Common Parkinson’s Medications

Carbidopa-Levodopa & PD Medications 

Overview: There are several types of medications used to treat Parkinson’s (PD). The majority utilize a combination of carbidopa and levodopa, although you may be prescribed a range of supporting medications to address specific symptoms or side effects of Parkinson’s. Below, you will learn about carbidopa-levodopa and its various forms and side effects. 

Carbidopa-Levodopa – is the classic pharmaceutical combination to treat Parkinson’s. Levodopa converts into dopamine – the neurotransmitter that helps control movement, mood, and memory – in the brain. Carbidopa supports the levodopa by preventing the body from breaking levodopa down before it crosses the blood-brain barrier. It reduces some of the side effects associated with levodopa. Carbidopa-levodopa is typically prescribed via immediate or extended-release tablets and capsules. It can also be taken via intestinal gel pumped to the small intestine (like the Duopa pump) or inhaled via dry powder aerosol (like Inbrija). 

Side effects can include nausea, vomiting, loss of appetite, lightheadedness, lowered blood pressure, confusion, dyskinesia, hallucinations, sleepiness, or impulsivity. Side effects may worsen over time and should be tracked and discussed with your doctor. 

What you eat when you take carbidopa-levodopa may impact how well your body receives it. To manage side effects like nausea, consider taking ginger tea along with your dose or consuming a simple snack like graham crackers or soup crackers to settle your stomach. If you experience more severe nausea and an upset stomach, you may need to take your dose with a heartier snack or meal. Some individuals experience less benefit if they take the medication alongside a high protein meal. If so, it is recommended to avoid proteins for 30 minutes before and 60 minutes after the meal. Iron supplements may also reduce absorption. 

It is important to always discuss changes in medication with your doctor and to understand how all the medications you take interfere with each other. Make sure your pharmacist knows of all medications and supplements you take, including over-the-counter medications and vitamins/supplements.

Common Levodopa Medications 

Sinemet – immediate release tablets to treat slowness, stiffness, tremor. Dosage: 10-100mg, 25-100mg, 25-250mg 

Treatment: 150 - 1,000mg per day, divided into 3-4 doses 

Side Effects: nausea, low blood pressure, confusion, hallucinations, dyskinesia Sinemet CR – controlled release tablets to treat slowness, stiffness, tremor. No longer in production, but generic forms are still available. 

Dosage: 25-100mg, 50-200mg 

Treatment: 400 - 1,600mg, divided in doses, depending on daily need 

Side Effects: nausea, low blood pressure, confusion, hallucinations, dyskinesia Duopa – this surgical pump delivers carbidopa-levodopa through an implanted tube in the small intestine in order to increase “on” times and reduce dyskinesia. 

Dosage: 4.86/20mL 

Treatment: Up to 2,000 mg of levodopa over 16 hours 

Side Effects: nausea, low blood pressure, confusion, hallucinations, dyskinesia Rytary – capsule with small beads of carbidopa-levodopa that dissolve and are absorbed at different rates to improve “on” times while requiring fewer doses. 

Dosage: 23.75-95 mg, 36.25-145 mg, 48.75-195 mg, 61.25-245 mg 

Treatment: 855 - 2,340 mg divided in doses depending on daily need 

Side effects: nausea, low blood pressure, confusion, hallucinations, dyskinesia Stalevo – tablet combining carbidopa-levodopa-entacapone to reduce “off” periods. Dosage: 12.5-50-200 mg, 18.75-75-200 mg, 25-100-200 mg, 31.25-125-200 mg, 37.5-150-200 mg, 50-200-200 mg 

Treatment: 150 - 1,600 mg divided into doses depending on daily need. Max 8 tablets per day 

Side effects: nausea, lower blood pressure, confusion, hallucinations, dyskinesia, diarrhea, discolored urine 

Inbrija – levodopa inhalation powder used for early morning or sudden off periods, giving a low but fast-acting dopamine boost. Considered a “rescue drug.” 

Dosage: 42mg, 84mg 

Treatment: 1 to 2 capsules up to 5 times per day 

Side Effects: cough, dyskinesia 

Vyalev – liquid form of carbidopa-levodopa, delivered continuously through under-the-skin pump device to reduce “off times.” 

Side Effects: Skin irritation and infection at site of skin infusion. Hallucinations. 

Other Parkinson’s Medications 

Dopamine Agonists – A dopamine agonist is a class of drugs that mimics dopamine by stimulating parts of the brain influenced by dopamine. They do not replace or convert into dopamine, as levodopa does. They are not as potent as carbidopa-levodopa, but may also cause less dyskinesia. They are used to treat the motor symptoms of Parkinson’s. Side effects include constipation, dizziness, headaches, indigestion, arrhythmia, nausea, and orthostatic hypotension. Long-term side effects may include confusion, mania, and hallucinations. They may also cause impulse control issues like gambling, hypersexuality, or excess shopping. Mirapex, Ropinirole, APOKYN, KYNMOBI, Rotigotine Transdermal (Neupro) 

MAO-B Inhibitors – Monamine Oxidase Type B inhibitors act to block an enzyme (monoamine oxidase B) that breaks down dopamine, essentially making more dopamine available to the brain. MAO-B inhibitors may be used as early medication therapy or in addition to other medications like levodopa. They are used to reduce motor fluctuations or off times. Side effects include nausea, dry mouth, lightheadedness, constipation, confusion, and hallucinations. 

Selegiline (Eldepryl), Zelapar, Rasagiline (Azilect), Safinamide (Xadago) 

Anticholinergics – Anticholinergic medications are the oldest class of medication to treat Parkinson’s. They block acetylcholine, a brain chemical that influences movement, in order to reduce tremor and dystonia associated with “off” periods. They can also be used for excess drooling and sweating. Side effects include blurred vision, dry mouth, constipation, and urinary retention. Some evidence suggests they may cause cognitive slowing, confusion, and hallucinations in older patients. 

Benztropine (Cogentin), Trihexyphenidyl HCL (Artane) 

Amantadine – An antiviral drug and dopamine promoter, Amantadine was originally developed to treat the flu. It is used to reduce dyskinesias associated with dopamine medications. Side effects include nausea, dizziness, insomnia, confusion, paranoia, low blood pressure, and leg discoloration. 

Symmetrel, Gocovri, Osmolex ER 

Adenosine Receptor Antagonist – The basal ganglia, a crucial brain circuit, has adenosine A2A receptors located right next to the dopamine receptors targeted by other PD medications. Research has indicated that blocking these receptors may improve Parkinson’s symptoms by suppressing movement to reduce “off” times. Side effects include dizziness, constipation, nausea, insomnia, dyskinesia, and hallucinations. 

Nourianz 

COMT Inhibitors – Catechol-O-methul transferase (COMT) is an enzyme in the body that deactivates levodopa before it enters the brain. COMT inhibitors prevent this action in order to extend “on” times for Parkinson’s patients. They are most often used in combination with other PD medications. Side effects include dyskinesia, confusion, hallucinations, discoloration of urine, and diarrhea. 

Entacapone (Comtan), Tolcapone (Tasmar), Stalevo, Opicapone (Ongentys)