Chapter 4 – Nervous System
DEMENTIA Dehydration – interrupt Tx if this occurs from
prolonged vomiting or diarrhoea
Centrally Acting
Administration: apply to clean, dry, non-hairy,
Anticholinesterases non-irritated skin on back, upper arm or chest,
removing after 24hrs and replace on a different
Donepezil (Aricept)
area (avoid same area for 14 days)
Action – reversible Achesterase inhibitor
CAL: take with food
Indication: mild-to-mod dementia in AD
NMDA Receptor Antagonists
Dose: initially 5mg ON for 1 month then
increased if necessary up to 10mg ON (start low Memantine
and increase if tolerated and necessary)
Indication: moderate to severe dementia in AD
!: asthma, COPD, peptic ulcers
!: epilepsy, H/O convulsions
SEs: aggression, reduced appetite, muscle
SEs: constipation, drowsiness, hypertension
cramps, urine incontinence, bradycardia
Administration: place orodispersible tab on EPILEPSY
tongue, allow to disperse then swallow
Anti-Epileptics
Galantamine (Reminyl, Gazylan XL) - brivaracetam, eslicarbazepine, oxcarbazepine,
rufinamide, stiripentol
Action - reversible Achesterase inhibitor with
nicotinic receptor agonist properties Ethosuximide
Serious skin reactions – incl. SJS and acute Indications: absence and myoclonic seizures
generalised exanthematous pustulosis.
Discontinue at first sign of a rash. Advice – report blood disorders (fever, rash,
mouth ulcers, bruising or bleeding). Blood
CAL: take with food or post-meal. Also, causes counts are required if fever, sore throat, mouth
sleepiness hence avoid alcohol, etc ulcers, bruising or bleeding occurs
Rivastigmine (Exelon) Fosphenytoin (Pro-Epanutin) (PARENTERAL)
Action – reversible non-competitive Dose – 1.5mg FP sodium = 1mg phenytoin
Achesterase inhibitor
Perampanel (Fycompa)
Indications: mild to mod dementia in AD and
Parkinson’s disease Indications: focal seizures +/- 1°/2° generalised
TC seizures
Dose equivalence – when switching from PO to
transdermal, if taking 3-6mg PO, switch to Dose adjustments – titrate at intervals of at
4.6mg/24hrs patch, then titrate. If taking 9mg least 1 week with concurrent CZP,
PO, switch to 9.5mg/24hrs patch (lower fosphenytoin, oxcarbazepine or phenytoin
strength patch if not tolerated). If taking 12mg Dispensing – maintain on same brand/generic
PO, switch to 9.5mg/24hrs patch. Apply 1st
patch on the day following last oral dose.
SEs: weight loss, hyperhidrosis, incontinence
,Chapter 4 – Nervous System
Carbamazepine (Tegretol, Carbagen SR) Gabapentin (Neurontin) – CD-3
Indications: Indications:
1. Focal and 1°/2° generalised TC seizures 1. Focal seizures (+/- 2° generalisation)
2. Trigeminal neuralgia 2. Peripheral neuropathic pain
3. Bipolar disorder unresponsive to lithium 3. Migraine prophylaxis
4. Acute alcohol withdrawal (adjunct) 4. Menopausal symptoms
5. Diabetic neuropathy
MHRA/CHM (2017) – risk of severe respiratory
!: consider vitamin D supplements in long-term depression; higher risk in Pts with poor
immobilised Pts or those with inadequate sun respiratory function, renal impairment, elderly
exposure or dietary calcium intake and with use of CNS depressants
Blood, hepatic or skin disorders – withdraw if MHRA/CHM (2019) – risk of abuse and
aggravated liver disease or leucopenia occurs dependence; hence re-classified as Schedule 3
CD (exempt from safe custody)
!: absence/myoclonic seizures (exacerbation)
M: signs of gabapentin abuse
SEs (dose-limiting) – incl. headache, ataxia,
drowsiness, N/V, blurred vision, dizziness and Administration – caps can be opened but bitter
