L12 Predicting Adverse Drug Effects Flashcards
Parasympathetic activation on
- Iris
- Lacrimal and salivary glands
- Heart contraction
- Lungs
Contract ciliary muscles, iris
Secretion: Lacrimal glands and salivary glands
Decrease rate and force of heart contraction
Bronchoconstriction of lungs
Sympathetic activation on
- Iris
- Lacrimal and salivary glands
- Heart contraction
- Lungs
Contraction: Iris and radial muscles
Secretion: Salivary glands, BVs, Head and Neck
Increase rate and force of heart contractiom
Lungs: Bronchodilation
Acetylcholine action in the sympathetic and parasympathetic system
Neurotransmitter for parasympathetic system (Nicotinic to muscarinic)
sympathetic (nicotinic to adrenoreceptor)
Treatment of hypertension - increase parasympathetic nervous system [4]
Give a muscarinic agonist - atropine
Prevent breakdown of Ach (use anticholinesterase - neostigmine)
Side effects: Visual disturbances, lacrimation, salivation and bronchoconstriction
Stomach cramps, diarrhoea and incontinence
Treatment of hypertension - decrease sympathetic nervous system
Give adrenoreceptor antagonist and prevent noradrenaline release
Beta-1 adrenoreceptors cause inotropism (contraction) and chronotropism (rhythm)
Alpha-adrenoreceptor cause vasoconstriction
Beta-2 adrenoreceptors cause vasodilation
Mixed alpha/beta antagonist (carvedilol and labetalol) = decreased CO, decreased blood flow (skeletal muscle) and increased blood flow to skin and gut
Adverse effect: Bronchoconstriction, postural hypotension, bradycardia, muscle weakness/fatigue and cold extremities
Treatment of Hypertension - selective alpha antagonist
Selective alpha antagonist - phentolamine
Increased blood flow to skin and gut (decreased peripheral resistance)
Adverse effects: postural hypotension, headache and reflex tachycardia
Treatment of Hypertension - Non-selective beta antagonist
Nonselective beta antagonist - propanolol
Decreased blood flow (skeletal muscle) and decreased cardiac output
Adverse effect: Bronchoconstriction and muscle weakness/fatigue
Treatment of Hypertension - selective beta-1 antagonist
Selective beta-1 antagonist - atenolol
Decreased cardiac output and no effect on blood flow = decreased BP
Treatment of Hypertension - Combined beta-1 antagonist and beta-2 agonist
Combined beta-1 antagonist and beta-2 agonist
Decreased CO, Bronchodilation and increased blood flow (skeletal muscle)
Common cold treatment
• Decrease blood flow to nose = decrease production of nasal secretions
• Nasal decongestants are alpha-adrenoreceptor agonists (phenylephrine)
• Adverse effects: decreased blood flow to skin and gut = increased peripheral resistance = increased BP
Limit adverse effects: Local administration (nasal spray)
Asthma treatment - decrease parasympathetic activity
Decrease activity of parasympathetic NS
Muscarinic antagonist
Adverse effects: Blurred vision, dry mouth and tachycardia (constipation + urinary retention)
Asthma treatment - Increase activity sympathetic NS
• Beta-2 agonist = bronchodilation
• Adverse effects: Increase blood flow (skeletal muscle - decreased peripheral resistance) and tachycardia (dose dependent)
• Limit adverse effect by local administration: aerosol inhaler - salbutamol
Muscarinic antagonist ipratropium bromide used as aerosol to provide local effects
