CNS Flashcards
What drugs are used for nausea and vomiting in pregnancy
- Cyclizine
- Metoclopramide or Prochlorperazine
What is used in motion sickness
- Hyoscine hydrobromide
- Promethazine if sedative effect required (or cyclizine / cinnarizine)
What is used in post operative nausea and vomiting
- Ondanseron
- Dexamethasone
- Droperidol & haloperidol
- Prochloperazine
- Cyclizine - N&V caused by opioid or general anaesthetics
Side effect of domepridone
Risk of cardiac side effects
Max treatment duration should not exceed 7 days
Side effect of metoclopramide
Risk of neurological adverse effects
Short term use up to 5 days
What age can Promethazine not be sold OTC
Children < 6 yrs for cough and cold
Pain ladder
Step 1: Mild pain
- Non-opiods - paracetamol, aspirin, NSAIDs
Step 2: Mild to Moderate pain
- Weak opioids - codeine, tramadol
Step 3: Moderate to Severe
- Strong opioid - morphine, oxycodone, methadone, fentanyl
Adjuvants:
• neuropathic pain → TCA, gabapentin / pregablin
• bone metastases → bisphosphonates, strontium ranelate
• nerve compression by tumors → dexamethasone
What is used in mild to moderate Alzheimer’s
- Donepazil
- Galantamine
- Rivastigmine
What is used in severe Alzheimer’s
Memantine
What is used in non-alzheimer’s with lewy bodies
Donepazil
Rivastigmine
If not tolerated: galantamine
What is used in severe dementia with Lewy bodies
Donepazil
Rivastigmine
What is used to treat extreme violence, aggression and agitation in dementia
- Oral IM haloperidol
- Olanzapine
- Lorazepam
What is used in dementia with Lewy body (Parkinson’s disease)
Rivastigmine
Can you use Acetylcholine inhibitors and memantine in pts with frontotemporal dementia or cognitive impairment caused by sclerosis
No
Side effect associated with Donezapil
Neuroleptic malignant syndrome
high fever, sweating, unstable blood pressure
Side effect associated with Rivastigmine
- Dehydration
- GI side effects - STOP/ Switch to patch
When to stop Rivastigmine
GI side effects
switch to patch
Side effect of Galantamine
Stevens Johnson’s Syndrome
How do we treat Focal seizures
- 1st: Lamotrigine or Levetiractem
- 2nd: Carbamazapine. Oxcabazepine, zonisamide
How do we treat Tonic-clonic seizures
Valporate Alt. Lamotrigine or Levetiracetam
How do we treat Absence seizures
Ethosuximide or Valporate
Alt. Lamotrigine or Levetiracetam
How do we treat Myoclonic seizures
Valporate Alt. Topiramate, Levetiracetam
How do we treat Atonic/tonic seizures
Valporate Alt. Lamotrigine
What are category 1 anti-epileptic drugs
’CP3’
- Carbamazepine
- Phenytoin
- Phenobarbital
- Primidone
Prescribed by brand
What are category 2 anti-epileptic drugs
‘TV Loan @ Currys’
- Valporate
- Lamotrigine
- Clonazepam
- Topiramate
What are category 3 anti-epileptic drugs
- Levetiractem
- Gabapebtin
- Pregablin
- Ethosuximide
How are anti-epileptic drugs withdrawn
- Gradually reduce dose with supervision
- avoid abrupt withdrawal
- withdraw one drug at a time
How long is the driving ban after last dose of anti-epeleptic (withdrawal)
6 months
How long is the driving ban after first unprovoked seizure
- normal car
- large vehicles
- 6 months
- 5 years for large vehicles
How long must patient be seizure free to drive
1 year
How long are patients not allowed to drive for if they have seizures while asleep
1 year
How long are patients not allowed to drive for if they have seizures while asleep and awake
3 years
What anti epileptic are associated with anti epileptic hypersensitivity syndrome
‘CP3RLOL’
- carbamazepine
- phenobarbital
- phenytoin
- Primidone
- rufinamide
- lamotrigine
- oxcarbazepine
- lacosamide
MHRA warning with antiepileptics
Suicidal thoughts
Antiepileptic drugs with highest teratogenic risk
Valproate
Antiepileptic with increased risk of teratogenicity
‘CP3’
- carbamazepine
- phenytoin
- Phenobarbital
- primidone
Which drug is associated with cleft palate
Topiramate (1st trimester)
What antiepileptic drugs require monitoring of fatal growth
tira
Levetiracetam and topiramate
What dose and duration should folic acid be given to women at high risk of conceiving a child with neural tube defects
5 mg OD
before conception and until 12th week
Withdrawal effects in new-borns occur more with?
