ANS Flashcards
(25 cards)
What does the autonomic nervous system regulate?
Involuntary functions necessary to life, such as:
* Cardiovascular system
* Smooth muscle fibers
* Exocrine glands
The autonomic nervous system shares several properties with the endocrine system.
Define sympathomimetics
Drugs that produce actions similar to sympathetic nerve stimulation.
These drugs mimic the physiological effects of the sympathetic nervous system.
List local uses of sympathomimetics
- Local anesthesia
- Hemostatic nasal pack in epistaxis
- Eye drops (e.g., Dipivefrin)
- Inhalation in bronchial asthma
What are the systemic uses of sympathomimetics?
- Cardiac resuscitation (intracardiac)
- Bronchial asthma (SC)
- Anti-allergic in anaphylactic shock
- Hypoglycemia
What are common side effects of sympathomimetics?
- Hypertension
- Cerebral hemorrhage
- Gangrene if used with local anesthesia in end arteries
- Ventricular arrhythmia
- Anxiety, tremors, insomnia
What is the use of Ephedrine?
- Spinal anesthesia
- Attention Deficit Hyperactive Disorder in children
- Heart block
- Analeptic in toxicity with CNS depressant
- Anti-allergic
- Bronchial asthma prophylaxis
- Mydriatic eye drops
- Nasal decongestant
- Nocturnal enuresis
List side effects of Ephedrine
- Anxiety
- Insomnia
- Tremors
- Urine retention in males with enlarged prostate
- Tachyphylaxis
What are the uses of Amphetamine?
- Attention Deficit Disorder
- Anorexigenic (obesity)
- Depression in parkinsonism
- Fatigue and hypersomnia
- Narcolepsy
List side effects and toxicity of Amphetamine
- Convulsion
- Anxiety
- Anorexia
- Addiction
- Hallucination
- Coma
- Hypertension
- Palpitation
- Arrhythmia
What are alpha-agonists (vasopressors)?
Drugs that stimulate α receptors, causing vasoconstriction and increased peripheral resistance, leading to increased blood pressure.
They are mainly used in the treatment of hypotension.
Name some alpha-agonists.
- Noradrenaline
- Ephedrine
- Phenylephrine
- Midodrine
What do alpha blockers do?
Block and reverse the hypertensive effect of adrenaline and noradrenaline.
What is the use of Tamsulosin?
Treatment of benign prostatic hyperplasia with minimal effect on blood vessels.
List uses of non-selective alpha blockers like Phentolamine.
- Peripheral vascular disease (e.g., Raynaud’s disease)
- Diagnosis of pheochromocytoma
- Sustained type hypertension due to excess catecholamines
What are the uses of Phenoxybenzamine?
- Hypertension in pheochromocytoma
- Peripheral vascular disease
- Shock
List side effects of Phenoxybenzamine.
- Dry mouth
- Tachycardia
- Sedation
- Flush and congestion
- Postural hypotension
What are the uses of Prazosin (Minipress)?
- Resistant heart failure
- Hypertension
- Benign prostatic hypertrophy (BPH)
List side effects of Prazosin.
- Postural hypotension
- Initial syncopal attack (1st dose phenomenon)
- Salt and water retention
- Failure of ejaculation
- Angina pectoris may be precipitated
- Allergy
- Headache
What are the classifications of B-blockers?
- Propranolol (Inderal) - Non-selective B-blocker
- Lipophilic
- Extensive hepatic first pass metabolism
- Bound to plasma proteins
What are the cardiovascular effects of B-blockers?
- Negative inotropic, chronotropic, and dromotropic effects
- Decrease cardiac work
- Useful in angina
- Antiarrhythmic due to decreased excitability
- Decrease blood pressure after 4 weeks
List the metabolic effects of B-blockers.
- Hypoglycemia
- Decrease free fatty acids
- Hyperkalemic effect
What are the side effects and contraindications of B-blockers?
- Heart failure
- Heart block
- Raynaud’s phenomenon
- Cold extremities
- Hypotension
- Sedation
- Depression (only lipophilic drugs)
- Precipitate bronchospasm
- Sudden withdrawal leading to sympathetic overactivity
- Impotence (rare complication)
What is Labetalol?
A drug that blocks both α and β receptors, leading to decreased blood pressure without reflex tachycardia and has anti-renin action.
Used in hypertensive emergencies, hypertension in pregnancy, and pheochromocytoma.
Define pheochromocytoma.
Tumor of the adrenal medulla secreting noradrenaline (90%) and adrenaline (10%).
