You are a medical student based in the memory clinic. An 83-year-old female attends. She is on memantine. What is the mechanism of this medication?
NMDA Antagonist
Memantine is a clinically useful drug in many neurological disorders, including Alzheimer’s disease. The principal mechanism of action of memantine is believed to be the blockade of current flow through channels of N-methyl-d-aspartate (NMDA) receptors - a glutamate receptor subfamily broadly involved in brain function.
What are some side effects of anti-psychotics? (11)
Metabolic syndrome.
Hyperprolactinaemia (galactorrhea, impaired glucose tolerance).
Dystonia.
Dyskinesia.
Antiemetic effects.
Extra-pydradimal side effects.
Antimuscarinic (dry mouth, blurred vision, urinary retention, constipation).
Sedation.
Weight gain.
Neuroleptic malignant syndrome (pyrexia, muscle stiffness).
Reduced seizure threshold (greater risk with atypical).
What is a potential complication of anti-psychotic medication?
Long QT syndrome.
What is the mechanism of action of anti-psychotic medications.
Act as dopamine D2 receptor antagonists, blocking dopaminergic transmission in the mesolithic pathways.
What class of drug is clozapine.
Atypical anti-psychotic.
What are some extra-pyramidal side effects of anti-psychotic medications? (4)
Parkinsonism.
Acute dystonia (e.g. torticollis, oculogyric crisis).
Akathisia (severe restlessness).
Tardive dyskinesia (late onset of choreoathetoid movements, abnormal, involuntary, may occur in 40% of patients, may be irreversible, most common is chewing and pouting of the jaw)
What percentage of patients on anti-psychotic medication experience tardive dyskinesia?
Approximately 40% of patients.
What are the dangers with anti-psychotic medication in elderly patients? (2)
Increased risk of stroke.
Increased risk of venous thromboembolism.
What is the most likely anti-psychotic to cause long QT syndrome?
Halperidol