Carbidopa and Levodopa

Carbidopa

Carbidopa-levodopa combination therapy aims to raise dopamine levels in the brain, which are low in Parkinson's disease patients. Dopamine levels in the brain are raised by levodopa, which the brain transforms into dopamine. People with idiopathic Parkinson disease experience less tremor, stiffness, and slow mobility thanks to levodopa. Levodopa is not degraded in the body before it reaches the brain thanks to carbabidopa.

Mechanism of Action

• When taken alone, levodopa undergoes a rapid peripheral conversion to dopamine, which lessens the intended therapeutic impact.
• Levodopa is peripherally converted to dopamine by the enzyme amino acid decarboxylase (dopa decarboxylase), which is inhibited by carbidopa.

Indication

• Parkinson disease, postencephalitic parkinsonism, and symptomatic parkinsonism.

Dose

• Expressed as levodopa, the usual maintenance dose is 0.75-1.5gm per day in divided doses, initially 100-125mg tid/qid adjusted according to response.

Contraindication

• Carbidopa or levodopa hypersensitivity, narrow-angle glaucoma, and a history of possible melanoma.

Side Effect

• Involuntary movements, ataxia, muscle twitching, an increase in hand tremor, fatigue, confusion, insomnia, nightmares, mental disturbances, anxiety, depression with suicidal tendencies, delirium, skin rash, hoarseness, irregular breathing patterns, neuroleptic malignant syndrome, orthostatic hypotension, irregular heartbeat, palpitations, arrhythmias, phlebitis, anorexia, dry mouth, vomiting, excess salivation,

Nursing Consideration

• Make sure that the Sinemet CR sustained-release form of the medication is not chewed or crushed.
• Consistently give when it comes to food. Meals high in protein may prevent levodopa from being absorbed.
• Levodopa-carbidopa therapy is often started with a morning dosage when the patient has been taking levodopa alone for at least 8 hours.
• Make precise observations and notify others right once of any negative responses and treatment effects. The patient's tolerance and reaction to levodopa dictate the rate of dosage increase in the main.
• Keep an eye on your vital signs, especially when you're adjusting your dosage. Report any changes to your blood pressure, pulse, and breathing rhythm.
• Check all patients carefully for any changes in behavior. Suicidal inclinations in depressed patients should be continuously monitored.
• It is important to regularly check your blood sugar levels.
• Routine checks for blood sugar, kidney, liver, and CBC with differential and Hb%.
• Report any abnormal involuntary movement as soon as possible, including face grimacing, excessive chewing, tongue protrusion, repetitive mouth opening and closing, head bobbing, jerky arm and leg movements, and excessive respiration.
• Tracking the results of treatment A rise in bradykinesia is present in certain patients. The patient constantly trips and falls because they cannot begin to walk. In these patients, dosage reduction might be necessary.