Succinylcholine (depolarizing muscle relaxant)

• depolarizing muscle relaxant
• broken down by a pseudocholinesterase enzyme
• short duration of action b/c of rapid clearance
• 1 out of 3000 people do not have pseudocholinesterase enzyme and if you give this to these patients it will last much longer (6-12 hours rather than 5-10 min) b/c clearance is greatly reduced in patients without the enzyme
• This is a pharmacogenetic difference in how patients will respond to the drug
• It can trigger malignant hyperthermia (MH)

NDMR (non-depolarizing muscle relaxant)

1. benzylisoquinoline

• cisatracurium

• unique metabolism (Hoffman degredation)
• after administration, temp and pH changes cause spontaneous breakdown
• good for patients with abnormal liver or renal functions that may have trouble metabolizing other NDMRs
• good for long-term administration b/c it does not cause steroid-related side effects in chronically ventilated patients that may occur with other NDMRs

NDMR (non-depolarizing muscle relaxant)

1. Aminosteroid ("curonium")

• Pancuronium
• Vecuronium
• Rocuronium

Pancuronium:

• long-acting
• renally cleared
• anticholinergic/antimuscarinic properties (increases HR)

Vecuronium/Rocuronium:

• intermediate acting

1. What is a belladonna alkaloid?

2. Where does the term belladonna come from?

1. Group of alkaloids found in plants such as belladonna and jimsonweed. Use to:

• dilate pupils of the eye
• dry respiratory passages
• prevent motion sickness
• relieve cramping of intestines/bladder
• Atropine and Scopolamine

2. Belladonna is a italian/Spanish term meaning "beautiful woman." The original discoverers used the plant to dilate the eyes of women so they would look (what was perceived as) "more beautiful."

What are the similarities and differences of:

1. Atropine
2. Scopolamine
3. Glycopyrrolate
4. Ipratropium

Similarities:

• Antimuscarinics used to: dry secretions, increase HR, and dilate bronchioles/pupils
• Have affinity for the receptor but no intrinsic activity (occupy the receptor but do not produce any effects by keeping Ach from binding to the receptor)

Atropine:

* binds competatively with Ach

* works centrally and peripherally

* small doses: cause HR to decrease d/t blockade of M-1 receptors on presynaptic ganglion

• large doses: M-2 receptors on the SA node are blocked and HR increases

Scopalamine:

1. works much like atropine but with greater action on the CNS

• longer duration causing more sedation and antisalagogue effect
• used as an anti-motion sickness drug

Ipratropium:

• derivative of atropine used to treat asthma/COPD in those unable to take adrenergic agonists
• inhalation, does not enter systemic circulation

Glycopyralate:

• used in anesthesia for anticholinergic effects
• used to increase HR

1. Summarize the pharmacology of nicotine.

2. Discuss effects of low and high doses and include information from pages 118-119

Low Doses: ganglionic stiumulation by depolarization

High Doses: nicotine causes ganglionic blockade