Anti Parkisonian Drugs Question And Answers

Anti Parkisonian Drugs Important Notes

Anti Parkinsonian Drugs Parkinsonism

  • It is an extrapyramidal motor disorder
  • Characterized by
    • Rigidity
    • Tremor
    • Hypokinesia
    • Excessive salivation
    • Dementia
  • Mainly occurs due to the degeneration of nigrostriatal neurons which are dopaminergic
  • Dopamine deficiency and cholinergic excess occur in it
  • Drugs used for it are
    • Levodopa – precursor of doapmine
    • Carbidopa and benserazide – prevent decarboxylation of levodopa

Anti Parkinsonian Drugs Long Essays

Question 1. Classify the drugs used in Parkinsonism. Discuss the pharmacology and adverse effects of L-dopa.


Anti-parkinsonian drugs:

  • These are drugs that have a therapeutic effect on Parkinsonism.

Anti-Parkisonian Drugs Classification:

1. Drugs affecting the brain’s dopaminergic system.

  • Dopamine precursor – levodopa (L-dopa).
  • Peripheral decarboxylase inhibitors – carbidopa, benserazide.
  • Dopaminergic agonists – bromocriptine, ropinirole.
  • MAO-B inhibitor – selegiline.
  • COMT (Catechol-O-methyl transferase) inhibitor – entacapone, touch.

Anti-Parkisonian Drugs Levodopa (L-Dopa):

  • Levodopa is the precursor of dopamine.

Levodopa Mechanism of action:

Levodopa crosses the blood-brain barrier.

It is taken up by pre-synaptic terminals of dopaminergic

Dehydroxylation occurs.

Causes the formation of dopamine.

Levodopa Actions:

1. CNS actions.

  • Causes hypokinesia and rigidity resolution.

2. CVS actions:

  • Causes tachycardia and postural hypotension.

3. CTZ [Chemoreceptor trigger zone]

  • Stimulates CTZ to induce vomiting.

4. Endocrine.

  • It acts on pituitary mamma tropes to inhibit prolactin release.

Read And Learn More: Pharmacology Question and Answers

Levodopa Uses:

  • Effective in idiopathic parkinsonism.

Levodopa Adverse effects:

  • GIT symptoms – nausea, vomiting, anorexia.
  • CVS affects – postural hypotension, tachycardia, palpitation, cardiac arrhythmia, and angina.
  • Alteration in taste sensation.
  • Abnormal movements – Dyskinesia, facial tics, grimacing, tongue thrusting.
  • Behavioral effects – mild anxiety, nightmares, mania, hallucinations.
  • Fluctuations in motor performance.

Anti Parkinsonian Drugs Short Essays

Question 1. Explain why levodopa is given along with carbidopa.


Decarboxylase inhibitor i.e., carbidopa prevents the conversion of levodopa to dopamine outside the brain by inhibiting the DOPA decarboxylase enzyme, peripherally.

  • This combination can cross the blood-brain barrier and reaches its site of action in the brain.
  • Other benefits obtained by this combination are:
    • It reduces the dose of levodopa Upton approx 1/4th
    • The plasma half-life of levodopa is prolonged.
    • The systemic concentration of dopamine is reduced.
    • Response to levodopa appears earlier.
    • Side effects like nausea and vomiting are reduced.
    • Cardiac complications are minimized.
    • Pyridoxine does not interfere with the treatment
    • The on-Off effect is minimized.
    • The degree of improvement may be higher.

Anti Parkinsonian Drugs Short Answers

Question 1. Is pyridoxine given with levodopa?


Pyridoxine is not given with levodopa because.

  • Pyridoxine enhances the decarboxylation of levodopa.
  • Reduces the drug availability to the CNS.
  • This results in the need for greater doses of levodopa for the same desired result
  • Thus, pyridoxine is not combined with levodopa.


Anti Arrythmic Drugs Important Notes

1. Antiarrythmic Drugs Classification

Anti-Arrythmic Drugs Classification

Anti Arrythmic Drugs Short Question And Answers

Question 1. Classification of anti-arrhythmic drugs.


Arrhythmic Drugs Classification:

1. Class – 1 – Sodium channel blockers.

  • Prolong repolarization – Quinidine, procainamide,
  • Shorten repolarization – Lignocaine, mexiletine.
  • Little or no repolarization – Propafenone, Flecainide.

2. Class 2 – β blockers.

  • Propranolal, esmolol.

3. Class – 3 – Potassium channel blockers.

  • Amiodarone, Dofetilide.

4. Class – 4 – Calcium channel blockers.

  • Verapamil, diltiazem.

Question 2. Why procainamide is preferred to procaine?


Procainamide is a derivative of procaine.

  • It is preferred to procaine because.
  1. It has weak anticholinergic action.
  2. Has antiarrhythmic action, while procaine has only a local anesthetic effect
  3. It is better tolerable.

Leave a Comment