Topic 5: Drugs that Affect the neurological system Flashcards
(152 cards)
Barbiturates (No Antidotes)
a class of drugs used to induce sedation; chemical derivatives of barbituric acid
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium)
considered prototypical barbiturate; classified as a long-acting drug
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium) Mechanism of action
CNS depressants acts primarily on brainstem (‘reticular formation’)
- sedative and hypnotic effects are dose related
- act by reducing nerve impulses traveling to area of the brain (cerebral cortex)
- ability to inhibit nerve impulse transmission due in part to ability to potentiate the action of inhibitory neurotransmitter GABA, found in high concentration in CNS
- Barbiturates raise seizure threshold; can be used to treat seizures
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium) Indications
- prevention of generalized tonic-clonic seizures and fever-induced convulsion
- useful in Tx of hyperbilirubinemia in neonates
- rarely used today as a sedative and is no longer recommended to be used as a hypnotic drug
Indications for Barbiturates
All barbiturates have same sedative hypnotic effects but differ in their potency, time to onset of action, and duration of action. The various categories of barbiturates can be used to the following therapeutic purposes: ultrashort, short, intermediate, and long acting
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium) Contraindication
known drug allergy, pregnancy, significant respiratory difficulties, and severe kidney or liver disease. These drugs (barbs) must be used with caution in older adults due to their sedative properties and increased fall risk
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium) Adverse effects
low therapeutic index; long acting, adverse effects relate to the CNS and include drowsiness, lethargy, dizziness, hangover, and paradoxical restlessness or excitement. -Barbs deprive people of their REM sleep which can result in agitation. With most sedative drugs the risk of fall occurs so for older adults it can be suggested to take half of dose
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium) Assessment
- insomnia, any concerns voiced about sleep patterns or disorders, the time it takes to fall asleep, vitals, physical assessment, renal and liver, mental status, miscellaneous info about medical history, use of drugs etc.,
- evaluate cautions, contraindications, and drug interactions
- NOT to be used pregnant or lactating women- these drugs cross the placenta and breast-blood barriers posing a risk for respiratory depression in the fetus and neonate. If women take while pregnant baby will have withdrawal symptoms
Barbiturates (No Antidotes) Phenobarbital (Luminol Sodium) Patient teaching
advice about hangover effects to older patients, encourage to keep journal of sleep, avoid caffeine when trying to go to bed (avoid at least 6 hours before bedtime), keep drugs out of the reach of children, emphasize to take as required, educate about driving or operation of heavy machine while taking those drugs
Difference between sedatives and hypnotics
-Sedatives reduce nervousness, excitability, and irritability
without causing sleep, but a sedative can become a hypnotic if it is given in large enough doses.
-Hypnotics cause sleep and have a much more potent effect on the CNS than do sedatives
Phenobarbital is also used to treat?
status epilepticus (prolonged uncontrolled seizures). In extreme cases, patients may be intentionally overdosed to the extent of causing therapeutic phenobarbital or pentobarbital coma
Benzodiazpenes
a chemical category of drugs most frequently prescribed as anxiolytic (drugs used to reduce intensity of anxiety) drugs and less frequently as sedative-hypnotic agents
Benzodiazpenes Diazepam (Valium) - long acting Mechanism of action
Diazepam (Valium) - long acting
Mechanism of action: sedative and hypnotic action is related to ability to depress activity in CNS. Specifically the hypothalamic, thalamic, and limbic systems of the brain. Because research suggest they are GABA receptors or other adjacent receptors. GABA- primary inhibitory neurotransmitter of the brain and it serves to modulate CNS activity by inhibiting overstimulation
Benzodiazpenes Diazepam (Valium) Indications
treatment of anxiety, procedural sedation, and anesthesia adjunct, anticonvulsant therapy, and skeletal relaxation following orthopedic injury or surgery
Benzodiazpenes Diazepam (Valium) contraindication
drug allergy, narrow-angle glaucoma, and pregnancy
Benzodiazpenes Diazepam (Valium) Adverse effects
can be harmful if dose is mixed with alcohol, headache, drowsiness, paradoxical excitement or nervousness, dizziness, vertigo, cognitive impairment and lethargy. Fall hazard for older population, have comparatively less intense effects on the normal sleep cycle, ‘hangover’ effect is sometimes reported (daytime sleepiness), withdrawal symptoms like rebound insomnia. Amnesia, anorexia, sedation, lethargy, fatigue, confusion, drowsiness, dizziness, ataxia, headache, visual changes, hypotension, weight gain or loss, nausea, weakness
Benzodiazpenes Diazepam (Valium) Toxicity/management
when taken with alcohol, barbiturates, overdose causes somnolence, confusion, diminished reflexes, and coma. Treatment is the antidote Flumazenil
Benzodiazpenes Diazepam (Valium) Interactions
alcohol, opioids, muscle relaxants will cause intense CNS depressant, kava and valerian are herbal supplements that interact and can lead to CNS depression, grapefruit results in prolonged effect, increased effect and toxicity
Benzodiazpenes Diazepam (Valium) Assessment
vitals, identification of disorders or conditions that pose threat for caution or contraindications, monitor suicide, anemic, have history of substance/alcohol abuse, caution pregnant or lactating patients, renal functions or hepatic function studies to help prevent toxicity or complications, pay attention to drug interactions
Benzodiazpenes Diazepam (Valium) Patient teaching
advice about hangover effects to older patients, encourage to keep journal of sleep, avoid caffeine when trying to go to bed (avoid at least 6 hours before bedtime), keep drugs out of the reach of children, emphasize to take as required, educate about driving or operation of heavy machine while taking those drugs
Benzodiazpenes Midazolam (Versed) – short acting Mechanism of action
sedative and hypnotic action related to ability to depress activity in the CNS. Specifically the hypothalamic, thalamic, and limbic systems of the brain. Because research suggest they are GABA receptors or other adjacent receptors. GABA- primary inhibitory neurotransmitter of the brain and it serves to modulate CNS activity by inhibiting overstimulation
Benzodiazpenes Midazolam (Versed) Indication
commonly used preoperatively and for moderate sedation. It has the ability to cause amnesia and anxiolysis (reduced anxiety), as well as sedation
Benzodiazpenes Midazolam (Versed) contraindications
drug allergy, narrow-angle glaucoma, and pregnancy
Benzodiazpenes Midazolam (Versed) adverse effects
harmful if dose mixed with alcohol, headache, drowsiness, paradoxical excitement or nervousness, dizziness, vertigo, cognitive impairment and lethargy. Fall hazard for older population, have comparatively less intense effects on the normal sleep cycle, ‘hangover’ effect is sometimes reported (daytime sleepiness), withdrawal symptoms like rebound insomnia. Amnesia, anorexia, sedation, lethargy, fatigue, confusion, drowsiness, dizziness, ataxia, headache, visual changes, hypotension, weight gain or loss, nausea, weakness