Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
PathopharmA 2
neurolo chapter 20,24, 25
| Question | Answer |
|---|---|
| chapter 20 | |
| Central Nervous System (CNS) Drugs | Agents that act on the brain and spinal cord Medical uses Relief of pain Suppression of seizures Production of anesthesia Treatment of psychiatric disorders |
| DRUGS | Nonmedical uses Stimulant, depressant, euphoriant, and other “mind-altering” abilities |
| Transmitters of the CNS | Peripheral nervous system: Acetylcholine, norepinephrine, and epinephrine CNS: At least 21 compounds that serve as neurotransmitters PRESENCE OF neurotransmitter role for dopamine, norepinephrine, serotonin, and enkephalins , BUT LOT STILL UNKNOWN |
| The Blood-Brain Barrier Not fully developed at birth | Impedes entry of drugs into the brain“Mixed Blessing”•Keeps out toxic substances•Can also be a barrier to therapeutic substancesPassage across the blood-brain barrier limited to lipid-soluble drugsProtein-bound or highly ionized drugs cannot cross |
| Adaptation of the CNS to Prolonged Drug Exposure | Different effects possible when drug is taken chronically versus the initial use of the drug (d/t adaptive changes) Increased therapeutic effects over time START WORKING IN 4-8 WEEKS DUE TO CNS ADAPTING TO DRUG |
| SEIZURE-WHEN DID THE AURA STARTED, WHAT TIME, HOW DID THEIR PRESENT DURING THE EPISODE-how often and what type od seizure Adaptation of the CNS to Prolonged Drug Exposure | PROLONGED TREATMENT DECREASE SIDE EFFECTS,BUT THE THERAPEUTIC EFFECT REMAINS THE SAME COUD DEVEOP TOLERANCE PHYSICL DEPENDENCE : WITHDRAWING S/S; JITTERINESS, sweating, goosebumps, vomiting, anxiety, insomnia, and muscle pain. |
| Psychotherapeutic Drugs | Difficult and Slow! Complexity of mental health Lack of adequate animal models of mental illness Mentally healthy individuals cannot be used as subjects • No effect or paradoxical effects • Psychopharmacologic accidental discoveries |
| Difficult and Slow! Complexity of mental health Lack of adequate animal models of mental illness Mentally healthy individuals cannot be used as subjects • No effect or paradoxical effects • Psychopharmacologic accidental discoveries | There are numerous neurotransmitters Their precise functional roles are not clear Their complexity makes it difficult to know with certainty just how CNS drugs produce their effects |
| Chapter 24 | AED-CAUSES -SUICIDAL THOUGHT-DEPRESSION(WORSEN WITH ALCOHOL, ANTIHISTAMINE, OR OPIODS} |
| Definition of Seizure Disorders May also cause problems with learning, memory, and mood | FIRING OF SEIZURE -excessive excitability of neurons in the central nervous system -Seizures are initiated by discharge from a group of hyperexcitable neurons, called a focus(PLACE WHERE IT STARTS) |
| Focus may result from the following: | Congenital defects Hypoxia at birth Head trauma Brain infection Stroke Cancer Genetic disorders |
| Partial (focal) seizures | - excitation undergoes limited spread from the focus to adjacent cortical areas TYPES: Simple partial Complex partial Secondarily generalized |
| DRUGS- PHENYTOIN(OLDER AGENT) Traditional AEDs • Phenytoin, fosphenytoin, carbamazepine, valproic acid, ethosuximate, phenobarbital, and primidone | Selective inhibition of Na channel TE 10 to 20 mcg/mL( Narrow -SLOW liver’s capacity to metabolize phenytoin) ADR Nystagmus, Sedation, Ataxia, Diplopia, Cognitive impairment Gingival hyperplasia, Skin rash, Effects in pregnancy Cv effects |
| OXCARBAMAZEPINE(NEWER AGENT-BETTER TOLERATED total of 14) Stevens-Johnson syndrome Toxic epidermal necrolysis hyponatremia (<125 mmol/L) | MONOTHERAPY AND ADJUNCTIVE THERAPY IN CHILDREN AND ADULTS BLOCK Electrical Na channel=suppress hyperexcitable neurons stabilized, and seizures ADR Dizziness, drowsiness, double vision, nystagmus, headache, nausea, vomiting, and ataxia- |
| LAMICTAL TE: Broad spectrum of antiseizure activity Bipolar disorder ADR Dizziness, diplopia, blurred vision, nausea, vomiting, and headache Severe skin reactions Aseptic meningitis Risk for suicide | GABAPENTIN TE: Adjunctive therapy of partial seizures Off-label use: Neuropathic pain, prophylaxis of migraine, treatment of fibromyalgia, and relief of postmenopausal hot flashes |
| GENERALIZED SEIZURE | Tonic-clonic-JERK MUSCLE-INCONTINENCE-LOSS OF CONSCIOUNESS Absence (petit mal)-FROM BODY 10-30sec Atonic-LOSS MUSCLeTONE Myoclonic-MUSCLE RIGIDITY Status epilepticus-CONTINIOUS, IF DOESNT STOP=911 Febrile-RESPONSE TO FEVER IN YOUNG CHILDREN |
| PHENYTOIN Decreases the effects of oral contraceptives, warfarin, and glucocorticoids Increases levels of diazepam, isoniazid, cimetidine, alcohol, and valproic acid Dosing: Highly individualized | Gingival hyperplasia: Swelling, tenderness, and bleeding of the gums Gingivectomy Folic acid (0.5 mg/day) may prevent gum overgrowth Risk can be minimized by good oral hygiene, including dental flossing and gum massage |
