Deck 2 Flashcards
(23 cards)
- Q. Where are muscarinic and nicotinic receptors found?
A. Muscarinic acetylcholine receptors are found on all cardiac muscle, smooth muscle and gland cells. –parasympathetic (they can be excitatory or inhibitory)
B. Gq coupled – M1, M3, M5 (Ca2+), Gi/o = M2, M4 (K+)
C. Nicotinic receptors are found on all autonomic nervous system post ganglionic neurons, in the adrenal medulla and at all neuromuscular junctions of skeletal muscle (excitatory when Ach binds). Some CNS pathways.
- Q. Where are acetylecholine, epinephrine and norepinephrine used?
A. Parasympathetic – neurotransmitter is Ach
B. Sympathetic - epinephrine and norepinephrine at the effector (Ach can be found at interneurons)
C. Somatic (conscious) neurotransmitter is Ach
- Q. What are cholinergic agonists?
A. Cholinergic agents produce or alter the release of Ach
B. They can mimic Ach = producing parasympathetic effects
C. Prevent release of Ach – botox (by degrading vesicle proteins)
D. Bind to acetylcholinesterase so Ach cannot be broken down into acetate and choline = build-up of Ach in synaptic cleft
E. Indirect – sarin gas forms strong bonds with acetylcholinesterase
- Q. What side effects occur due to overstimulation of cholinergic agents?
A. DUMBELS (diarrhoea, urination, miosis/muscle weakness/bronchorrhea, bradycardia, emesis, lacrimation, salivation/sweating)
- Q. Name the major difference between noradrenaline and adrenaline?
A. Noradrenaline is considered a neurotransmitter while adrenaline is considered a hormone
- Q. What does each class of adrenoceptor do? Alpha 1/2 and beta 1,2,3
A. Alpha-1; vasoconstriction (vasodilation) also bladder contraction
B. Alpha-2; self-inhibition (reuptake on presynaptic cleft), also acts on the pancreas decreasing insulin
A. Beta-1; most clinically important -heart. Increased force, rate and contraction of heart. Also affects the kidney increasing renin and therefore blood pressure.
B. Beta-2; vasodilation/(vasoconstriction), bronchodilation, also GI decreased motility
C. Beta-3 increased lipolysis, also bladder relaxation
- Q. Is adrenaline a direct-acting (selective) agonist or an indirect-acting (non-selective) agonist? Which adrenoceptors does it target and what are the effects?
A. Adrenaline is a non-selective agonist It targets: B. alpha-1 = vasoconstriction C. beta-1 = positive inotropic effects (increased strength of cardiac contraction) D. beta-2 = bronchodilation
- Q. Define pain? What is the difference between nociceptive and neuropathic pain?
A. An unpleasant, sensory and emotional experience associated with actual or potential tissue damage.
B. Nociceptive: inflammatory
C. Neuropathic: nerve related pain
- Q. Name two differences between A-delta fibres and C fibres
A. A delta fibres – fast, myelinated - carry cold, pressure and some pain signals
B. C afferent fibres – slow, unmyelinated (sudden, sharp prick)
C. A class – thickly myelinated, fast (burning or aching)
- Q. Explain the Rawlin-Thompson/ABCDE system of adverse effects
A. Augmented; commonest, predictable, dose related, self-limiting (manage by lowering dose)
B. Bizarre; unrelated and not expected from known pharmacological action, unpredictable – hypersensitivity etc (manage by withdrawing drug immediately)
C. Chronic; occurs after long therapy, may not be immediately obvious with new medicines
D. Delayed; also occurs after a long period of time after treatment, eg neoplasia
E. End of use; relatively long term (days/weeks), withdrawal reactions
- Q. What are the four main types of hypersensitivity?
A. Type 1 – acute anaphylaxis
B. Type 2 – igG-mediated cytotoxicity
C. Type 3 – Immune-complex deposition
D. Type 4 – T-cell mediated
- Q. Name two features of anaphylaxis?
A. Exposure to drug, immediate onset, rash blotches, swelling of lips and face, hypotension (anaphylactic shock), cardiac arrest
B. Release of histamine, thromboxanes, prostaglandins, TMF and other acute inflammatory mediators
- Q. Name three ways to manage an adverse drug reaction?
A. Continue the drug and manage the ADR by other means, reduce the dose, stop the drug
- Q. Describe a situation in which adverse drug reactions should be reported
A. All suspected ADRs for new medications, all ADRs in children, all serious reactions (fatal, life threatening, disabling, incapacitating, or which result in or prolong hospitalisation).
- Q, Name two risk factors that may increase drug interactions a) Patient related b) Drug related
A. Patient related; polypharmacy, old age, genetics, hepatic disease, renal disease
B. Drug related; narrow therapeutic index, steep dose/response curve, saturable metabolism
- Q. What is the concept of homeopathy?
A. “like to treat like”, (modern day medicine is based on allopathy – the treatment of opposites)
- Q. Name two naturally occurring opioids
A. Morphine and codeine (from the opium poppy)
- Q. What is the difference between; a) tolerance b) dependence
A. Tolerance is the down regulation of receptors with prolonged use; this means that higher doses are needed in order to achieve the same effect
B. Dependence is the physical and psychological craving for euphoria
- Q. What is action mechanism of opioids?
A. Opioid receptors are coupled with inhibitory G-proteins and their activation has a number of actions;
B. Closing of voltage sensitive calcium channels
C. Stimulation of potassium efflux leading to hyperpolarisation and reduced cyclic adenosine monophosphate (cAMP) production
D. Overall reduction in neuronal cell excitability – reduced transmission of nociceptive impulses
E. = Inhibition of pain transmitter release at spinal cord and midbrain and modulation of pain perception in higher centres – changes the emotional perception of pain
F. Sustained activation leads to tolerance and addiction
- Q. What side effects are associated with opioids?
A. Respiratory depression; sedation, nausea, vomiting, constipation, itching, immune suppression (dependence and addiction)
- Who is at a higher risk of respiratory depression due to morphine?
A. Morphine (converted to morphine 6 glucuronide in the body) is renally excreted this means that patients with renal failure have a higher risk of respiratory depression
- Codeine is a prodrug; what does this mean?
A. This means that it must be metabolised by cytochrome CYP2D6 within the body to produce any effect
- What is bioavailability? What is the oral bioavailability of morphine?
A. Bioavailability is the proportion of a drug or other substance which enters the circulation when introduced into the body to have an active effect
B. Oral morphine is subject to first pass metabolism by the liver
C. This means that 50% of oral morphine is metabolised before the drug reaches the systemic circulation (so only half the dose must be given parenterally- s/c, IM, IV etc)
D. First-pass metabolism is when the concentration of a drug is reduced before it reaches the systemic circulation.
