Anti-Hypertensive Drugs II Flashcards Preview

Pharm Block 1 > Anti-Hypertensive Drugs II > Flashcards

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

What is Clonidine/Catapres™ (also methyldopa)?

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

To what drug class does clonidine belong?

Pharmacologic class => central α2 agonist

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

3

Describe the pharmacodynamics of clonidine.

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

4

Describe the pharmacokinetics of clonidine.

- Onset 1 h, duration 8 h
- F~85%
- Also available as cutaneous patch

5

What toxicity is associated with clonidine?

- Withdraw gradually because of risk of rebound HTN
- Risk of bradycardia in sinus node disease
- Letharagy, fatigue, depression

6

What interactions should be noted in patients taking clonidine?

- Additive effects with most other antihypertensives
- Additive sedation with other CNS drugs

7

What special considerations should be made for patients on clonidine?

- Pregnancy class C
- Avoid in patients with renal insufficiency

8

What is the route/dose for clonidine?

- 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

What should be monitored in patients on clonidine?

BP and HR, fatigue

10

What is Trimethaphan/Arfonad™ ?

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

To what drug class does Trimethaphan belong?

Pharmacologic class => ganglionic transmission blocker

Therapeutic class => antihypertensive

12

Describe the pharamcodynamics of Trimethaphan.

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

13

Describe the pharmacokinetics of Trimethaphan.

- Useful only when given iv
- Produces fall in BP within minutes
- Partly metabolized, and partly excreted by kidneys

14

What toxicity is associated with Trimethaphan?

- Watch out for sudden, severe drop in BP and HR
- Reduction in just about any sympathetic or parasympathetic response

15

What drug interactions are associated with Trimethaphan?

Additive effects with most other anti-hypertensives

16

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

- Patients are quite miserable, hence only used during general anesthesia
- Helps to tilt patient to help control BP

17

What are the indications/dose/route for Trimethaphan?

- Given by iv infusion => only to treat HTN crisis or for controlled hypotension during cardiovascular surgery

18

What should be monitored in patients on Trimethaphan?

Minute to minute monitoring of BP (and HR)

19

What is Reserpine?

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

What drug class does reserpine belong to?

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

21

Describe the pharmacodynamics of Reserpine.

- 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

Describe the pharmacokinetics of Reserpine.

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

23

What toxicity is associated with Resperine?

- Dizziness
- Orthostatic hypotension
- Depression

24

What interactions should be considered in patients on Reserpine?

Additive effects with most other anti-hypertensives

25

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

- 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

What are the indications/douse/route for Reserpine?

-For HTN
-0.1-0.2 mg po q day

27

What should be monitored in patients on Reserpine?

BP, sympathetic tone, depression