Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
Quick facts
- Drug class
- Aromatic Amino Acid [EPC]
- How it is given
- respiratory (inhalation)
- Type
- human prescription drug
- Brand names
- Inbrija
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
is indicated for the intermittent treatment of OFF episodes in patients with Parkinson's disease treated with carbidopa/levodopa. INBRIJA is an aromatic amino acid indicated for the intermittent treatment of OFF episodes in patients with Parkinson's disease treated with carbidopa/levodopa ( 1 )
About this medicine
consists of a dry powder formulation of levodopa for oral inhalation with the INBRIJA inhaler. The inhalation powder is packaged in white hypromellose capsules. Each capsule contains a spray-dried powder of 42 mg levodopa active ingredient with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and sodium chloride. The active component of INBRIJA is levodopa, an aromatic amino acid. Its chemical name is (2S)-2-amino-3-(3,4-dihydroxyphenyl) propanoic acid and its structural formula is: Levodopa has a molecular weight of 197.19 g/mol and molecular formula C 9 H 11 NO 4 . Levodopa is a white to slightly off-white powder and is readily soluble in formic acid, slightly soluble in water, and practically insoluble in ethanol and diethyl ether; it dissolves in dilute hydrochloric acid. The INBRIJA inhaler is a plastic device with a blue body, blue cap, and white mouthpiece used for inhaling INBRIJA powder. The INBRIJA inhaler is breath-actuated by the patient. Under standardized in vitro testing conditions, the INBRIJA inhaler delivered 36.1 mg of levodopa (emitted dose) for the 42 mg capsule from the mouthpiece. No significant difference in emitted dose was observed when varying the flow rate and volume from 20 liters per minute/1L up to 90 liters per minute/2L. Peak inspiratory flow rates (PIFR) achievable through the INBRIJA inhaler were evaluated in 24 adult patients with mild to moderate Parkinson's disease. The mean PIFR was 64 L/min (range 39–98 L/min) for patients in the ON state and 57 L/min (range 29–98 L/min) in the OFF state. Chemical Structure
How it works
12.1 Mechanism of Action Levodopa, the metabolic precursor of dopamine, crosses the blood-brain barrier and presumably is converted to dopamine in the brain. This is thought to be the mechanism whereby levodopa relieves symptoms of Parkinson's disease.
Who should not take it
is contraindicated in patients currently taking a nonselective monoamine oxidase (MAO) inhibitor (e.g., phenelzine and tranylcypromine) or who have recently (within 2 weeks) taken a nonselective MAO inhibitor. Hypertension can occur if these drugs are used concurrently [see Drug Interactions (7.1) ]. INBRIJA is contraindicated in patients currently taking a nonselective monoamine oxidase (MAO) inhibitor or who have recently (within 2 weeks) taken a nonselective MAO inhibitor ( 4 , 7.1 )
Warnings and cautions
May cause falling asleep during activities of daily living ( 5.1 ) Avoid sudden discontinuation or rapid dose reduction to reduce the risk of withdrawal-emergent hyperpyrexia and confusion ( 5.2 ) Hallucinations/exacerbation of psychosis may occur. Patients with a major psychotic disorder should not be treated with INBRIJA ( 5.3 , 7.2 ) Impulse Control Disorders: consider dose reduction or stopping INBRIJA ( 5.4 ) May cause or exacerbate dyskinesia: adjustment of levodopa therapy may be considered, including stopping INBRIJA ( 5.5 ) Not recommended in patients with asthma, COPD, or other chronic underlying lung disease ( 5.6 ) 5.1 Falling Asleep During Activities of Daily Living and Somnolence Patients treated with levodopa, the active ingredient in INBRIJA, have reported falling asleep while engaged in activities of daily living, including the operation of motor vehicles, which sometimes resulted in accidents. Although many of these patients reported somnolence, some reported no warning signs (sleep attack) and believed that they were alert immediately prior to the event. Some of these events have been reported more than 1 year after the initiation of treatment. Prescribers should reassess patients for drowsiness or sleepiness. Prescribers should also be aware that patients may not acknowledge drowsiness or sleepiness until directly questioned about drowsiness or sleepiness during specific activities. Before initiating treatment with INBRIJA, advise patients about the potential to develop drowsiness and ask about factors that may increase the risk for somnolence with INBRIJA such as the concomitant use of sedating medications and the presence of sleep disorders. Consider discontinuing INBRIJA in patients who report significant daytime sleepiness or episodes of falling asleep during activities that require active participation (e.g., conversations, eating, etc.). If treatment with INBRIJA continues, patients should be advised not to drive and to avoid other activities that might result in harm if the patients become somnolent. […]
Reported side effects
