7926480
Description
Flashcards by Margaret-Estefani Conde Paredes, updated more than 1 year ago
|
Created by Margaret-Estefani Conde Paredes
over 7 years ago
|
|
| Question | Answer |
| Which are the tactics on which drug action on the CNS is based? | 1) to increase transmitter function by either: a) increasing the availability of a transmitter (Parkinsons disease and depression where more precursor is supplied or metabolism or uptake is blocked) b) by receptor activation (e.g in anxiety and epilepsy with the ben by receptor activation (e.g in anxiety and epilepsy with the benzodiazepines or as in opiate analgesia) 2) to decrease transmitter function via antagonists (e.g. anti-schizophrenic drugs) |
| Why is it harder to quantify symptoms of CNS disorders? | - multiple receptors - receptors up and down regulate in response to drugs -the CNS is complex, so too are the synaptic connections and transmitters can have actions at many sites in the brain. As a result there can be problematic side-effect although if different effects of transmitter are mediated by different receptors then drugs selective for receptors can be useful for therapy. Also a drug effect can initiate feedback responses (excitatory or inhibitory) and prolonged stimulation or blockade or receptors can lead to receptor down or up regulation. - Drugs acting on the CNS have to cross the blood brain barrier and this presents particular problems for drugs based on peptides that penetrate poorly into the CNS. Non-peptide drugs acting at the receptors for peptide transmitters indicate that these recently characterised systems may be very important for therapeutic targets. |
| What is Epilepsy and how does it work? | * a motor disorder where uncontrolled neuronal activity drives motor systems and hence the fits and convulsions. * overactive glutamate transmission or reduced GABA function (the balance thus shifts to excess firing of neurones) |
| What are the treatments for epilepsy? | - drugs that block Na channels and so reduce repetitive firing of cells - drugs that enhance GABA activity, barbiturates open Cl channels and so cause major inhibitions-they are used for severe cases whereas the benzodiazepine enhance GABA transmission and so are gentler in their effects |
| What is anxiety and how does it work? | - a mood disorder that can be triggered by external events and ranges from mild to debilitating - excess activity is thought to be due to 5HT possibly via reduced GABA inhibition of this monoamine |
| What is the treatment for anxiety? | - benzodiazepine or drugs that act on 5HT1 receptors |
| What is schizophrenia and how does it work? | - a disorder of mood and though precesses that involves increased dopamine function (but in pathways that are not those that fail in Parkinson's disease) -patients have hallucinations, become withdrawn and the altered thought patterns can result in paranoia and suspicions |
| what is the treatment for Schizophrenia? | -drugs that block the DA2 receptor. (too much drug and patients have motor problems) |
| What is Parkinson's disease and how does it work? | - symptoms result from a single transmitter deficit due to the loss of dopamine in neurones in the substantia nigra -degeneration of these neurones means that dopamine is depleted from the nigrostriatal projection zones in the striatum - the cause of the neuronal death is unknown but it is likely that about 70-80% of the nigrostriatal neurones have to die before the symptoms appear - there are muscle rigidity, akinesia (poverty of movement) and tremor at rest |
| What is the treatment for Parkinson's disease? | -> L-DOPA, the precusor for dopamine, given together with drugs that reduce metabolism of both L-DOPA and dopamine |
| What is Alzheimer's and how does it work? | -disease of mood and cognition where memory and communication become disrupted -thought to be due to neuronal degeneration, partly acetylcholine pathways. The major roles of this transmitter in the autonomic and motor systems makes the approaches used in Parkinson's almost impossible to apply and so dementias are only weakly responsive to anticholinesterases |
| What is depression and how does it work? | -can be triggered by external events - is part of the mood changes that life brings - monoamine transmitters, NA and 5HT are critical for mood control and treatments are based on the block of their reuptake or metabolism- this results in increased synaptic levels of these transmitters |
| What is pain? | - a disorder of excess activity that results from peripheral and central events -pharmacology of pain transmission and analgesia exhibits considerable plasticity |
| what are the two major types of pain? | -acute pain: involves activation of sensory receptors on peripheral C-fibres= |
| What are the treatments for pain? | -morphine acts on the mu receptor, and so do most of the clinically used opioid drugs -this mu receptor is the receptor for endogenous opioid peptides ans is remarkably similar in structure and in function all species studied so that basic studies of action of morhphine are at spinal and brain stem/midbrain loci. The spinal actions of opioids and their mechanisms of analgesia involve 1) reduced transmitter release from nociceptive C-fibres so that spinal neurones are less excited by incoming painful messages, and 2) post-synaptic inhibitions of neurones conveying information from the spinal cord to the brain. Further actions within the brain on NA and 5HT pathways result in more pain suppression and a reduction in anxiety but side effects such as respiratory depression, nausea and dependence |
Want to create your own Flashcards for free with GoConqr? Learn more.