| VALPROIC not o be used during pregnancy, unless it is the only AED that works | 80-100mcg a broad-spectrum AED FOR partial seizures , tonic-clonic, absence, atonic, and myoclonic ADR FATAL LIVER FAILURE IN <2YRS OLD TAKING OTHER AED fatal pancreatitis. teratogenic- reduce the IQ of children exposed to it in utero |
| CARBAMAZEPINE decrease oral contraceptives | PREFERRED B/C BETTER TOLERATED ADR leukopenia, anemia, and thrombocytopenia—and, very rarely, fatal aplastic anemia. SJS/TEN. Risk is clearly increased by the HLA-B*1502 gene variation DECREASE RISK OF TOXICITY - CBC at baseline and thereafter |
| TARGET OF AED gamma-aminobutyric acid (GABA) | EFFECT Suppress discharge of neurons within a seizure focus Suppress propagation of seizure activity from the focus to other areas of the brain MOA Suppression of Na-Ca influx Antagonism of glutamate Potentiation (GABA) |
| Goals of Treatment | Reduce seizures to a level that allows the patient to live as normal a life as possible Balance the desire for complete seizure control with acceptable side effects -DUE TO SEDATION PATIENT FEAR HAVING ANOTHER SEIZURE-COULD BE TEENS OR ADULT |
| Epilepsy: Therapeutic Considerations | Treatment options Neurosurgery Vagal nerve stimulation Ketogenic diet-makes it difficult for teens to adhere Medication Diagnosis Physical, neurologic, and laboratory evaluations along with a thorough history Electroencephalogram- |
| Epilepsy: Therapeutic Considerations | Drug evaluation Antiepileptic drug (AED) trial period- • Precautions? Dosage adjustment Seizure frequency chart-NEED TO KNOW WHEN, HOW LONG IS IT LASTING-FOLLOW UP S/S |
| Epilepsy: Therapeutic Considerations | Monitoring plasma drug levels Promoting patient adherence Withdrawing antiepileptic drugs SLOW! 6 weeks - months-TO PREVENT SE Suicide risk: Antiepileptic drugs Topirimate and Lamotrigine as AED |
| FACTS | Rarely, phenytoin causes severe skin reactions: StevensJohnson syndrome (SJS) or toxic epidermal necrolysis (TEN) . Risk may be increased by the HLA-B*1502 gene variation, seen almost exclusively in patients of Asian descent. |
| FACTS Fetal risk can be minimized by avoiding valproic acid and by using just one AED (if possible) in the lowest effective dosage. | All traditional AEDs (and some newer AEDs) can harm the developing fetus(1st trim.) However, women with major seizure disorders should continue taking AEDs throughout pregnancy TO MINIMIZE RISK |
| IMPORTANT | Initial control of generalized convulsive SE is accomplished with an IV benzodiazepine—either diazepam or lorazepam. When diazepam is used, follow-up treatment with phenytoin or fosphenytoin is essential for prolonged seizure suppression. |
| CHAPTER 25 | |
| Drugs for Muscle Spasm and Spasticity | - skeletal muscle relaxation One group for localized muscle spasm One group for spasticity Most drugs (except dantrolene) produce their effects through actions in the central nervous system (CNS) Groups are not interchangeable |
| Muscle spasm-RELAXE-TIGHTEN UP-RELAX | Involuntary contraction of muscle or muscle group Causes Epilepsy Hypocalcemia Pain syndromes: Acute and chronic Trauma: Localized skeletal muscle injury-I.E CAR ACCIDENT |
| Treatment of spasm | Pharmacologic therapy Analgesics Acetaminophen NSAIDs • Centrally acting muscle relaxants Cyclobenzaprine Physical measures • Warm compresses • Whirlpool baths • Physical therapy |
| Centrally Acting Muscle Relaxants Cyclobenzaprine | first line drug Not for spacticity ADR Generalized CNS depression Anticholinergic effects Cardiac rhythm disturbances Interactions • Serotonin syndrome with some antidepressants • Alcohol and other CNS depressants |
| Spasticity-CONTINUOUS CONTRACTION-INCREASED MUSCLE TONE | Movement disorders of CNS origin common causes: Multiple sclerosis, cerebral palsy, and spinal cord injury Characteristics include the following: • Heightened muscle tone • Spasm • Loss of dexterity |
| Baclofen [Lioresal] NOT used with stroke ■ relieves spasticity by mimicking the inhibitory actions of GABA in the CNS | TE Multiple sclerosis, spinal cord injury, and cerebral palsy Decreases flexor and extensor spasms Suppresses resistance to passive movement No direct effect on skeletal muscle so doesn’t cause muscle weakness-ACT ON CNS |
| Baclofen [Lioresal] | ADR No antidote for overdose withdrawal over 1 to 2 weeks • Abrupt intrathecal withdrawal: Risk for rhabdomyolysis-break down of muscle=clog kidneys CNS depressant Gastrointestinal symptoms (eg, nausea, constipation) Urinary retention |
| Dantrolene | MOA Acts directly on skeletal muscle Suppresses the release of calcium from the sarcoplasmic reticulum TE Spasticity associated with multiple sclerosis, cerebral palsy, and spinal cord injury Malignant hyperthermia - succinylcholine |
| Dantrolene | Adverse effects Hepatic toxicity Muscle weakness Drowsiness Diarrhea Acne-like rash |
| FACTS | ■ Spasticity is treated with four drugs: baclofen, diazepam, dantrolene, and tizanidine |
| FACTS AVOID ALL CNS DEPRESSANTS | Abrupt discontinuation of intrathecal baclofen can lead to rhabdomyolysis, multiple organ system failure, and death. |
Created by:
Seka_nurse
Popular Science sets