Question

Priyanka, a 65-year old female suffering from late-stage Parkinson’s disease, has been experiencing severe nausea and vomiting after a para-umbilical hernia surgery. Given the costs involved, her doctor has decided on a dopamine antagonist anti-emetic. She is currently taking a levodopa-carbidopa mixture and pramipexole. Over the course of her anti-Parkinson’s disease treatment, she has steadily become more reliant on online shopping.

a. Suggest an appropriate anti-emetic she can use. Justify your selection.

b. Explain how the anti-emetic will reduce nausea and vomiting.

c. Discuss why carbidopa is administered together with levodopa.

d. Explain how her pharmacotherapy aggravated her online shopping.

Answer 1

Reduction in dopamine levels in one's brain can worsen Parkinson's disease in a patient, even though the cause of the disease is unknown. And, during treatment of this disease the patient might feel nausea. So, to avoid vomiting sensation anti-emetic drugs can be suggested.

a. Anti-emetic that does not increase the Parkinson's disease as well it's symptoms like tremor and mobility etc is the best for the patient. So, a dopamine antagonist domperidone, which can block the movement of dopamine from brain to other parts of the body, through blood brain barrier. And, this whole mechanism of this drug occurs by making it not crossing the blood brain barrier which is might not lead to other disadvantages caused by usual anti-emetic drugs.

b. Nausea or vomiting might occur due to release of serotonin from serotonin receptors. These receptors are blocked by serotonin antagonists or anti-emetic drugs. These drugs can be given as intravenous and oral supplement.

c. For Parkinson's disease, levodopa and carbidopa is given combined to increase the efficiency of the former. This is because, levodopa might get converted into dopamine, before even entering into brain, through blood brain barrier which can cause increase in dopamine outside the brain. And, carbidopa which does not enter the barrier, help in making levodopa stable, during it's mechanism. So, further increase in dopamine in the other body organs is avoided by combination of levodopa and carbidopa.

d. During the course of anti-Parkinson's disease treatment, dopamine level go high, which can lead to development in mood and more of it can even lead to some addiction like over eating, shopping and coffee etc,. So, dopamine increase in this patient caused reliant behaviour in her and increased the urge to shop more. This occurs due to dopaminergic medication to prevent Parkinson's disease for the long term benefit and the exact reason for such behavioral changes is still unknown and such addiction varies from one person to another.