[23] Pharmacology I Flashcards
When should you administer the first dose of Alpha-1 Blockers? Is it a large or small dose?
Small dose administration at bedtime
Function: Guanethidine
Inhibit Ca2+ dependent release of NE
Function: Reserpine
Blocks vesicles to take up and store biogenic amines
Examples of Alpha-2 Agonist Specific Receptors
Clonidine
Methyldopa
Onset of Action of Furosemide
Oral
IV
O: 2 hours
IV: 20 minutes
Effects of Furosemide Toxicity
Ototoxicity Hypokalemia Dehydration Allergy Nephritis Gout
“OH DANG”
Drugs that cause “First-Dose” Phenomenon
Alpha-1 Selective Blockers
For patients with BPH and HPN what drug should you give?
Alpha-1 Selective Blockers
Hexamethonium toxicity causes?
- Excessive orthostatic hypotension
- Sexual dysfunction
- Constipation
- Urinary retention
- Precipitation of Glaucoma
- Blurry Vision
- Dry Mouth
Hexamethonium Mechanism of Action
Blocks nicotinic cholinoceptors on both sympathetic and parasympathetic ganglia
This drug causes Lupus-like syndrome in cases of toxicity
Hydralazine
Hydralazine’s Mechanism of Action
Causes Nitric Oxide release and subsequent vasodilation
This drug causes hirsutism in cases of toxicity
Minoxidil
This drug is known to cause reflex tachycardia
Minoxidil
This drug is a potassium sparing diuretic
Spironolactone
Mechanism of Action of Spironolactone
Aldosterone Antagonist
Pharmacokinetics of Digoxin:
- % Bioavailability
- % Protein Bound
- Half Life
- Does it undergo enterohepatic circulation?
- What fraction is excreted unchanged in the kidney?
- Does it have a narrow or wide therapeutic index
- 75% F
- 20-40% Protein Bound
- T1/2 = 40 Hours
- Yes, so long T1/2
- 2/3 Excreted Unchanged
- Narrow Therapeutic Index
Major Limitation of Dopamine
Tolerance or Desensitization
The drug choice for patients with congestive heart failure, hypotension and oliguria.
a. Dopamine
b. Dobutamine
c. Isoproterenol
d. Epinephrine
A
Mechanism of Action of Milrinone
Phosphodiesterase 3 Inhibitor causing increased cAMP
Effects of Milrinone
Increased myocardial contractility
Promotes Vasodilation
Mechanism of Action of Nesiritide
Increases cGMP in smooth msucles