DRUGS ACTING ON THE AUTONOMIC NERVOUS SYSTEM Flashcards
What is peripheral nervous system includes?
Includes the somatic and autonomic nervous systems which control voluntary and involuntary functions respectively.
Which part of spine Sympathetic nervous system arise from ?
Arises from the thoracic and lumbar areas of the spinal cord.
The preganglionic fibers for the parasympathetic nervous system arise from the cranial and sacral nerves.
Autonomic nervous system pharmacology refers to?
Study of drugs that affect the functioning of the autonomic nervous system, which controls many of the involuntary bodily functions, including heart rate, blood pressure, digestion, and respiratory rate. These drugs can either mimic or block the actions of neurotransmitters, such as acetylcholine and norepinephrine, that are released by the autonomic nervous system.
Autonomic drugs can be classified as
Sympathetic or Parasympathetic drugs
The autonomic nervous system is further divided into
Sympathetic nervous system and Parasympathetic nervous system.
Sympathetic nervous system is responsible for
“fight or flight” response in the body. When activated, it increases heart rate, blood pressure, and respiratory rate.
The parasympathetic nervous system is responsible for the “rest and digest” response in the body. When activated, it slows down heart rate, decreases blood pressure,
“rest and digest” response in the body. When activated, it slows down heart rate, decreases blood pressure.
What is the Third division of autonomic nervous system?
Enteric nervous system, which regulates the digestive tract’s motility and secretion.
Autonomic nervous system is essential for
regulating many of the body’s vital functions and maintaining homeostasis.
Which are two important neurotransmitters in the autonomic nervous system?
Acetylcholine and Nor-adrenaline (norepinephrine)
What is Acetylcholine?
Acetylcholine is a neurotransmitter which is released after stimulation of the parasympathetic nervous system to act on effector organs (cells) to elicit their response
What is the function of neurotransmitter?
Provide passage of an impulse across a synapse
what is cholinergic receptor?
A type of receptor that binds to the neurotransmitter acetylcholine. These receptors are found throughout the body, including in the brain, the neuromuscular junction, and other organs.
What are two types of cholinergic receptors?
Nicotinic and Muscarinic.
Nicotinic receptors mediate
muscle contraction
Muscarinic receptors are found in
brain and in smooth muscle
What is the function of Muscarinic receptors?
Regulation of heart rate, smooth muscle contraction, and glandular secretion.
Cholinergic drugs are also called
Parasympathomimetics
How many groups of cholinergic drugs?
2 groups. Direct-acting and Indirect-acting
There are two sub group of direct-acting cholinergic drugs:
Esters of choline and Cholinergic alkaloids
What are Esters of choline drugs?
Methacholine, Carbachol, Betanechol
What are Cholinergic alkaloids drugs?
Pilocarpine, Muscarine, Arecoline, Nicotine
BETANECHOL is contraindicated to?
Bronchial asthma, Hyperthyroidism, Peptic ulcer disease, Coronary insufficiency
What is PILOCARPINE Indication?
Glaucoma
What is PHYSOSTIGMINE Indication?
- Glaucoma
- Atropine over dosage
What is NEOSTIGMINE Indication?
- Myasthenia gravis
- Paralytic Ileus
- Reversal of effect of muscle relaxants, e.g. tubocurarine
- Post operative urine retention
What is effect of ATROPINE in eye?
- Relaxation of constrictor pupillae (mydriasis)
- Relaxation or weakening of ciliary muscle (cycloplegia-loss of the ability
to accommodate)
What is effect of ATROPINE in CNS?
- Lower doses produce sedation
- Higher doses produce excitation, agitation and hallucination
What is effect of ATROPINE in CVS?
- Blocks vagal parasympathetic stimulation (tachycardia)
- Vasoconstriction
What is effect of ATROPINE in Respiratory?
Bronchodilatation and reduction of secretion
What is effect of ATROPINE in GIT?
Relaxes smooth muscle of ureter and bladder wall; voiding is slowed
What is effect of ATROPINE in Sweat Glands?
Suppresses sweating
What are clinical indication for Atropine?
Pre anesthetic medication -to reduce the amount of secretion and to prevent excessive vagal tone due to anesthesia.
As antispasmodic in cases of intestinal, biliary, and renal colic
Heart block
Hyperhidrosis
Organophosphate poisonings
What are side effects of Atropine?
- Dryness of the mouth, tachycardia and blurred vision
- Retention of urine
What are contraindication of Atropine?
Glaucoma and Bladder outlet obstruction.
What is Pharmacokinetics of Atropine
Atropine is absorbed completely from all sites of administration except from the skin wall, where absorption is for limited extent; it has good distribution. About 60% of the drug is excreted
unchanged in urine.
HYOSCINE is also called
SCOPOLAMINE