Eyes, CV, & NMJ

Question 1

• *Latanoprost** (Xalatan)
• Bimatoprost* (Lumigan, Latisse)
• Travoprost* (Travatan)
• Unoprostone* (Rescula)

Answer 1

• Agent Type: Prostaglandin Analogues (PGF2α)
• Therapeutic Use (↑↓ Use): Chronic glaucoma. Frontline and increasing usage
• Actions: ↑ aqueous humor outflow; No effect on pupil size or accommodation.
• Adverse: Iris darkening (irreversible), eyelash lengthening & thickening (can be positive effect?,
  Bimatoprost marketed as Latisse), inflammation (eye redness), macular edema.
• Cautions: pts c history of intraocular inflammation (iritis/uveitis), pregnancy (Cat C.)
• Note: Analogues of Prostaglandin F2α

Question 2

• *Timolol** (Timoptic)
• Carteolol* (Ocupress)
• Levobunolol* (Betagan)
• Metipranolol* (OptiPranolol)
• Betaxolol (β1-)* (Betoptic)

Answer 2

• Agent Type: Beta-Adrenergic Blockers- eye
• Therapeutic Use (↑↓ Use): Chronic glaucoma. Frontline but losing ground to prostaglandin analogues (ie. Lanataprost, PGF2α)
• Selectivity: Non-selective: Timolol (gold-std), Levobunolol (longer T½ once/day), Metipranolol, Carteolol (partial agonist, ISA). Beta1-selective: Betaxolol
• Actions: ↓aqueous humor secretion; No effect on pupil size or accommodation.
• Adverse: Low since topical: bronchospasm (less c betaxolol), drowsiness, depression, impotence, hypotension, bradycardia. Stinging, burning feeling.
• Cautions: pts c history of intraocular inflammation (iritis/uveitis), pregnancy (Cat C.)
• Note: asthma, diabetes & thyrotoxicosis (may mask symptoms), HF (cardiac impairment)

Question 3

Succinylcholine (SUX)
(Anectine)

Answer 3

• Agent Type: Neuromuscular Blocking Agents (NMBs) (Depolarizing, non-competitive blocker)
• Therapeutic Use (↑↓ Use): Induction neuromuscular paralysis
• Actions: Agonist. Prototype, non-competitive, depolarizing NMJ blocker (only agent). Rapid onset (1 min), short action (5-10 min), initial fasciculations, then causes paralysis.
• Elimination: Metabolized by pseudoAchE (plasma). Blockade not reversed with AchE inhibition (ie. neostigmine).
• Adverse: Atypical pseudoAchE (prolonged action, 2-3 hr), hyperkalemia (CI: burn or trauma, delayed response >2 day), malignant hyperthermia (usually occurs c halothane, need dantrolene (DOC) for treatment).

Question 4

Tubocurarine

(generic)

Answer 4

• Agent Type: Neuromuscular Blocking Agents (NMBs) (Non-depolarizing, competitive blocker)
• Therapeutic Use (↑↓ Use): Neuromuscular paralysis during surgery
• Actions: Prototype, Long duration (120 min), slow onset, flaccid paralysis, no fasciculations. Some histamine release & ganglia block (together can cause ↓ BP).
• Elimination: liver, kidney or Blockade reversed c AchE inhibition (ie. neostigmine).
• Adverse: Hypotension (histamine release & ganglia blockade), ↑ secretions, bronchospasm.
• Note: Rarely used, better agents available (ie. cisAtracurium).

Question 5

Rocuronium

(Zemuron, Esmeron)

Answer 5

• Agent Type: Neuromuscular Blocking Agents (NMBs) (Non-depolarizing, competitive blocker)
• Therapeutic Use (↑↓ Use): Muscle paralysis, endotracheal intubation
• Actions: Flaccid paralysis, no fasciculation.
• Elimination: Sugammadex selective binding agent to rapidly reverse blockade (not FDA approved). Blockade reversed c AchE inhibition (ie. neostigmine).
• Adverse: Hypotension (histamine release), ↑secretions, bronchospasm (histamine release), depress respiration.
• Note: Fast onset (1-2min), short-intermediate (30-40min); Hypersensitivity, good substitute for succinylcholine

Question 6

cisAtracurium

(Nimbex)

Answer 6

• Agent Type: Neuromuscular Blocking Agents (NMBs) (Non-depolarizing, competitive blocker)
• Therapeutic Use (↑↓ Use): Muscle paralysis, endotracheal intubation
• Actions: Flaccid paralysis, no fasciculation. Some Histamine release.
• Elimination: Spontaneous Hofmann elimination & ester hydrolysis, not organ dependent. Blockade reversed c AchE inhibition (ie. neostigmine).
• Adverse: Hypotension (histamine release), ↑secretions, bronchospasm (histamine release), depress respiration.
• Note: less risk in pts c liver or renal disease.

Question 7

Pancuronium

(Pavulon)

Answer 7

• Agent Type: Neuromuscular Blocking Agents (NMBs) (Non-depolarizing, competitive blocker)
• Therapeutic Use (↑↓ Use): Muscle paralysis, endotracheal intubation
• Actions: Flaccid paralysis, no fasciculation. less histamine release than curare. lack of ganglionic blockade
• Elimination: Blockade reversed c AChE inhibition (ie. neostigmine).
• Adverse: Hypotension (histamine release), ↑ secretions, bronchospasm (histamine release), depress respiration.
• Note: Long-acting & more potent than tubocurarine (x5)

Question 8

Dantrolene

(Dantrium)

Answer 8

• Agent Type: Direct Acting Neuromuscular Relaxant
• Therapeutic Use (↑↓ Use): Treat malignant hyperthermia (DOC). Also, used in stroke, cerebral palsy, multiple sclerosis, muscle spasticity/ rigidity
• Actions: Inhibits Ca2+ release from SR
• Adverse: Significant liver toxicity, muscle weakness
• Note: Other agents used as muscle relaxants (e.g. benzodiazepines).