9)Drug characteristics that affect drug actions Flashcards
1
Q
Drug factors
A
Physical properties ⇢ Physical state/Crystal structure/Size of particulate solid drugs ⇢ Determine drugs absorption + bioavailability
2
Q
Physico-chemical properties
A
Lipophilicity, Pk-value + Michealis affinity constant (Km)
- If Km ⇡ = ⇣Affinity of enzyme
- If Km⇣ = ⇡Affinity of enzyme
3
Q
Protein binding
A
Affects the action of the drug
4
Q
Drugs design
A
- For inhalation ⇢ fast absorption
- Liquid forms ⇢ Slower rate of absorption
- Solid drugs ⇢ Slowest rate of absorption
5
Q
hydrophobicity + lipophilic drugs
A
- Limit absorption + lead to low bioavailability
- Too hydrophobic = molecules cannot pass lipid membrane
- Too lipophilic = drug not soluble enough to cross H2O layer adjacent to cell
6
Q
Concentration of drug
A
Affects action of drug
7
Q
Alterations in receptor levels
A
- Beta-blockers ⇢ less effective in elderly patients
- Alpha-blockers ⇢ resulting in orthostatic hypotension
- Elderly ⇢ at more risk of adverse drug reactions due to change in sensitivity
- CNS depressants ⇢ may result in delirium, confusion, agitation + sedation
8
Q
Molecular structure + functional groups
A
can modify pharmacological activity
9
Q
Polypharmacy
A
treatment w/multiple medications for different conditions + symptoms
also includes:
- Excessive meds
- Unecessary meds
- These place patient at risk of adverse drug reactions
10
Q
Dose of drug
A
amount of drug administred will have a direct impact on effect
- Dosis minima = lowest dose
- Dosis optima = optimal therapeutic dose
- Dosis maxima = max daily dose
- Dosis toxica = toxic doe
- Dosis letais = lethal dose
11
Q
Drug therapy during pregnancy
A
- Drugs can pass through lactation into breast milk + can affect infant
- Lipid soluble drugs = higher concentrations in milk
- Generally most drugs are too low in concentration to be harmful to an infant
