Sinemet Side Effects

Generic name: carbidopa / levodopa

Medically reviewed by Philip Thornton, DipPharm. Last updated on Mar 17, 2024.

Note: This document provides detailed information about Sinemet Side Effects associated with carbidopa / levodopa. Some dosage forms listed on this page may not apply specifically to the brand name Sinemet.

Applies to carbidopa / levodopa: oral capsule extended release, oral tablet, oral tablet disintegrating, oral tablet extended release.

Serious side effects of Sinemet

Along with its needed effects, carbidopa / levodopa may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking carbidopa / levodopa:

More common

• twitching, twisting, uncontrolled repetitive movements of the tongue, lips, face, arms, or legs

Less common

• bladder pain
• bloody or cloudy urine
• chest pain
• confusion
• difficult, burning, or painful urination
• discouragement
• feeling sad or empty
• frequent urge to urinate
• inability to move the eyes
• increased blinking or spasms of the eyelid
• irritability
• lack of appetite
• loss of interest or pleasure
• lower back or side pain
• seeing, hearing, or feeling things that are not there
• sticking out of tongue
• tiredness
• trouble concentrating
• trouble in breathing, speaking, or swallowing
• trouble sleeping
• uncontrolled twisting movements of the neck, trunk, arms, or legs
• unusual facial expressions

Incidence not known

• anxiety
• black, tarry stools
• bluish color
• blurred vision
• changes in skin color
• chest discomfort
• chills
• convulsions
• cough or hoarseness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry mouth
• false beliefs that cannot be changed by facts
• fast, irregular, pounding, or racing heartbeat or pulse
• feelings about hurting oneself or others
• fever with or without chills
• general feeling of tiredness or weakness
• high fever
• hyperventilation
• increased in sexual ability, desire, drive, or performance
• increased interest in sexual intercourse
• increased sweating
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• loss of bladder control
• lower back or side pain
• nausea
• pain
• pain or discomfort in the arms, jaw, back, or neck
• restlessness
• seeing, hearing, or feeling things that are not there
• severe muscle stiffness
• shaking
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• swelling of the foot or leg
• swollen glands
• tenderness
• tiredness
• unusual bleeding or bruising
• unusual tiredness or weakness
• unusually pale skin
• vomiting

Other side effects of Sinemet

Some side effects of carbidopa / levodopa may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• acid or sour stomach
• back or shoulder pain
• belching
• body aches or pain
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• diarrhea
• difficulty having a bowel movement (stool)
• ear congestion
• headache
• heartburn
• indigestion
• loss of voice
• muscle cramps
• nasal congestion
• runny nose
• sneezing
• stomach discomfort, upset, or pain
• unusual dreams
• weight loss

Incidence not known

• abdominal or stomach distress
• bad, unusual, or unpleasant (after) taste
• belching
• change in taste
• dark sweat
• double vision
• enlarged pupils
• feeling of warmth
• hair loss or thinning of the hair
• lack or loss of strength
• redness of the face, neck, arms, and occasionally, upper chest
• seeing double
• skin rash, hives or welts, itching

For healthcare professionals

Applies to carbidopa / levodopa: enteral suspension, oral capsule extended release, oral tablet, oral tablet disintegrating, oral tablet extended release.

General

The most common adverse reactions reported include nausea, dizziness, headache, insomnia, abnormal dreams, dry mouth, dyskinesia, anxiety, constipation, vomiting, and orthostatic hypotension.^[Ref]

Nervous system

• Very common (10% or more): Headache (up to 17%), dyskinesia (up to 16.5%), dizziness (up to 12%)
• Common (1% to 10%): Confusion, dystonia, on-off phenomena, hypoesthesia, polyneuropathy, tremor, dysgeusia, bradykinesia
• Uncommon (0.1% to 1%): Paresthesia, ataxia, gait disturbance, convulsion
• Rare (less than 0.1%): Malignant, neuroleptic syndrome
• Frequency not reported: Chorea, somnolence, memory impairment, sense of stimulation
• Postmarketing reports: Polyneuropathy^[Ref]

Psychiatric

• Very common (10% or more): Anxiety, insomnia, depression (up to 11%)
• Common (1% to 10%): Hallucinations, psychosis, abnormal dreams, sleep disorder, agitation, impulsive behavior, sleep attacks
• Uncommon (0.1% to 1%): Suicide, dementia, disorientation, euphoric mood, fear
• Rare (less than 0.1%): Abnormal thinking

Postmarketing: Suicide attempt, suicidal ideation^[Ref]

Gastrointestinal

• Very common (10% or more): Nausea (up to 30%), constipation (up to 22%)
• Common (1% to 10%): Dry mouth, constipation, vomiting, hiatal hernia, postoperative ileus, diarrhea, dyspepsia, abdominal distension, dysphagia, flatulence, bitter taste
• Uncommon (0.1% to 1%): Salivary hypersecretion
• Rare (less than 0.1%): Bruxism, saliva discoloration, glossodynia, hiccups, trismus, burning tongue sensation
• Frequency not reported: Heartburn^[Ref]

