Parkinsonism Overview

<p>Less levodopa is available to penetrate the blood-brain barrier. (A)</p> Signup and view all the answers

<p>Nausea and vomiting. (D)</p> Signup and view all the answers

<p>Minimize the fluctuations in motor control. (C)</p> Signup and view all the answers

<p>Ischaemic heart disease (D)</p> Signup and view all the answers

<p>Abolishes the therapeutic effect of levodopa. (A)</p> Signup and view all the answers

<p>2–3 g (C)</p> Signup and view all the answers

<p>They reduce systemic concentration of DA. (A)</p> Signup and view all the answers

<p>Extrapyramidal motor disorder (B)</p> Signup and view all the answers

<p>Reserpine (B)</p> Signup and view all the answers

<p>Finding that levodopa could produce significant improvement (B)</p> Signup and view all the answers

<p>Excitotoxic neuronal death (A)</p> Signup and view all the answers

<p>Parkinson's disease (PD) (B)</p> Signup and view all the answers

<p>Severe vomiting (D)</p> Signup and view all the answers

<p>To decrease the dosage of levodopa required (A)</p> Signup and view all the answers

<p>1.25 mg once at night (B)</p> Signup and view all the answers

<p>Postural hypotension (C)</p> Signup and view all the answers

<p>They have negligible affinity for D1 and nondopaminergic receptors. (C)</p> Signup and view all the answers

<p>Rapid and unpredictable fluctuations in motor control occur. (B)</p> Signup and view all the answers

<p>It reduces the need for higher doses of levodopa. (C)</p> Signup and view all the answers

<p>Older age can increase the risk of adverse effects. (B)</p> Signup and view all the answers

<p>It stimulates peripheral decarboxylation of levodopa. (B)</p> Signup and view all the answers

<p>0.25 g taken twice daily after meals. (A)</p> Signup and view all the answers

<p>0.4–0.8 g (C)</p> Signup and view all the answers

<p>Ropinirole offers similar symptomatic relief compared to levodopa. (A)</p> Signup and view all the answers

<p>Pramipexole shows a similar side effect profile but is better tolerated. (A)</p> Signup and view all the answers

<p>Patients have diminished capacity to synthesize, store, and release DA. (A)</p> Signup and view all the answers

<p>It can often be achieved in 1–2 weeks. (B)</p> Signup and view all the answers

Reduction in the ability to initiate and execute voluntary movements, seen in Parkinson's disease.

Increased muscle tone, a symptom of Parkinson's disease.

Involuntary rhythmic shaking or tremor, a hallmark sign of Parkinson's disease.

The process where a drug is broken down and eliminated from the body.

The first pass effect is the significant reduction of a drug's concentration before reaching systemic circulation.

The 'on-off' effect in Parkinson's disease refers to unpredictable fluctuations in motor control, characterized by periods of good mobility ('on' phase) alternating with periods of stiffness and slowness ('off' phase).

Levodopa is a precursor to dopamine, a neurotransmitter crucial for movement control. It helps improve motor function in Parkinson's patients by increasing dopamine levels in the brain.

Peripheral decarboxylase inhibitors, like carbidopa and benserazide, block the breakdown of levodopa in the body, making more of it available to reach the brain.

Pyridoxine, also known as Vitamin B6, can worsen Parkinson's symptoms when taken with Levodopa. It enhances the breakdown of Levodopa in the body, reducing its effectiveness. This is why it's not used in combination with Levodopa treatment.

The half-life (t½) of a drug refers to the time it takes for the concentration of the drug in the body to reduce by half. For Levodopa, peripheral decarboxylase inhibitors like carbidopa increase its half-life, meaning it stays in the body longer.

A progressive neurological disorder primarily affecting older individuals, characterized by tremors, rigidity, slow movements (bradykinesia), and postural instability. Primarily caused by a deficiency of dopamine in the brain.

The gradual degeneration of neurons in the substantia nigra pars compacta (SN-PC) and the nigrostriatal (dopaminergic) tract, resulting in a depletion of dopamine in the basal ganglia.

The process of neuronal death caused by an excessive accumulation of the excitatory neurotransmitter glutamate, particularly through NMDA receptors, leading to toxic levels of calcium.

A drug-induced condition mimicking Parkinsonism, often due to the use of medications like antipsychotics (neuroleptics) and antiemetics (metoclopramide), which block dopamine receptors.

The precursor to dopamine, which is converted to dopamine in the brain. Used to treat Parkinson's disease by increasing dopamine levels.

Pramipexole, ropinirole, and bromocriptine are dopamine agonists used to treat Parkinson's disease. They mimic dopamine's effects in the brain, improving motor function.

Dopamine agonists like pramipexole and ropinirole are often used as monotherapy for early-stage Parkinson's, potentially delaying the need for levodopa.

Dopamine agonists like pramipexole have a higher affinity for D3 receptors compared to other agonists, leading to a more potent effect on movement control.

Pramipexole and other dopamine agonists are generally well-tolerated with fewer gastrointestinal side effects compared to bromocriptine, making them a preferred choice for some patients.

Pramipexole and ropinirole can be used as supplementary drugs to levodopa in advanced Parkinson's, helping to manage symptoms and improve quality of life.

Combining levodopa with a decarboxylase inhibitor, like carbidopa, is a standard approach for treating Parkinson's disease, except when the patient experiences significant involuntary movements with the combined therapy.

The combination of levodopa and carbidopa is widely known as "co-careldopa". This combination is a standard treatment for Parkinson's disease, with the exception of cases where it triggers significant involuntary movements.

Ropinirole and pramipexole are two non-ergoline, selective D2/D3 receptor agonists, meaning they specifically target dopamine receptors (D2 and D3) and have minimal interaction with D1 and other non-dopaminergic receptors.

Bromocriptine, though largely replaced by newer dopamine agonists like ropinirole and pramipexole, can be used as a supplemental treatment with levodopa in late-stage Parkinson's disease to improve control and reduce 'on-off' fluctuations.

Although bromocriptine is a dopamine agonist, it has largely been replaced by ropinirole and pramipexole due to its potential for significant side effects, including vomiting, hallucinations, hypotension, nasal stuffiness, and conjunctival injection.