B - 8. B-receptor antagonists Flashcards
B1 receptors
Heart - HR up, contractility up
Kidney - renin release increased -> BP increase (increased Na+ retention)
B2 receptors
- vessels supplying muscles and brain - vasodialation
- lungs - bronchodialation
- GI - decreased motility and absorption
- Eyes - increased aqeous humor production
- Liver - increased glucose release
- Pancreas - increased glucagon release
- increased free fatty acids and cholesterol in blood
1st gen beta blocker names
Non-selective
Propranolol (only one that breaches BBB)
Pindolol (partial agonist - same but weaker effect)
Timolol
Sotalol
1st gen beta blocker effects
- HR and contractility of heart decreased
- —> decreases cardiac oxygen demand and BP
- Inhibits renin release - sodium excretion increased -> BP lowered
- mild vasoconstriction
- decreased airflow in lungs due to bronchoconstriction
- GI motility increase
- decreased intraocular pressure
- decreased serum glucose (pancreas has lowered glucagon release)
1st gen beta blocker indications
- Hypertension, CAD, CHF (controversial)
- Severe tachycardia (thyroid storm)
- Anxiety
Propranolol - migraine (BBB breach)
Timolol - glaucoma (decreased intraocular pressure)
Side effects (mainly 1st gen)
- Bradycardia, hypotension
- —> rebound hypertension if quit suddenly
- fatigue (less blood flow to muscles)
- dizziness, depression, insomnia, nightmares (especially - propranolol)
- Wheezing, dyspnea
- Diarrhea, hypoglycemia
2nd gen beta blocker target and names
Selective for B1
Metoprolol
Bisoprolol
(these two are good for CHF)
Esmolol
Nebivolol
can block B-2 in high doses
3rd gen beta blocker target and names
Both a1 and non-selective B-blocking
Carvedilol
3rd gen indications
Good against hypertension where vasoconstriction is problematic
Antioxidant properties