Cardiovascular

• Common (1% to 10%): Ischemic events, orthostatic hypotension, peripheral edema, hypertension, syncope, irregular heart rate, hypotension
• Uncommon (0.1% to 1%): Palpitations, phlebitis
• Frequency not reported: Chest pain, myocardial infarction^[Ref]

Cardiovascular ischemic events occurred in 2.4% (7 of 289) patients receiving carbidopa-levodopa extended-release capsules compared to 1.1% (1 of 92) of patients receiving placebo in early Parkinson's disease clinical trials. In advanced Parkinson's disease, 0.7 % (3 of 450) patients experienced cardiovascular ischemic events. These patients had a previous history of ischemic heart disease or risk factors for ischemic heart disease.^[Ref]

Dermatologic

• Common (1% to 10%): Excessive granulation tissue, rash, contact dermatitis, hyperhidrosis, pruritus
• Uncommon (0.1% to 1%): Alopecia, erythema, urticaria
• Rare (less than 0.1%): Sweat discoloration, angioedema
• Postmarketing reports: Henoch-Schonlein purpura^[Ref]

Local

• Very common (10% or more): Insertion site complication, incision site erythema (19%), post-operative wound infection
• Common (1% to 10%): Incision site cellulitis, post procedural infection, device dislocation, device occlusion
• Uncommon (0.1% to 1%): Postoperative abscess, bezoar, ischemic colitis
• Postmarketing reports: Gastric perforation, gastrointestinal perforation, small intestinal ischemia, small intestinal perforation^[Ref]

Insertion site complication was reported in 57% of patients who received this drug compared with 44% of patients who received a PEG-J tube without receiving treatment. The most common adverse reactions associated with naso-jejunal (NJ) insertion were oropharyngeal pain, abdominal distention, abdominal pain, abdominal discomfort, pain, throat irritation, gastrointestinal injury, esophageal hemorrhage, anxiety, dysphagia, and vomiting. The most common adverse reactions associated with PEG-J insertion included upper abdominal pain, duodenal ulcer, duodenal ulcer hemorrhage, erosive duodenitis, erosive gastritis, gastrointestinal hemorrhage, intussusception, peritonitis, post-operative abscess, and small intestine ulcer.^[Ref]

Hypersensitivity

• Postmarketing reports: Anaphylactic reaction, bullous lesions^[Ref]

Respiratory

• Common (1% to 10%): Upper respiratory tract infection, atelectasis, dyspnea, aspiration pneumonia, oropharyngeal pain
• Uncommon (0.1% to 1%): Dysphonia, hoarseness
• Rare (less than 0.1%): Abnormal respiration
• Frequency not reported: Bizarre breathing pattern^[Ref]

Hepatic

• Frequency not reported: Elevated alkaline phosphatases, AST, ALT, LDH, and bilirubin^[Ref]

Renal

• Frequency not reported: Elevated serum urea and creatinine^[Ref]

Other

• Very common (10% or more): Asthenia, fatigue
• Common (1% to 10%): Pyrexia, malaise
• Frequency not reported: Hot flashes^[Ref]

Genitourinary

• Common (1% to 10%): Urinary tract infection, urinary incontinence, urinary retention
• Uncommon (0.1% to 1%): Urinary frequency
• Rare (less than 0.1%): Priapism^[Ref]

Hematologic

• Common (1% to 10%): Anemia
• Uncommon (0.1% to 1%): Leukopenia, thrombocytopenia
• Rare (less than 0.1%): Hemolytic anemia
• Very rare (less than 0.01%): Agranulocytosis
• Frequency not reported: Positive Coombs test, reduced hemoglobin and hematocrit^[Ref]

Metabolic

• Very common (10% or more): Decreased weight
• Common (1% to 10%): Anorexia, increased weight, vitamin B6 deficiency, vitamin B12 deficiency
• Frequency not reported: Elevated blood sugar
• Postmarketing reports: Folic acid deficiency^[Ref]

Musculoskeletal

• Common (1% to 10%): Back pain, shoulder pain
• Uncommon (0.1% to 1%): Muscle cramps, neck pain
• Frequency not reported: Muscle twitching, leg pain^[Ref]

Ocular

• Uncommon (0.1% to 1%): Blepharospasm, diplopia, optic ischemic neuropathy, blurred vision
• Rare (less than 0.1%): Mydriasis, oculogyric crisis, activation of a latent Horner's syndrome^[Ref]

Oncologic

• Rare (less than 0.1%): Malignant melanoma^[Ref]

Frequently asked questions

• Is Rytary better than Sinemet?
• What is the half life for sinemet? How long should side effects continue?
• How long does it take carbidopa levodopa to work?
• How often should carbidopa/levodopa be taken?
• Can carbidopa/levodopa cause high blood pressure?
• What foods should be avoided when taking levodopa?
• What is the difference between carbidopa, levodopa, and Rytary?
• How long does it take for Rytary to start working?

Further information

Sinemet side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer