Nervous system Flashcards
What is the main aim of treatment for epilepsy and other seizure disorders?
to prevent the occurrence of seizures
by maintaining an effective dose of one or more antiepileptic drugs
What is recommended regarding the dosage frequency of antiepileptic drugs?
should be kept as low as possible so patient adheres
.
but if patient has a large dose, may need to give it more frequently to avoid adverse effects associated with high plasma-drug concentration
Why is monotherapy with first or second line antiepileptic drugs preferred?
to reduce the risk of adverse effects and drug interactions that may occur with using multiple drugs
What cautionary advice has been provided by MHRA/CHM regarding switching between different manufacturers’ products of antiepileptic drugs? (2)
Loss of seizure control
and/or worsening of side effects
What should be done if a patient needs to be maintained on a specific manufacturer’s product of antiepileptic drug? (2)
prescribed by brand name
or by using the generic drug name along with the name of the manufacturer.
How should adverse reactions to antiepileptic drugs be reported?
Yellow Card
What should be done if a prescribed antiepileptic drug product is unavailable?
use one from a different manufacturer
Which antiepileptic drugs fall under the category where patients should be maintained on a specific brand? (4)
carbamazepine
phenytoin
phenobarbital
primidone
CP3
Which antiepileptic drugs are listed under the category where the supply of a specific brand is based on clinical judgment? (11)
Valproate
lamotrigine
perampanel
retigabine
rufinamide
clobazam
clonazepam
oxcarbazepine
eslicarbazepine
zonisamide
topiramate
In the risk-based categories of antiepileptic drugs, which category deems it unnecessary to supply a specific brand? (7)
Levetiracetam
lacosamide
tiagabine
gabapentin
pregabalin
ethosuximide
vigabatrin
What risk is associated with ALL antiepileptic drugs regarding suicidal thoughts and behavior?
associated with a small increased risk of suicidal thoughts and behavior.
When should patients seek medical advice regarding symptoms related to suicidal thoughts and behavior after starting antiepileptic treatment?
Immediately
symptoms may occur as early as one week after starting treatment
What precaution should be taken regarding the withdrawal of antiepileptic drugs? (2)
Abrupt withdrawal should be avoided
Reduction in dosage should be gradual
(in the case of barbiturates, withdrawal of the drug may take MONTHS due to the significant risk of SEIZURE RECURRENCE)
What is the recommended approach for withdrawing antiepileptic drugs in patients on multiple medications?
Withdraw one drug at a time
What are the criteria for patients with epilepsy to be able to drive a motor vehicle? (2)
if they have been seizure-free for one year
or have established a 3-year period of asleep attacks without awake attacks
(excluding large goods or passenger carrying vehicles)
What cautionary advice does the DVLA provide regarding driving and medication changes or withdrawal of antiepileptic drugs? (2)
that patients should not drive during medication changes
or withdrawal of antiepileptic drugs
for 6 months
What are the antiepileptic drugs associated with an increased risk of teratogenicity during pregnancy? (6)
Valproate
phenytoin
primidone
phenobarbital
lamotrigine
carbamazepine
What is the highest risk antiepileptic drug associated with congenital malformations and long-term developmental disorders?
Valproate
Can valproate be used in pregnancy? (2)
NO
UNLESS there is no safer alternative
Valproate should not be used during pregnancy or female children, or women who can bear children
What is the recommendation regarding contraception for women of child-bearing potential who are taking antiepileptic drugs?
should be given advice about the need for an effective contraception method to avoid unplanned pregnancy.
What precautionary measure is advised to reduce the risk of neural tube defects during pregnancy?
Folate supplementation
is advised before conception and throughout the first trimester
What is the recommendation for women taking antiepileptic monotherapy regarding breastfeeding?
Women taking antiepileptic monotherapy should generally be encouraged to breastfeed
(but specialist advice should be sought if needed)
What should infants be monitored for if their mothers are taking antiepileptic drugs and breastfeeding? (4)
sedation
feeding difficulties
adequate weight gain
developmental milestones
What precaution should be taken to prevent withdrawal effects in infants if a mother suddenly stops breastfeeding while taking antiepileptic drugs?
important to avoid abrupt cessation of breastfeeding
When should serum-drug concentration monitoring be undertaken in breastfed infants?
if suspected adverse reactions develop.
What is antiepileptic hypersensitivity syndrome, and which antiepileptic drugs are associated with it? (2)
Antiepileptic hypersensitivity syndrome is a rare but potentially fatal syndrome associated with some antiepileptic drugs
including carbamazepine, lacosamide, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, primidone, and rufinamide.
What are simple partial seizures?
seizures where the individual remains fully conscious throughout
Describe complex partial seizures.
seizures where the individual loses awareness
and cannot remember what happened after the seizure has passed.
What characterizes absence seizures?
Absence seizures cause the person to lose awareness of their surroundings
typically for up to 15 seconds.
What physical manifestations occur during myoclonic seizures?
Myoclonic seizures cause jerking or twitching movements
in the arms, legs, or upper body
How do tonic-clonic seizures progress? (3)
Tonic-clonic seizures have two stages and last a few minutes
Initially, the body becomes stiff (tonic phase)
followed by twitching of the arms and legs (clonic phase).
What is considered a medical emergency in terms of seizure duration? (2)
Any seizure lasting longer than 30 minutes
or a series of seizures without regaining consciousness in between.
What is the therapeutic range for Carbamazepine?
4 to 12mg/L (20 to 50 micromol/litre).
What are some warning signs associated with Carbamazepine use? (5)
toxicity symptoms such as incoordination, blurred vision, double vision, drowsiness, nystagmus, ataxia, arrhythmias, nausea & vomiting, diarrhea, and hyponatremia
blood disorders (fever, sore throat, unexplained bruising or bleeding)
skin disorders (mouth ulcers, rash)
hepatic disorders (severe GI upset, fatigue, jaundice, dark urine)
Antiepileptic Hypersensitivity Syndrome (fever, rash, swollen lymph nodes).
How should Carbamazepine therapy be monitored? (4)
plasma concentration (after 2 weeks to ensure it’s within the therapeutic range)
full blood count
renal function
hepatic function
Why may the dose of Carbamazepine be different in those with impaired liver disease? (2)
as their metabolism of Carbamazepine is impaired
so the dose may need to be increased accordingly
How should doses of Carbamazepine be adjusted during pregnancy?
based on plasma-concentration monitoring.
What are some drug interactions associated with Carbamazepine? (4)
increased plasma concentration with acetazolamide, cimetidine, clarithromycin, and erythromycin.
Decreased plasma concentration can occur with phenytoin, rifabutin, and St. John’s Wort.
It reduces the plasma concentration of antipsychotics, corticosteroids, coumarins, eplerenone, estrogens, progestogens, and simvastatin.
Additionally, there’s a possible increased risk of convulsions when given with orlistat (this applies to all antiepileptics)
What are the side effects associated with IV infusion of fosphenytoin?
severe cardiovascular reactions (including asystole, ventricular fibrillation, and cardiac arrest)
Hypotension, bradycardia, and heart block have also been reported
What monitoring and precautions are recommended when administering IV fosphenytoin? (2)
DURING infusion:
monitor heart rate, blood pressure, and respiratory function
AFTER infusion:
continue monitoring for at least 30 minutes
What should be done if hypotension occurs when administering IV fosphenytoin? (2)
reduce its infusion rate
or stop it completely
What type of individuals should we reduce the dose or infusion rate of IV fosphenytoin in? (3)
elderly
renal impairment
hepatic imapirment
Which drugs can lead to an increased plasma concentration of Carbamazepine? (4)
Acetazolamide
cimetidine
clarithromycin
erythromycin
What drugs can lead to DECREASED plasma concentration of carbamazepine? (3)
Phenytoin
rifabutin
St. John’s Wort
Which types of medications does Carbamazepine reduce the plasma concentration of? (7)
antipsychotics
corticosteroids
coumarins
eplerenone
estrogens
progestogens
simvastatin
What is the potential risk when antiepileptics are administered with orlistat?
increased risk of convulsions
What safety concerns are associated with high doses of gabapentin oral solution in adolescents or adults with low body weight (39–50 kg)?
high dose means they may INGEST LEVELS of propylene glycol, acesulfame K, and saccharin sodium
THAT EXCEED the DAILY INTAKE limits recommended by the World Health Organization (WHO)
What symptoms in relation to blood disorders should patients and their carers be alert for when taking LAMOTRIGINE?
symptoms of bone-marrow failure
such as anaemia, bruising, or infection
What serious skin reactions can develop with lamotrigine, and within what timeframe? (2)
Stevens-Johnson syndrome and toxic epidermal necrolysis
can develop within the first 8 weeks of taking lamotrigine.