The following serious adverse reactions are discussed below and elsewhere in the labeling: Falling Asleep During Activities of Daily Living and Somnolence [see Warnings and Precautions (5.1) ] Withdrawal-Emergent Hyperpyrexia and Confusion [see Warnings and Precautions (5.2) ] Hallucinations/Psychosis [see Warnings and Precautions (5.3) ] Impulse Control/Compulsive Behaviors [see Warnings and Precautions (5.4) ] Dyskinesia [see Warnings and Precautions (5.5) ] Bronchospasm in Patients with Lung Disease [see Warnings and Precautions (5.6) ] Glaucoma [see Warnings and Precautions (5.7) ] The most common adverse reactions (incidence ≥ 5% and higher than placebo) were cough, nausea, upper respiratory tract infection, and sputum discolored ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merz Pharmaceuticals, LLC at 1-800-367-5109 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Adverse Reactions in Study 1 Table 1 lists the adverse reactions that occurred in at least 2% of patients with Parkinson's disease who were treated with INBRIJA 84 mg and higher than placebo for OFF periods in Study 1 [see Clinical Studies (14) ]. Study 1 was a double-blind, placebo-controlled study, in which 114 patients received INBRIJA 84 mg (two 42 mg capsules) for an average of 2 doses per day, to a maximum of 5 times a day, and 112 patients received placebo. INBRIJA-treated patients were 45-82 years of age (mean 63.5 years of age) and were predominantly male (72%) and white (94%). All patients were also treated with oral carbidopa/levodopa. The most common adverse reactions (≥ 5% and higher than placebo) in Study 1 were cough, nausea, upper respiratory tract infection, and sputum discolored. […]
Interactions with other medicines
Monitor patients on MAO-B inhibitors for orthostatic hypotension ( 7.1 ) Dopamine D2 antagonists, isoniazid, and iron salts: May reduce the effectiveness of INBRIJA ( 7.2 , 7.3 ) 7.1 Monoamine Oxidase (MAO) Inhibitors The use of nonselective MAO inhibitors with INBRIJA is contraindicated [see Contraindications (4) ] . Discontinue use of any nonselective MAO inhibitors at least two weeks prior to initiating INBRIJA. The use of selective MAO-B inhibitors with INBRIJA may be associated with orthostatic hypotension. Monitor patients who are taking these drugs concurrently. 7.2 Dopamine D2 Receptor Antagonists and Isoniazid Dopamine D2 receptor antagonists (e.g., phenothiazines, butyrophenones, risperidone, metoclopramide) and isoniazid may reduce the effectiveness of levodopa. Monitor patients for worsening Parkinson's symptoms. 7.3 Iron Salts Iron salts or multivitamins containing iron salts can form chelates with levodopa and consequently reduce the bioavailability of levodopa.
Use in specific groups
Pregnancy: Based on animal data, may cause fetal harm ( 8.1 ) 8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of INBRIJA in pregnant women. In animal studies, carbidopa/levodopa has been shown to be developmentally toxic (including teratogenic effects) [see Data ]. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. Data Animal Data When administered to pregnant rabbits throughout organogenesis, carbidopa/levodopa caused both visceral and skeletal malformations in rabbits. No teratogenic effects were observed when carbidopa/levodopa was administered to pregnant mice throughout organogenesis. There was a decrease in the number of live pups delivered by rats receiving carbidopa/levodopa during organogenesis. 8.2 Lactation Risk Summary The prolactin-lowering action of dopamine suggests that levodopa may interfere with lactation, although there are limited data on the effects of levodopa on milk production in lactating women. Levodopa has been detected in human milk. There are no adequate data on the effects of levodopa on the breastfed infant. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for INBRIJA and any potential adverse effects on the breastfed infant from INBRIJA or from the underlying maternal condition. 8.4 Pediatric Use Safety and effectiveness in pediatric patients have not been established. 8.5 Geriatric Use Of the Parkinson's disease patients in Study 1 who took INBRIJA 84 mg, 49% (n=56) were 65 years of age and older and 51% (n=58) were under 65 years of age. Of these patients, the following age-related differences in adverse reactions were reported in patients 65 years of age and older vs. in patients under 65 years of age, respectively: cough 25% vs. 5%; upper respiratory tract infection 11% vs. 2%; nausea 7% vs. 3%; vomiting 4% vs. 2%; pain in the extremities 4% vs. 0%; and discolored nasal discharge 4% vs. 0%.
If too much is taken
Based on the limited available information, the acute symptoms of carbidopa/levodopa overdosage can be expected to arise from dopaminergic overstimulation. Using more than one dose (84 mg) to treat the same OFF period may result in CNS disturbances, with an increasing risk for cardiovascular disturbance (e.g., hypotension, tachycardia) and increased risk for new or worsening psychiatric problems at higher doses. Reports of rhabdomyolysis and transient renal insufficiency suggest that levodopa overdosage may give rise to systemic complications. Monitor patients and provide supportive care. Patients should receive electrocardiographic monitoring for the development of arrhythmias; if needed, appropriate antiarrhythmic therapy should be given. The possibility that the patient may have taken other drugs, increasing the risk of drug interactions (especially catechol-structured drugs) should be taken into consideration.
Storing it safely
16.2 Storage and Handling Store in a dry place between 20°C to 25°C (68°F to 77°F), excursions permitted to 15°C to 30°C (59°F to 86°F). INBRIJA capsules should always be stored in the blister packaging and only removed immediately before use. INBRIJA capsules should not be stored inside the INBRIJA inhaler. INBRIJA capsules should be used only with the INBRIJA inhaler. The INBRIJA inhaler should not be used to administer any other medicines.
Before you take anything new
Tell your pharmacist or doctor about every medicine you take — including ones bought without a prescription, herbal products and supplements. Interactions are one of the most common avoidable causes of harm from medicines, and a pharmacist can check your full list in a couple of minutes.
This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 20 July 2026. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.