Benzodiazepines and phenobarbital
What antiepileptics are found in high concentration in breast milk
‘ZELP’
- zosinamide
- ethosuximide
- lamotrigine
- primidone
What antiepileptics accumulate in infants
Lamotrigine
Phenobarbital
What antiepileptics inhibit sucking reflex
Phenobarbital
Primodine
Symptoms of antiepileptic hypersensitivity syndrome
• what to do if this occurs?
Rash, fever, lymphadenopathy, systemic involvement
- occurs in first 1-8 weeks of starting
- discontinue immediately
Which antiepileptic is associated with severe skin reactions especially in children
Lamotirigine
What drug increases lamotrigine side effects and why?
Sodium valproate
Enzyme inhibitor so increases concentration of lamotrigine
What two antiepileptics are at risk of cross-sensitivity
Carbamezapin
Phenytoin
Side effect of gabapentin
Severe respiratory depression
What antiepileptics are associated with blood dyscrasias
’C Vet Plz’
- carbamazepine
- valproate
- ethosuximide
- topiramate
- phenytoin
- lamotrigine
- zonisamide
report signs of infection, bruising, bleeding
What antiepileptics are associated with eye problems
Vigabatrin
Topiramate
What antiepileptics are associated with encephalopathic symptoms
sedation, super and confusions
Vigabatrin
Topiramate
Valproate
Nature of interaction between valproate and digoxin
Increase plasma conc.
Increased toxicity
Nature of interaction between carbamazepine and phenytoin
Decreased concentration of carbamazepine
What is used to treat Diavet syndrome
Valporate
OR
‘CVS’
Clobazam + valproate + stiripentol
Which anetylchorinesterase inhibitor is avoided in hepatic and renal impairment <9ml/min
Galantine
What are the acteyl chloringenic side effects?
dementia drugs
‘Dumbbels’
Diarrhoea
Urination
Muscle cramps
Bronchospasm
Bradycardia
Emesis (vomiting)
Lacrimation (teary eyes)
Salivation / sweating
Monitoring requirement for rivastigmine
Body weight
Side effect of memantine
Constipation
When to avoid phenytoin
- Absence seizures
- myoclonic seizures
Exarcebates
Therapeutic range of phenytoin
10-20 mg/L
6 -15 mg/l in neonates
What to look out for in phenytoin toxicity
‘SNACHD’
- slurred speech
- nystagmus (uncontrolled eye movement)
- ataxia (lack of voluntary coordination of movement)
- confusion
- hypERglycaemia
- diploma (double vision), blurred vision
Side effects of phenytoin
Long term: change in appearance
- low vitamin D
- hepatic toxicity
When to discontinue phenytoin
Signs of liver toxicity
Nature of interaction between phenytoin and Amiodarone
Increase concentration of phenytoin
Nature of interaction: phenytoin and St. John’s wort
Decrease concentration of phenytoin
Nature of interaction: phenytoin and quinones
Anticonvulsant effect antagonised
Nature of interaction: phenytoin and contraceptives
Reduce plasma conc. Of contraceptive
When to avoid carbamazepine
- atonic seizure
- clonic seizure
- myoclonic seizure
Therapeutic range of carbamazepine
4-12 mg/l
Monitor after 1-2 weeks
Signs of toxicity with carbamazepine
‘I HANDBAG’
- inco-coordination
- hypONatraemia
- ataxia
- nystagmus
- drowsiness
- blurred vision
- arrhythmias
- gastro - intestinal disturbance
Nature of interaction: carbamerapine and SSRI
Hyponatramia
Nature of interaction: carbamerapine and valproate
Hepatotoxicity
Nature of interaction: carbamerapine and fluoxetine
Increase conc. Of carbamazepine
How often should liver function be monitored with valproate
Every 6 months
How is status epilepticus treated
• Urgently with lV lorazepam
• repeat once after 10 minutes if no response
Rectal Diazepam or buccal mudazolam - community
What is avoided in status epilepticus
IV diazepam
If patient has a seizure after treatment with benzodiazepine in status epilepticus, what should be given?
