levodopa

Absorption: 70% absorbed following oral inhalation.

Distribution: Extensively distributed to tissues.

Metabolism/Excretion: Primarily metabolized in liver by decarboxylation (via dopa decarboxylase) and O-methylation (by catechol-O-methyltransferase [COMT]).

Half-Life: 2.3 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
Inhaln	unknown	30 min	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Concurrent or recent (within past 2 wk) use of nonselective MAO inhibitor therapy;
Major psychotic disorders;
Asthma, COPD, or underlying lung disease (may ↑ risk of bronchospasm).

Use Cautiously in:

Glaucoma (may ↑ intraocular pressure);
OB: Safety not established;
Lactation: Use while breast feeding only if potential maternal benefit justifies potential risk to infant;
Pedi: Safety and effectiveness not established;
Geri: risk of adverse reactions.

Adv. Reactions/Side Effects ⬆ ⬇

CV: orthostatic hypotension

EENT: ↑intraocular pressure, nasal discharge discoloration, nasopharyngitis

GI: ↑liver enzymes, hyperbilirubinemia, nausea, vomiting

MS: dyskinesias

Neuro: aggression, agitation, confusion, delirium, delusions, disorientation, hallucinations, headache, insomnia, paranoid ideation, psychosis, sedation, urges (gambling, sexual), vivid dreams

Resp: cough, sputum discoloration, upper respiratory tract infection

Misc: falls

Interactions ⬆ ⬇

Drug-drug:

Nonselective MAO inhibitors, including phenelzine or tranylcypromine, can ↑ risk of severe hypertension; concurrent use contraindicated (MAO inhibitor must be discontinued ≥2 wk before initiating levodopa).
Selective MAO inhibitors, including rasagiline or selegiline may ↑ risk of orthostatic hypotension.
Haloperidol, isoniazidmetoclopramide, phenothiazines, or risperidone may ↓ effectiveness.
Iron or multivitamins containing iron may ↓ absorption of levodopa.

Route/Dosage ⬆ ⬇

Should be used in patients already taking carbidopa/levodopa.
Inhaln
(Adults ): 84 mg as needed for "off" episodes up to 5 times per day (max = 420 mg/day).

Availability ⬆ ⬇

Capsules for oral inhalation: 42 mg

Assessment ⬆ ⬇

Assess parkinsonian symptoms (akinesia, rigidity, tremors, pill rolling, shuffling gait, mask-like face, twisting motions, and drooling) during therapy. "On-off phenomenon" may cause symptoms to appear or improve suddenly.
Assess for signs and symptoms of dyskinesia (abnormal movements, uncontrolled sudden movements of face, tongue, or other body parts) before and during therapy. May increase during therapy requiring dose adjustment or discontinuation.
Monitor for signs and symptoms of behavior changes (hallucinations, psychotic behavior, paranoid ideation, delusions, confusion, mania, disorientation, aggressive behavior, agitation, delirium) during therapy. Consider reducing dose or discontinuing therapy.

Lab Test Considerations:

May cause ↑ alkaline phosphatase, AST, ALT, lactic dehydrogenase (LDH), and bilirubin.
- May cause ↑ blood urea nitrogen (BUN), hemolytic anemia and positive direct antibody test.

Implementation ⬆ ⬇

Inhaln: Administer up to 5 times daily when symptoms of an OFF period start to return. Capsules are for oral inhalation only; use only with the Inbrija inhaler.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication when their Parkinson’s symptoms (OFF periods) first occurs as directed. Instruct patient in correct use of Imbrija inhaler and that each dose is 2 capsules. Capsules are for use in inhaler; do not take orally. Discontinue slowly; abrupt discontinuation may cause fever, confusion, stiff muscles, changes in breathing and heartbeat. Advise patient to read Patient Information before starting therapy and with each Rx refill in case of changes.
May cause sudden onset of sleep, drowsiness, or dizziness. Advise patient to avoid driving and other activities that require alertness until response to drug is known.
Inform patient that medication may cause dark color bodily fluids (saliva, sputum, urine, sweat).
Advise patient to notify health care professional if abnormal involuntary movements appear or get worse during therapy.
Caution patient to change positions slowly to minimize orthostatic hypotension. Health care professional should be notified if orthostatic hypotension occurs.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
Advise patient and family to notify health care professional if signs and symptoms of hallucinations or psychosis (being overly suspicious or feeling people want to harm you, disorientation, believing things that are not real, aggressive behavior, seeing or hearing things that are not real, agitation, confusion, delirium, increase activity or talking), or if new or increased gambling, sexual, or other intense urges occur. Dose reduction may be required.
Advise females of reproductive potential to use effective contraception and avoid breast feeding during therapy. Advise patient to notify health care professional if pregnancy is planned or suspected, or if breast feeding.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