Perioperative Management of Madopar for DSA Under General Anesthesia
Give the 4pm dose of Madopar now (at 2:50pm) before the patient goes for DSA, as levodopa should be continued up until the time of anesthesia when the patient can still take oral medications. 1
Rationale for Continuing Madopar
The FDA label explicitly states that levodopa/carbidopa (and by extension levodopa/benserazide formulations like Madopar) may be continued as long as the patient is permitted to take fluids and medication by mouth when general anesthesia is required 1
Abrupt discontinuation or significant dose reduction of levodopa carries serious risks, including the development of neuroleptic malignant syndrome (NMS)-like symptoms with hyperpyrexia and confusion 1
DSA (digital subtraction angiography) is typically a relatively short procedure, and the patient will likely be able to resume oral intake within hours postoperatively 1
Practical Implementation
Administer the Madopar dose immediately (at 2:50pm, approximately 1 hour early) rather than waiting until 4pm, since the patient will be taken to the procedure in 10 minutes 1
Giving the dose 1 hour early is preferable to missing it entirely, as maintaining therapeutic levodopa levels is critical to prevent acute parkinsonian deterioration 1
The standard Madopar formulation reaches peak plasma levels within 1-3 hours, so administering at 2:50pm will provide therapeutic coverage during and immediately after the procedure 2
Postoperative Resumption
Resume the usual Madopar dosing schedule as soon as the patient is able to take oral medications postoperatively 1
If there is any delay in resuming oral intake, observe the patient carefully for symptoms resembling NMS, including rigidity, altered consciousness, and autonomic instability 1
The usual daily dosage should be administered as soon as oral medication is feasible 1
Critical Pitfall to Avoid
Never abruptly discontinue or significantly delay levodopa doses in Parkinson's disease patients, as this can precipitate a life-threatening NMS-like syndrome with severe rigidity, hyperthermia, and altered mental status 1
The risk of acute parkinsonian crisis from missing doses far outweighs any theoretical anesthetic concerns for a short procedure like DSA 1