Carbidopa/levodopa

Question 1

Indications for use

Answer 1

Parkinson’s disease

Question 2

MOA

Answer 2

Precursor of dopamine, cross the BBB, converting dopamine in the brain

Carbidopa can decrease peripheral side effects and lower effectiveness dose of levodopa allowing it to enter CNS (cross BBB)

Question 3

Pharmacological effects

Answer 3

Anti parkinsonism effect

Question 4

Pharmacokinetics (way of administration, metabolism, elimination, T1/2)

Answer 4

ADM: oral
Metabolism: peripherally, allows it to be taken by the CNS (intracellular, enzyme aminoacid decarboxylase)
Elimination: urine
T1/2: 90min

Question 5

Overdose effects

Answer 5

Dyskinesia (involuntary muscle spams), hallucinations, compulsive disorders

Question 6

Side effects

Answer 6

Nausea, vomiting, tachycardia, uncontrolled movements (motor fluctuation), postural hypotension.

Question 7

Contraindications for use

Answer 7

hypersensitivity, glaucoma, CVS and endocrine diseases.
PT receiving MAO inhibitors,

Question 8

Drug interactions

Answer 8

Quetiapine: reduce effectiveness
VitB6 (pyridoxine): reverse effect of levodopa & reduce effectiveness

Question 9

Interactions with products (meal), drinks

Answer 9

Adm 60min before the meal

Question 10

Children

Answer 10

Not used

Question 11

Elderly patients

Answer 11

Systemic exposure is increased.

Question 12

Pregnant women

Answer 12

Category C

Question 13

Overdose treatment

Answer 13

Gastric lavage, intake of activated carbon, and, if necessary, symptomatic treatment in a hospital setting.

There is no specific antidote. Pyridoxine does not reverse the effect of the drug.

There are currently no data on the use of dialysis. It is necessary to monitor heart activity to prevent the development of arrhythmias.