What factors are associated with an increased risk of serious skin reactions with lamotrigine?
taking valproate at the same time
starting off on a higher initial dose than recommended
rapid dose increases
When should withdrawal of lamotrigine be considered?
if rash
or signs of hypersensitivity syndrome develop
What is the therapeutic range for phenytoin?
10 to 20mg/L (or 40 to 80 micromol/litre)
What is the dose equivalence between phenytoin sodium and phenytoin base?
100mg of phenytoin sodium to 92mg of phenytoin base
is equivalent in therapeutic effect
Why is it important to consider the difference in phenytoin content when switching formulations?
because the difference between phenytoin sodium and phenytoin base may be clinically significant.
What are some warning signs that patients taking phenytoin should report to their doctor immediately?
nystagmus, double vision, slurred speech, ataxia, confusion, hyperglycemia, rash, toxic epidermal necrolysis, jaundice, GI pain, dark urine, bleeding, bruising, fever, mouth ulcers, sore throat, suicidal thoughts, and low vitamin D levels (which may lead to rickets in children or osteomalacia in adults) to their doctor immediately.
Which drugs can lead to increased plasma concentrations of phenytoin?
amiodarone, chloramphenicol, cimetidine, disulfiram, diltiazem, fluconazole, fluoxetine, miconazole, topiramate, trimethoprim, metronidazole, clarithromycin, and telithromycin.
Which drugs can reduce plasma concentrations of phenytoin?
Rifamycins, St. John’s Wort, theophylline, itraconazole, and ciclosporin
What should patients be monitored for during sodium valproate treatment?
patients should be monitored for liver dysfunction
especially in the first 6 months of treatment, particularly if they are on multiple antiepileptic therapies
liver changes usually transient- monitor every 6 months until return to normal
When should treatment with sodium valproate be discontinued?
abnormally prolonged prothrombin time persists
or if signs of toxicity such as persistent vomiting, abdominal pain, anorexia, jaundice, and loss of seizure control occur.
What adverse ocular effect is associated with topiramate?
acute myopia (short-sightedness) with secondary angle-closure glaucoma, typically occurring within 1 month of starting treatment.
Fluid build-up resulting in anterior displacement of the lens and iris has also been reported.
What actions should be taken if raised intra-ocular pressure occurs in a patient taking topiramate? (3)
tpiramate should be stopped as rapidly as feasible
specialist ophthalmological advice should be sought.
Appropriate measures to reduce intra-ocular pressure should be used
What adverse effect is associated with vigabatrin?
Visual field defects
Any new visual symptoms should be reported and reviewed urgently by an ophthalmologist
Test visual field BEFORE starting treatment and at 6-month intervals
If develop symtoms= withdraw gradually
The onset of symptoms can vary from 1 month to several years after starting treatment, and visual problems usually persist despite discontinuation.
How should benzodiazepines for anaesthesia be administered?
should only be administered by or under the direct supervision of experienced personnel
with adequate training in anaesthesia and airway management.
What should benzodiazepines, Z-drugs, Chlomethiazole, promethazine, and melatonin be used for?
as hypnotics
Which medications are categorized as anxiolytics? (4)
benzodiazepines
buspirone
meprobamate
barbiturates
How can the effects of benzodiazepine dependence and withdrawal be minimized?
Withdrawal symptoms include insomnia, anxiety, loss of body weight and appetite, tremor, and perspiration
Develop up to 3 WEEKS after stopping a LONG-acting drug benzodiazepine
Develop DAYS after stopping a SHORT-acting one.
Best to do gradual withdrawal: minimizes effects such as confusion, convulsions, and toxic psychosis.
For which conditions are intermediate-acting barbiturates recommended?
only recommended for severe intractable insomnia, in patients already taking barbiturates
Who should we avoid barbiturates in?
elderly
What are the indications for benzodiazepine use?
indicated for the short-term relief (two to four weeks only) of anxiety that is severe or disabling, occurring with or without insomnia.
