Section 03 · Monograph
Levodopa inhalation powder
Reviewed Nov 2026FDA label
InbrijaDopamine precursor · inhaled
- Forms
- Inhaler: 42mg cartridge
- Dose
- up to 5x/day PRN OFF episodes
- MOA
- Rapid pulmonary levodopa absorption
Indications
- Intermittent treatment of OFF episodes in patients with Parkinson's disease already treated with a carbidopa-levodopa regimenFDA-labeled
Mechanism of Action
- Levodopa is the metabolic precursor of dopamine; it crosses the blood-brain barrier and is converted to dopamine in the brain, transiently relieving parkinsonian motor symptoms during an OFF episode
- Oral inhalation delivers levodopa directly via the pulmonary route, producing rapid systemic absorption intended to abort OFF episodes more quickly than oral tablets
- Inbrija is administered without a peripheral decarboxylase inhibitor co-formulated in the capsule; patients continue their background oral carbidopa-levodopa regimen for peripheral decarboxylase inhibition
Full Dosing
Adult / usual
- For oral inhalation only, using the INBRIJA inhaler device — capsules must never be swallowed
- Each capsule contains 42 mg levodopa; standard dose is the contents of two capsules (84 mg total) inhaled at the onset of an OFF episode
- May be repeated for OFF symptoms up to 5 times per day
- Maximum total daily dose: 420 mg (10 capsules)
- Used as an adjunct to, not a replacement for, the patient's scheduled oral carbidopa-levodopa regimen
Contraindications
- Concurrent use of a nonselective MAO inhibitor, or use within the preceding 2 weeks
Drug Interactions
- Nonselective MAO inhibitors: contraindicated
- Selective MAO-B inhibitors: increased risk of orthostatic hypotension; monitor blood pressure
- Dopamine D2-receptor antagonists and isoniazid: may reduce levodopa effectiveness
- Iron salts: may reduce levodopa bioavailability
Adverse Effects
- Cough (~15% vs 2% placebo) — most common adverse reaction
- Nausea (~5% vs 3% placebo)
- Upper respiratory tract infection
- Discolored sputum
- Dyskinesia may occur or worsen
- Hallucinations/psychosis
Monitoring Parameters
- Pulmonary function (e.g., spirometry/FEV1) in patients with underlying lung disease before and during treatment; not recommended in asthma, COPD, or other chronic lung disease due to bronchospasm risk
- Assess for cough and respiratory symptoms with each use
- Screen for daytime somnolence/sudden sleep onset before driving or operating machinery
- Assess for hallucinations, psychosis, and impulse control/compulsive behaviors
- Intraocular pressure in patients with glaucoma
- Monitor for dyskinesia
Pregnancy & Lactation
- No adequate human pregnancy data; animal data suggest potential for fetal harm (consistent with other levodopa-containing products)
- Levodopa is detected in human milk; insufficient data on effects on the breastfed infant or on milk production