‘Ph=F’
- phenytoin
- Phenobarbital
- fosphenytoin
What is given first line in febrile convulsions
Paracetamol
What is used to treat convulsive seizures of febrile convulsions lasting more than 5 minutes in community setting
- Diazepam rectally
- midazolam solution (in the buccal cavity)
Repeat once after 10-15 minutes if necessary
What is used in chronic anxiety?
Antidepressant (SSRI)
What are the hypnotic drugs
- Benzodiazepines
- z-drugs
- chlomethiazole
- promethazine
- melatonin
Examples of benzodiazepines
Lorazepam
Diazepam
Benzodiazepines metabolised by the liver
‘Found A CD in the liver**’
- Florazepam
- alprazolam
- cholerdiazepoxide
- diazepam
What benzodiazepines are not affected by the liver
‘This LOT are not metabolised by liver’
- lorazepam
- Oxazepam
- temazepam
Side effect of benzodiazepine in elderly
Hypotension
Benzodiazepine in pregnancy
Neonatal depression (floppy syndrome)
When are benzodiazepines contraindicated
Respiratory distressed patients
Benzodiazepine and alcohol
Enhances side effects
What route can’t Benzos be given
Intramuscularly - eratic absorption at site
What antiemetic is given for chemically induced nausea and vomiting (most drugs including opioids)
Haloperidol
Oral: 1.5mg ON/BD, titrate up to a max of 10mg daily
How is oxycodone immediate release prescribed?
QDS
What is used to test for cognitive impairment
MMSE
MoCA
Side effects of valproate
GI
Weight gain
What electrolyte imbalance puts patient at high risk of lithium toxicity
HypONatraemia - low sodium
Side effect of benzodiazepines and z-drugs (urine)
Reduce awareness of the need to urinate
Drugs that have antimuscarinic effects (anticholinergic)
- Tricyclic Antidepressants (eg. Amitriptyline, dosulepin)
- Antihistamines *(eg. Chlorphenamine and Promethazine)
- Antipsychotic (eg. Olanzapine and quetiapine)
- Urinary antispasmodic (eg. Solifenacin and tolterodine)
When should rivastigmine be reviewed
Dehydration resulting from prolonged vomiting or diarrhoea
Antipsychotic and elderly dementia patients
MHRA: increased risk of stroke and small increased risk of death
What class and schedule are gabapentin and pregabalin
Class 3 Schedule 3
Nature of interaction: phenytoin and anti-folate
Methotrexate and trimethoprim
Increased anti-folate effect
Side effects of benzodiazepines
- Paradoxical increase in hostility and aggression
- Sedation
- Dependence
Signs of benzodiazepines overdose
- Ataxia
- Nystagmus
- Drowsiness
- Respiratory depression
- Coma
- Hangover effect when taken at night
What is used to treat benzodiazepine poisoning
Flumenazel
Withdrawal process of benzodiazepines
- Transfer to equivalent daily dose of diazepam preferably taken at night for 1 week
- Reduce diazepam dose by 1-2mg every 2-4 weeks
- Reduce the dose further then stop
Withdrawal symptoms for long term users usually resolve within 6-18 months of the last dose
What benzodiazepine is used in conscious sedation in dental procedures
Temazepam