allergic skin reactions taste is difficult to mask
SEs: tic, tremor, weight gain, drowsiness CAL:
Avoid indigestion remedies < 2hrs of dose
Allergy – associated with antiepileptic
Causes sleepiness
hypersensitivity syndrome
Do not stop taking unless asked to
Pre-Tx screening – test for HLA-B*1502 allele in
Lacosamide (Vimpat)
individuals of Han Chinese or Thai origin
M: plasma conc. for optimum response is Indications: focal seizures (+/- 2° generalisation)
between 4-12mg/L (20-50mmol/L) after 2wks X: AV block
Cessation: in bipolar disorder, reduce dose Allergy – associated with antiepileptic
gradually over at least 4 weeks hypersensitivity syndrome
Administration – oral liquid can be used rectally Levetiracetam (Keppra)
– retain for at least 2 hours
Indications:
Dispensing: maintain the same brand
1. Focal seizures with or without 1°/2°
Advice – report blood, skin or hepatic disorders generalised TC seizures
(fever, rash, mouth ulcers, bruising or bleeding) 2. Myoclonic seizures and TC seizures
CAL: do not stop CZP and can cause sleepiness SEs: anxiety, drowsiness, movement disorders
Lamotrigine (Lamictal)
, Chapter 4 – Nervous System
Indications: Overdose = nystagmus, diplopia, slurred
1. Focal seizures (+/- valproate) speech, ataxia, confusion and hyperglycaemia
2. 1°/2° generalised TC seizures
Allergy – cross-sensitivity reported with CZP
3. Seizures associated with Lennox-Gastaut
4. Bipolar disorder (+/- valproate) Pre-Tx screening: HLAB*1502 allele in
individuals of Han Chinese or Thai origin
!: myoclonic seizures, Parkinson’s
M: total plasma-phenytoin concentration for
Serious skin reactions – incl. SJS and TEN. Most
optimum response is 10-20mg/L
rashes occur in the first 8 weeks. Consider
(40-80mmol/L). Interpret concentration
withdrawal if rash or hypersensitivity occurs.
carefully in pregnancy, elderly and certain
Increased risk with use of valproate, high initial
disease states where protein binding is reduced.
dosing of lamotrigine and rapid dose increase.
Dispensing – maintain on same brand/generic
Allergy – associated with antiepileptic
hypersensitivity syndrome Advice: report fever, rash, mouth ulcers,
bruising or bleeding – blood or skin disorders
Cessation – avoid abrupt withdrawal (taper off
over 2 weeks or longer) unless serious skin Pregabalin (Alzain, Lyrica) – CD-3
reaction occurs
Indications:
Dispensing – maintain on same generic/brand 1. Peripheral and central neuropathic pain
Advice: 2. Focal seizures +/- 2° generalisation
1. Skin reactions – report rash/hypersensitivity 3. Generalised anxiety disorder
2. Blood disorders – report bone marrow MHRA/CHM (2019): risk of abuse and
failure (anaemia, bruising, infection) dependence – reclassified as a Class C
Phenytoin (Epanutin) substance and a Schedule 3 CD
SEs: infection, vertigo, drowsiness, joint
Indications:
disorders, oedema, speech impairment
1. Tonic-clonic and focal seizures
2. Seizures during or following head injury M: signs for pregabalin abuse
3. Status epilepticus
Cessation – taper over at least 1 week
Equivalence: 100mg phenytoin Na = 92mg base
Safety information (2016) – risk of death or
severe harm from error with injectable use
!: enteral feeding – interrupt feeding for 2hrs
before and after dose
Vitamin D supplements – consider in long-term
immobilised Pts, those with inadequate sun
exposure or dietary intake of calcium
Rash – discontinue. If mild, re-introduce.
Bradycardia and hypotension – with IV use.
Reduce rate of administration if it occurs Sodium Valproate (Epilim, Episenta)