Carbidopa/levodopa (also called co-careldopa) is a commonly prescribed medication used to treat Parkinson’s disease. It helps boost levels of dopamine in the brain, which helps improve movement symptoms like tremors, slowness, and rigidity.
Though carbidopa/levodopa is effective, taking too high of a dosage can cause side effects. Being aware of the potential side effects can help you work with your doctor to find the ideal dosage.
Common Side Effects
Some of the more common side effects of too much carbidopa/levodopa include:
- Nausea or vomiting
- Lightheadedness or dizziness
- Confusion
- Restlessness or agitation
- Trouble sleeping
- Vivid dreams or nightmares
- Mood changes like anxiety or depression
These side effects are usually temporary and can be managed by lowering the dosage. But it’s important to let your doctor know if any side effects are severe or don’t go away.
Dyskinesia
One potential side effect of too much levodopa is dyskinesia – involuntary, jerky movements. It most often affects the face, arms, and legs.
Dyskinesia may be a sign you need a lower dose. But sometimes dyskinesia happens even with lower doses after taking levodopa for many years. Doctors may add other medications to help manage dyskinesia.
Hallucinations and Delusions
Hallucinations (seeing or hearing things that aren’t there) and delusions (false beliefs) are possible side effects of too high a carbidopa/levodopa dose. They’re more common in elderly patients.
If you notice hallucinations or delusions, alert your doctor right away. Lowering the dosage often helps reverse these psychiatric side effects. Sometimes other medications are added to control them.
Orthostatic Hypotension
Orthostatic (or postural) hypotension is a sudden drop in blood pressure when standing up. It can cause dizziness, lightheadedness, and fainting.
Too much carbidopa/levodopa exacerbates orthostatic hypotension. Sitting or standing up slowly can help prevent blood pressure drops. Staying hydrated and wearing compression stockings also help.
Impulse Control Issues
Some people taking higher doses of levodopa develop impulse control problems like:
- Compulsive gambling
- Uncontrolled shopping
- Binge eating
- Hypersexuality
Alert your doctor if you experience any uncontrollable urges while on carbidopa/levodopa. Lowering the dosage often helps lessen these impulses.
Nutritional Deficiencies
High doses of carbidopa/levodopa can interfere with absorption of certain vitamins and minerals like vitamin B12, folic acid, and iron.
Work with your doctor to get bloodwork periodically to check for nutritional deficiencies. Supplements or dietary changes may be recommended to maintain healthy levels.
Wearing Off
“Wearing off” is when the effects of carbidopa/levodopa don’t last as long. As Parkinson’s progresses, wearing off becomes more common.
If you notice movement symptoms returning before your next scheduled dose, let your doctor know. Adjusting the timing or dosage of medication can help manage wearing off.
Building Tolerance
Over time, the body can become tolerant to carbidopa/levodopa’s effects. Higher and more frequent doses may be needed to control symptoms.
Work closely with your neurologist to find the most effective dosage over time. Non-medication therapies like exercise can also help manage symptoms.
Finding the Right Dosage
The goal is to take the lowest effective carbidopa/levodopa dosage that provides symptom relief with tolerable side effects.
Keep your doctor informed of any side effects you experience. Be patient – it can take some trial and error to find the sweet spot dose.
Good communication with your healthcare team is key to balancing effectiveness and side effects. Don’t hesitate to speak up!