- •Simplicified version! Drugs Affecting the Afferent Innervation
- •Indications:
- •Indications 3 - 6
- •Indication 1
- •Indication 2
- •Indications:
- •(CholinOnegative drugs)
- •Anticholinesterases
- •Muscarinic agonists (m-cholinomimetics)
- •Nicotinic agonists (n-cholinomimetics)
- •Simplicified version
- •(Cholinonegative drugs)
- •Muscarinic antagonists (m-cholinoblockers)
- •Nicotinic antagonists (n-cholinoblockers)
- •Ganglion-blocking drugs
- •Neuromuscular blocking drugs (myorelaxants)
- •Simplicified version
- •(Adrenopositive drugs)
- •Indirect adrenomimetics
- •Direct adrenomimetics
- •Mixed action Adrenomimetics
- •Alfa-adrenomimetics
- •Beta-adrenomimetics
- •Simplicified version
- •(Adrenonegative drugs)
- •Sympatholytics
- •Alfa-adrenoblockers
- •Beta-adrenoblockers
- •General anesthetics
- •Analgesic drugs
- •Hypnotic drugs
- •Antiepileptic drugs (anticonvulsants)
- •Sedative drugs
- •Anxyolytics (antianxiety drugs, tranquillizers)
- •Antipsychotic drugs (neuroleptics)
- •Analeptics
Muscarinic agonists (m-cholinomimetics)
List of drugs
Pilocarpine hydrochloride
Mechanism of action
Direct stimulation of M-cholinoreceptors. Don’t stimulate N-cholinoreceptors!
Pharmacological effects
Type of receptors |
Organ |
Effect |
Stimulation of M-cholinoreceptors |
Eye |
Constriction of pupil (miosis) |
Salivary glands |
Increasing of saliva secretion |
|
Heart |
Decreasing of heart rate, heart contractility, heart conductance and heart excitability |
|
Bronchi |
Constriction (due to contraction of smooth muscles of bronchi) |
|
Gastro-intestinal tract (GIT) organs: stomach, small intestine, gall bladder etc. |
Increasing of motility (due to contraction of smooth muscles of GIT organs) |
|
Urinary bladder |
Constriction (due to contraction of smooth muscles of urinary bladder) |
Indications
1. Glaucoma (increasing of intraocular pressure)
Pilocarpine → constriction of pupil → decreasing of intraocular pressure → treating of glaucoma.
This effect depends on M-cholinoreceptors.
Nicotinic agonists (n-cholinomimetics)
List of drugs
Lobeline hydrochloride
Mechanism of action
Direct stimulation of N-cholinoreceptors. Don’t stimulate M-cholinoreceptors!
Pharmacological effects
The most important effect is the stimulation of N-cholinoreceptors of carotid sinus (angle of bifurcation of the common carotid artery). As consequence, there will be the reflex stimulation of respiratory center → increasing of respiratory rate and respiratory depth.
Indications
1. Reflex inhibition of breathing (e.g., asphyxia caused by drowning).
Lobeline → stimulation of N-cholinoreceptors of carotid sinus → stimulation of respiratory center → restoration of breathing.
Simplicified version
(Cholinonegative drugs)
Muscarinic antagonists (m-cholinoblockers)
List of drugs
Nonselective M-cholinoblockers: Atropine sulfate, Belladonna extract (contains atropine!),
Metocinii iodidum, Scopolamine
Selective M-cholinoblockers: Pirenzepine, Ipratropium bromide, Platyphyllini hydrotartras
Mechanism of action
Competitive blockage of M-cholinoreceptors.
Pharmacological effects
Previous time you studied the pharmacological effects of Muscarinic agonists (M-cholinomimetics (see my previous material). For today topic «Muscarinic antagonists (M-cholinoblockers)» pharmacological effects will be strongly opposite (see table):
Type of receptors |
Organ |
Effect |
Blockage of M-cholinoreceptors |
Eye |
Dilation of pupil (mydriasis) |
Salivary glands |
Decreasing of saliva secretion |
|
Heart |
Increasing of heart rate, heart contractility, heart conductance and heart excitability |
|
Bronchi |
Dilation (due to relaxation of smooth muscles of bronchi) |
|
Gastro-intestinal tract (GIT) organs: stomach, small intestine, gall bladder etc. |
Decreasing of motility (due to relaxation of smooth muscles of GIT organs) |
|
Urinary bladder |
Relaxation (due to relaxation of smooth muscles of urinary bladder) |
Indications
1. Dilation of pupil to treat iritis (inflammation of iris): atropine
Dilation of pupil for diagnostic purpose (looking for eye diseases): metocinium
2. Preventing of some complications of general anaesthesia during surgery (premedication) – preventing of excessive secretion of salivary glands and bronchi, preventing of bronchospasm, cardiac arrest etc.: atropine, metocinium.
3. In cases of decreasing of heart conductance (e.g. atrioventricular heart block (AV block)):
Atropine.→ increasing of heart conductance → relieving of atrioventricular heart block
4. Relieving and prophylaxy of bronchospasm
Platyphyllinum, Ipratropium → dilation of bronchi → relieving and prophylaxy of bronchospasm.
5. Treatment of gastric hyperacidity, gastric ulcer, duodenal ulcer:
Atropine, Belladonna extract, Pirenzepine → decreasing of secretion of gastric juice → treating of gastric hyperacidity, gastric ulcer and duodenal ulcer.
6. Relieving of renal colic, hepatic colic, intestinal colic.
Atropine, Belladonna extract, Platyphyllinum → relaxation of smooth muscles of kidneys, liver and intestine → relieving of renal colic, hepatic colic, intestinal colic.
7. Motion sickness (during travelling in aeroplane or ship):
Scopolamine → decreasing of nausea and vomiting during travelling in aeroplane or ship.
NB! You should study all drugs, but the most important drugs (first choice drugs) underlined.