Test 2 Lectures 2-4 Flashcards Preview

Pharm > Test 2 Lectures 2-4 > Flashcards

Flashcards in Test 2 Lectures 2-4 Deck (80)
Loading flashcards...
31

What are the BP effects of epi at LOW doses? (explain)

What are the BP effects of epi at HIGH doses? (explain)

- Epi has higher affinity for beta2 relaxing receptors (vs. alpha1 constrictors)
- Therefore, TPR slightly decreases at low dose, decreasing BP

- At high dose, there is still some beta2 receptor binding, but there are way more alpha1 (and alpha2) receptors
- Leads to robust increase in TPR and hence, BP

32

What are the CO effects of epi at low and high doses? (explain)

- Low dose: although TPR slightly decreases, increased Na+ (funny) and L-type Ca2+ channel release leads to increased Beta1 activation, increased chronotropy, as well as inotropy, leading to increased CO

- High dose: further increase BP (due to alpha1/2 activation) leads to further increase in CO thru same mech as above

33

Briefly state the bronchiolar effects of epi and what receptor they are due to.

1. Bronchodilation (beta2)
2. Decreased bronchial secretions (alpha1)

34

Toxic effects of epi? (1)

Arrhythmia

35

Therapeutic uses of epi? (3)

- Anaphylaxis
- Cardiac arrest
- Bronchospasm

36

What adrenergic receptors does NE have affinity for?

Alpha1, alpha2, beta1

37

Is NE's half-life long or short? How is it therefore administered?

- Short half-life
- Give by controlled infusion.

38

Explain the CV effects of NE.

- Primarily alpha1 receptor activation, leading to vasoconstriction and increased TPR (*more than w/epi because there is no vasodilating beta2 activation)
- Also inotropic and chronotropic effects due to beta1 activation
- Large increase in TPR leads to baroreceptor reflex (sinuses) that slows HR, but still overall increase in MAP

39

Toxicity of NE? (1)

Arrhythmia

40

Therapeutic use of NE? (1)

Vasodilatory shock

41

Contraindications of NE? (1)

Pre-existing ischemia

42

What receptors does DA bind?

(Looks like NE, but also binds its own receptors)
- D1, D2, alpha1, alpha2, beta1

43

Explain the physiological effects of DA at low, medium, and higher doses.

- Low: D1 activated, decrease in TPR
- Medium: Beta1 activated, increased contractility and HR
- High: Alpha receptors activated, further increasing BP and TPR

44

Dopamine:
Toxicity, therapeutic uses, and contraindications?

- Tox: hypotension (at low infusion rates), ischemia (at high infusion rates)
- Uses: Cardiogenic shock
- Contra: Tachyarrhythmias

45

What drug category is isoproterenol?
What degrades it?
Explain its effects.

- Non-selective beta-adrenergic agonist
- COMT

- Peripheral vasodilation (beta2), diastolic
- Transient increase in systolic BP due to positive inotropy and chronotropy (beta1, but offset by beta2 effects above)
- Bronchodilation (beta2)

46

Isoproterenol:
Toxicity, therapeutic uses, and contraindications?

- Tox: Tachyarrhythmias
- Uses: not often used
- Angina w/arrhythmias

47

What drug category is Dobutamine?
What degrades it?

Explain its effects.

- Selective beta1-adrenergic receptor agonist
- Rapidly degraded by COMT, must be infused

- Increased CO

48

Dobutamine:
Toxicity and therapeutic uses? (no contraindications)
Relative 1/2-life?

- Tox: hypotension
- Uses: short-term tx for CHF (1/2-life 2-3 min) or cardiogenic shock

49

What drug category are terbutaline and albuterol?
Explain their effects.

- Selective beta2-adrenergic agonists

- Bronchodilation (+ uterine relaxation in late pregnancy)

50

Terbutaline and albuterol:
Toxicity and therapeutic uses? (no contraindications)

- Tox: tachycardia (B1), muscle tremor (B2), tolerance (B2)
- Uses: bronchospams, chronic obstructive airway dz tx

51

What drug category is phenylephrine?
Explain its effects.
1/2-life?

- Selective alpha1-adrenergic agonist

- Increase TPR and BP
- Baroreceptor reflex decreases HR
- Dilates pupils
- Decreased bronchial and upper airway secretions

- 1/2-life less than 1 hr

52

Phenylephrine:
Toxicity, therapeutic uses, and contraindications?

- Tox: HTN
- Uses: Paroxysmal SVT, mydriatic agent, nasal decongestant (constricts leaky sinuses)
- Contra: HTN, V-tac

53

What drug category is clonidine?
Explain its effects.

- Selective alpha2-adrenergic agonist

- Peripherally, clonidine causes mild vasoconstriction and slight increase in BP
- Crosses BBB to cause reduced symp outflow, reducing vasoconstriction and BP

54

Clonidine:
Toxicity and therapeutic uses? (no contraindications)

- Tox: Dry mouth, hypertensive crisis (following acute withdrawal due to symp sensitization from the inhibition)
- Uses: HTN (when due to symp activation)

55

What are the 2 classes of indirect sympathomimetics?

1. Releasing agents
2. Reuptake blockers

56

Name the 6 indirect sympathomimetic drugs that are known as "releasing agents"

- Amphetamine
- Methamphetamine
- Methylphenidate
- Ephedrine
- Pseudoephedrine
- Tyramine (in food)

57

Recall: when does tyramine cause its damaging effects?
(How long is it's 1/2-life?)

Highly susceptible to degradation (Very short 1/2-life) by MAO and thus has little effect unless pt is taking MAO inhibitor (then NE builds up)

58

How do the 6 amphetamine-like drugs (releasing agents) work?

Amphetamine-like drugs are taken up by re-uptake proteins and subsequently cause reversal of the re-uptake mechanism resulting in release of NT in a Ca2+ independent manner.

(amphetamines P'late transpoter)

59

What are the CV effects of amphetamine, methamphetamine, methylphenidate,
ephedrine, pseudoephedrine, and tyramine?

- Increased TPR and diastolic BP (alphas)
- Positive inotropic and chronic tropic effects (beta1), increase systolic BP
- CNS: stimulant + anorexia

60

Amphetamine, methamphetamine, methylphenidate, ephedrine, pseudoephedrine, and tyramine:
Toxicity, therapeutic uses, and contraindications?

- Tox: Tachycardia (B1)
- Uses: ADHD, narcolepsy, nasal congestion (pseudoephedrine in sudafed)
- Contra: Tx w/MAOI in past 2 weeks