<p>Intravenously administered levodopa is cleared at a rate of 14.2mL/min/kg in elderly patients and 23.4mL/min/kg in younger patients<sup class="text-reference-group"><a class="reference-popover-link" data-content="Robertson DR, Wood ND, Everest H, Monks K, Waller DG, Renwick AG, George CF: The effect of age on the pharmacokinetics of levodopa administered alone and in the presence of carbidopa. Br J Clin Pharmacol. 1989 Jul;28(1):61-9. (PubMed ID 2775615)" href="#reference-A177802">4</a></sup>. When given carbidopa, the clearance of levodopa was 5.8mL/min/kg in elderyly patients and 9.3mL/min/kg in younger patients<sup class="text-reference-group"><a class="reference-popover-link" data-content="Robertson DR, Wood ND, Everest H, Monks K, Waller DG, Renwick AG, George CF: The effect of age on the pharmacokinetics of levodopa administered alone and in the presence of carbidopa. Br J Clin Pharmacol. 1989 Jul;28(1):61-9. (PubMed ID 2775615)" href="#reference-A177802">4</a></sup>.</p>