Parkinson's disease pharmacology Flashcards
What is dopamine dysregulation syndrome and impulse control syndrome?
Dopamine agonists can cause dopamine dysregulation syndrome and impulse control syndrome.
Dopaminergic dysregulation syndrome — Compulsive use of dopaminergic drugs develops in a small number of patients with PD. typically involves male patients with early onset PD who take increasing quantities of dopaminergic drugs despite increasingly severe drug-related dyskinesia. DDS can be associated with a cyclical mood disorder characterized by hypomania or manic psychosis.
A form of complex, prolonged, purposeless, and stereotyped behavior called punding also may be associated with DDS [80].
Impulse control disorders — Dopamine (DA) agonist therapy is associated with an increased risk of impulse control disorders including pathologic gambling, compulsive sexual behavior, or compulsive buying. Impulse control disorders including hypersexuality and pathologic gambling may accompany DDS [78].
What is the cheese reaction?
“Because gastrointestinal monoamine oxidase (MAO) effectively prevents dietary pressor amines, typically tyramine, from entering the tissues, a marked hypertensive response (the ““cheese reaction””) can occur when subjects treated with antidepressant MAO inhibitors ingest foods or beverages rich in such amines. This is due to the potentiation of sympathomimetic activity of ingested tyramine present in cheese and other food stuff, resulting from its ability to release noradrenaline, when prevented from
metabolism by MAO. Selegiline (a preferential MAO-B inhibitor) has no MAO-A inhibition at 10 mg/d or less, but at 20 mg/D or above it loses this specificity.”
What is the mechanism of action of entacapone?
Inhibition of catechol-O-methyltransferase (COMT) prolongs the action of dopamine by inhibiting its metabolism. Clinical trials have shown reduction of the wearing off effect in parkinsonian patients treated with tolcapne and entacapone. The other agents listed are dopamine receptor agonists.
How does DBS work?
“High-frequency stimulation of the subthalamic nucleus in Parkinson disease (PD) usually relieves the same
signs and symptoms of PD as does levodopa, and to the same extent, but without the same side effects,
especially dyskinesias.”
