Dopamine prodrug — crosses the BBB via LAT1 (dopamine does not). Decarboxylated by AADC to dopamine both centrally and peripherally. Carbidopa (peripheral AADC inhibitor) is co-administered to prevent peripheral dopamine formation (nausea, hypotension) and preserve more L-DOPA for CNS conversion.
Half-Life (t½)
PO: 1.5h
Dosing Guidelines
PO: Typical 400 mg (Range: 100–1000 mg)
Target Organ Systems
nervous
Interactions
Tyrosine (synergistic): Upstream AA precursor. Protein meals compete with L-DOPA for LAT1 → separate dosing from meals.
Dopamine (synergistic): Converts to dopamine in vivo.
Vitamin B6 (caution): Without carbidopa, B6 accelerates peripheral AADC conversion of L-DOPA → reduced CNS exposure. Clinically mitigated by fixed-dose carbidopa combinations. [Mars 1975]