Anti-Hypertensive Drugs II Flashcards Preview

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Flashcards in Anti-Hypertensive Drugs II Deck (27)
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1
Q

What is Clonidine/Catapres™ (also methyldopa)?

A

Clonidine is a sympatholytic medication used to treat high blood pressure, attention-deficit/hyperactivity disorder, anxiety disorders, withdrawal (from either alcohol, opioids, or smoking), migraine, menopausal flushing, diarrhea, and certain pain conditions. It is classified as a centrally acting α2 adrenergic agonist.

Drug costs $4 (generic) to $37 (branded) to $108 (Catapress™ patches) per month)

2
Q

To what drug class does clonidine belong?

A

Pharmacologic class => central α2 agonist

Therapeutic class–antihypertensive, adjunct to Rx of opioid withdrawal, prophylaxis of migraine

3
Q

Describe the pharmacodynamics of clonidine.

A

Stimulates α2 adrenoceptors in brainstem => down-regulation of sympathetic output

4
Q

Describe the pharmacokinetics of clonidine.

A
  • Onset 1 h, duration 8 h
  • F~85%
  • Also available as cutaneous patch
5
Q

What toxicity is associated with clonidine?

A
  • Withdraw gradually because of risk of rebound HTN
  • Risk of bradycardia in sinus node disease
  • Letharagy, fatigue, depression
6
Q

What interactions should be noted in patients taking clonidine?

A
  • Additive effects with most other antihypertensives

- Additive sedation with other CNS drugs

7
Q

What special considerations should be made for patients on clonidine?

A
  • Pregnancy class C

- Avoid in patients with renal insufficiency

8
Q

What is the route/dose for clonidine?

A
  • Begin with 0.1 mg po bid, up to 1.2 mg per day

- Transdermal begin with 0.1 mg per 24 h as a 7-day patch

9
Q

What should be monitored in patients on clonidine?

A

BP and HR, fatigue

10
Q

What is Trimethaphan/Arfonad™ ?

A

Trimethaphan is a drug that counteracts cholinergic transmission at the ganglion type of nicotinic receptors of the autonomic ganglia => blocks both the sympathetic nervous system and the parasympathetic nervous system.

It acts as a non-depolarizing competitive antagonist at the nicotinic acetylcholine receptor, is short-acting, and is given intravenously ONLY => NOT for long term management of HTN

11
Q

To what drug class does Trimethaphan belong?

A

Pharmacologic class => ganglionic transmission blocker

Therapeutic class => antihypertensive

12
Q

Describe the pharamcodynamics of Trimethaphan.

A
  • Blocks nicotinic transmission within both sympathetic and parasympathetic ganglia (NN receptors)
  • Produces veno- and vaso-dilatation
13
Q

Describe the pharmacokinetics of Trimethaphan.

A
  • Useful only when given iv
  • Produces fall in BP within minutes
  • Partly metabolized, and partly excreted by kidneys
14
Q

What toxicity is associated with Trimethaphan?

A
  • Watch out for sudden, severe drop in BP and HR

- Reduction in just about any sympathetic or parasympathetic response

15
Q

What drug interactions are associated with Trimethaphan?

A

Additive effects with most other anti-hypertensives

16
Q

What special considerations should be accounted for in patients on Trimethaphan?

A
  • Patients are quite miserable, hence only used during general anesthesia
  • Helps to tilt patient to help control BP
17
Q

What are the indications/dose/route for Trimethaphan?

A
  • Given by iv infusion => only to treat HTN crisis or for controlled hypotension during cardiovascular surgery
18
Q

What should be monitored in patients on Trimethaphan?

A

Minute to minute monitoring of BP (and HR)

19
Q

What is Reserpine?

A

Reserpine is an indole alkaloid, antipsychotic and antihypertensive drug, although because of the development of better drugs for these purposes and because of its numerous side-effects, it is rarely used today.

The antihypertensive actions of reserpine are a result of its ability to deplete catecholamines from peripheral sympathetic nerve endings.
- Controls HR, increases contractility and peripheral vascular resistance

  • NOT USED TODAY FOR LONG TERM MANAGEMENT OF HTN
20
Q

What drug class does reserpine belong to?

A

Pharmacologic class => Rauwolfia alkaloid (used to treat HTN)
Therapeutic class => antihypertensive

21
Q

Describe the pharmacodynamics of Reserpine.

A
  • Binds to vesicles that contain NE or serotonin, preventing their uptake, and ultimately depleting the neuron of NE (or serotonin)
  • This effect takes 2-3 weeks to develop, and includes neurons and also the adrenal medulla
22
Q

Describe the pharmacokinetics of Reserpine.

A
  • Good oral bioavailability, but biologic effects take 2-3 weeks to develop (via slow depletion of NE from vesicles)
23
Q

What toxicity is associated with Resperine?

A
  • Dizziness
  • Orthostatic hypotension
  • Depression
24
Q

What interactions should be considered in patients on Reserpine?

A

Additive effects with most other anti-hypertensives

25
Q

When was Reserpine approved by the FDA and what is historically significant about Reserpine?

A
  • Approved by the FDA in 1953
  • First antihypertensive drug approved, and first sympatholytic drug approved by the FDA
  • in 1960’s, drugs included only reserpine, HCTZ, and hydralazine
26
Q

What are the indications/douse/route for Reserpine?

A
  • For HTN

- 0.1-0.2 mg po q day

27
Q

What should be monitored in patients on Reserpine?

A

BP, sympathetic tone, depression