dementia

Question 1

Donepezil

Indications

Answer 1

• Mild to moderate dementia in Alzheimers disease

Question 2

Donepezil

MOA

Answer 2

• Specific and reversible inhibitor of acetylcholinesterase

Question 3

Donepezil

Warnings

Answer 3

• Cautioned in
  
  • Asthma
  • COPD
  • Sick sinus syndrome
  • Supraventricular conduction abnormalities
  • Susceptibility to peptic ulcers
  • Elderly- in patients with known persistent bradycardia (<60bpm)

Question 4

Donepezil

Adverse effects

Answer 4

• GI disorders- N&V, GI bleed/ulcers
• Psychiatric disorders- hallucinations, aggitation, abnormal behaviour
• Nervous system- Insomnia, SYNCOPE
• Can impair driving performance (fatigue, dizziness, cramps)

Question 5

Donepezil

Interactions

Answer 5

• CYP inhibitors
• CYP inducers
• Block the action of anticholinergic drugs (e.g. hyoscine, atropine)
• Synergistic activity with treatments involving neuromuscular blocking agents, cholinergic agonists, BB that have an effect on cardiac conduction

Question 6

Rivastigmine

Indications

Answer 6

• Mild to moderate dementia in alzheimers disease
• Mild to moderate dementia in PD

Question 7

Rivastigmine

Dose equivalence

Answer 7

• Important to note the conversion for PO to transdermal
• 3-6mg PO = 4.6mg/24hrs then titrate
• 9mg PO = 9.5mg/24hrs
• If patients on PO are not tolerating or stable then switch to a patch

Question 8

Rivastigmine

MOA

Answer 8

• Rivastigmine is an acetyl and butyrylcholinesterase inhibitor thought to facilitate cholinergic transmission by slowing the degradation of acetylcholine released by cholinergic neurones
• Thus, rivastigmine may have an ameliorative effect on cholinergic-mediated cognitive deficits in dementia associated with alzheimers disease
• NB- Galantamine is also a acetylcholinesterase inhibitor

Question 9

Rivastigmine

Warnings

Answer 9

• Bladder outflow obstruction
• Conduction abnormalities
• Duodenal ulcers
• Gastric ulcers
• Asthma
• Fatal overdose with patch admin errors
• History of seizures

Question 10

Rivastigmine

Adverse effects

Answer 10

• UTI
• Decreased appetites
• Anxiety, depression, delirium
• Syncope, headache
• Worsening of parkinsons

Question 11

Rivastigmine

Monitoring

Answer 11

• Patients with body weight <50kg may experience more side effects and more likely to discontinue
• Hepatic impairment

Question 12

Memantine

Indications

Answer 12

• Treatment of adult patients with moderate to severe alzheimers disease

Question 13

Memantine

MOA

Answer 13

• There is increasing evidence that malfunctioning of glutamatergic neurotransmission in particular NMDA-receptors contributes to both expression of symptoms and disease progression in neurodegenerative dementia
• Memantine is a voltage-dependent, moderate affinity uncompetitive NMDA-receptor antagonist
• It modulates the effects of pathologically elevated tonic levels of glutamate that may lead to neuronal dysfunction

Question 14

Memantine

Warnings

Answer 14

• Cautioned in
  
  • Epilepsy
  • History of convulsions
  • Risk factors for epilepsy

Question 15

Memantine

Adverse events

Answer 15

• Balance disorders
• HTN
• Dyspnoea
• Elevated LFTs
• Somnolence

Question 16

Memantine

Interactions

Answer 16

• L-DOPA, dopaminergic agonists and anticholinergics may be enhanced by concomitant treatment with NMDA-antagonists
• The effect of barbiturates and neuroleptics may be reduced
• Ketamine, dextromorphan due to the risk of pharmacotoxic psychosis