They should be used to treat insomnia only when it is severe, disabling, or causing the patient extreme distress.
Which benzodiazepines are classified as short-acting? (5)
Temazepam
Oxazepam
Loprazolam
Lormetazepam
Lorazepam
(TOLLL)
What side effects are associated with benzodiazepine overdose? (5)
- drowsiness
- ataxia
- dysarthria
- nystagmus
- and occasionally respiratory depression and coma
Ataxia means without coordination. People with ataxia lose muscle control in their arms and legs
Dysarthria is where you have difficulty speaking because the muscles you use for speech are weak.
Nystagmus is a rhythmical, repetitive and involuntary movement of the eyes. It is usually from side to side, but sometimes up and down or in a circular motion.
Respiratory depression (hypoventilation) is when you breathe too slowly or shallowly, preventing proper gas exchange in your lungs
how can benzodiazepine overdose be treated?
Activated charcoal
can be given within 1 hour of ingesting a significant quantity of benzodiazepine
provided the patient is awake and the airway is protected
Why should benzodiazepines and Z-drugs be avoided in the elderly?
due to an increased risk of confusion leading to falls and injury.
What CNS stimulants are used for the management of ADHD?
Methylphenidate and atomoxetine
(Dexamfetamine and lisdexamfetamine are alternatives in children who do not respond to these drugs)
What should be monitored during atomoxetine therapy?
Pulse, blood pressure, psychiatric symptoms, appetite, weight, and height
should be recorded at the initiation of therapy, following each dose adjustment, and at least every 6 months thereafter.
ADDITIONALLY, monitoring for the appearance or worsening of anxiety, depression, or tics is advised, especially in patients with a history of seizures.
What rare risk is associated with atomoxetine?
hepatic disorders
Prompt medical attention should be sought in case of abdominal pain, unexplained nausea, malaise, darkening of the urine, or jaundice.
Is there a risk of suicidal ideation with atomexetine?
Yes
There is a risk of suicidal thoughts and behavior
Patients should report any clinical worsening, suicidal thoughts or behavior, irritability, agitation, or depression to their GP.
What action should be taken if tics occur during dexamfetamine and lisdexamfetamine therapy
should be discontinued
What is the recommended duration of treatment for bipolar disorder after the last manic episode?
Treatment should be long term
Treat for at least two years from the last manic episode,
But if have risk factors for relapse, treat for up to 5 years
What class of drug may be heloful in the initial management of agitation in bipolar disorder?
Acute benzodiazepines
Which atypical antipsychotic drugs are useful in acute episodes of mania and hypomania?
olanzapine
quetiapine
risperidone
What is the narrow therapeutic range for lithium?
The narrow therapeutic range for lithium is 0.4 to 1 mmol/L
with the lower end recommended for maintenance and elderly patients,
and the higher end 0.8 to 1 mmol/L for acute episodes of mania and relapse patients.
What are some warning signs of lithium toxicity that require immediate reporting and treatment withdrawal? (8)
include serum concentration over 2 mmol/L
increasing gastrointestinal disturbances (vomiting, diarrhea)
visual disturbances (blurred vision)
CNS disturbances (drowsiness, unsteadiness, confusion)
tremors
signs and symptoms of hypothyroidism
signs and symptoms of renal dysfunction
and signs and symptoms of benign intracranial hypertension (persistent headache and visual disturbance).
How often should serum lithium concentration be monitored?
weekly initially
then every 3 months once the dose becomes stable.
How frequently should renal function be monitored in patients taking lithium?
every 6 months
What is the recommended frequency for monitoring cardiac function in patients on lithium therapy?
every 6 months
How often should thyroid function be monitored in patients taking lithium?
every 6 months
What caution should be exercised regarding driving and skilled tasks for patients on lithium therapy?
Patients may experience impaired performance of skilled tasks, such as driving or operating machinery.
