drugs lipid soluble to diffuse lipid bilayers)
- Concentration Gradient (diffusion down a concentration gradient –> Free, unionized drug
- Surface area and vascularity
the larger the surface area, the better the absorption
the better the vascularity, the better the absorption
What crosses the membrane?
Free, UNIONIZED and the lipid soluble
Passive diffusion
Direction: Down gradient
Energy: No
Carrier: No
Saturable: No
Facilitated diffusion
Direction: Down gradient
Energy: No
Carrier: Yes
Saturable: Yes
E.g. Glucose by GLUT4 transporter
Active transport
Direction: Against gradient
Energy: Yes
Carrier: Yes
Saturable: Yes
P-gp (glycoprotein)
Tricyclic antidepressants
Glucose at intestine (SGLT)
GI absorption: Where are weak acids absorbed?
Stomach
GI Absorption: Where are weak bases absorbed?
Intestine
Drugs that alter gastric pH?
Antacids
Proton pump inhibitors
H2 blockers