What interactions increase the risk of toxicity with lithium? (10)
ACE inhibitors
angiotensin-II receptor antagonists
loop diuretics
thiazides and related diuretics
NSAIDs
potassium-sparing diuretics
aldosterone antagonists
metronidazole
SSRIs
tricyclics
What drug interacts with lithium to increase the risk of ventricular arrhythmias?
amiodarone
Which medications increase the risk of neurotoxicity when taken with lithium? (5)
methyldopa
phenytoin
carbamazepine
diltiazem
verapamil
What precaution should be taken when changing the preparation of lithium?
When changing the preparation of lithium
the** same precautions as the initiation of treatment** should be observed
due to the varying bioavailability of different preparations.
What should be given to patients on initiation of lithium treatment?
A lithium treatment pack
Why should patients be kept on the same brand of lithium?
to maintain consistency in dosage and bioavailability
How can lithium toxicity be exacerbated?
by sodium depletion
important to maintain a constant and adequate intake of salt and water, especially during infections or hot weather.
What substances should be avoided while taking lithium?
NSAIDs (nonsteroidal anti-inflammatory drugs)
alcohol
What is the risk of stopping lithium suddenly?
Stopping lithium suddenly can increase the risk of relapse
should only be done under the guidance of a doctor.
What are the major classes of antidepressant drugs (3)
tricyclic and related antidepressants
selective serotonin reuptake inhibitors (SSRIs)
monoamine oxidase inhibitors (MAOIs)
Which class of antidepressants is considered first-line indepression due to better tolerance and safety in overdose?
Selective serotonin reuptake inhibitors (SSRIs)
Who are tricyclic antidepressants not effective in treating depression in
children
What is a risk associated with MAOIs?
MAOIs have dangerous interactions with some foods and drugs.
Why should St John’s Wort not be recommended for depression?
an enzyme inducer and interacts with many drugs
What risk is associated with all types of antidepressant therapy?
Hyponatremia (usually in the elderly) is a risk associated with all types of antidepressants, with SSRIs posing a higher frequency.
What are symptoms of hyponatremia? (3)
drowsiness
confusion
convulsions
What population is particularly monitored for suicidal behavior when undergoing antidepressant therapy?
in children, young adults, and patients with a history of suicidal behavior
particularly at the beginning of treatment or if the dose is changed.
What are the three main areas of symptoms in serotonin syndrome? (3)
neuromuscular hyperactivity (tremor, hyperreflexia, clonus, myoclonus, rigidity)
autonomic dysfunction (tachycardia, blood pressure changes, hyperthermia, diaphoresis, shivering, diarrhea)
altered mental state (agitation, confusion, mania).
Why are monoamine oxidase inhibitors (MAOIs) less common than tricyclics or SSRIs?
due to their dietary and drug interactions.
What dietary precautions should patients taking MAOIs follow? (4)
should eat only fresh foods, avoid stale or “going off” food
avoid foods containing tyramine, such as mature cheese, pickled herring, broad bean pods
avoid certain food extracts like Bovril®, Oxo®, and Marmite®
They should also avoid alcoholic drinks or low-alcohol drinks.
Why should other antidepressants not be started for 2 weeks after stopping MAOIs?
to avoid the risk of serotonergic adverse effects.
What are the potential withdrawal symptoms of MAOIs? (11)
agitation
irritability
ataxia
movement disorders
insomnia
drowsiness
vivid dreams
cognitive impairment
slowed speech
hallucinations
paranoid delusions.
How should cessation of MAOIs be managed?
by slowly tapering the dose over at least 4 weeks
Which selective serotonin re-uptake inhibitors (SSRIs) are not recommended for individuals under 18? (6)
Citalopram
escitalopram
paroxetine
sertraline
mirtazapine
venlafaxine
Which SSRI has been shown to be effective for use in children and adolescents?
Only fluoxetine
What are some cautions associated with SSRIs? (7)
epilepsy (avoid if poorly controlled, discontinue if convulsions develop)
cardiac disease
diabetes mellitus
susceptibility to angle-closure glaucoma
history of mania
history of bleeding disorders (especially gastrointestinal bleeding)
if being used with other drugs that increase the risk of bleeding.
What are symptoms of poisoning from an SSRI overdose? (8)
nausea
vomiting
agitation
tremor
nystagmus
drowsiness
sinus tachycardia
convulsions
Rarely, severe poisoning results in the serotonin syndrome, with marked neuropsychiatric effects, neuromuscular hyperactivity, and autonomic instability