Should the 4 pm dose of Madopar (Levodopa/Benserazide) be withheld for a patient about to undergo DSA under general anesthesia?

Perioperative Management of Madopar for DSA Under General Anesthesia

Continue Madopar throughout the perioperative period and administer the 4 PM dose as soon as the patient can safely take oral medication post-procedure, even if delayed by a few hours. 1

Rationale for Continuation

The FDA label for levodopa explicitly states: "If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth." 1 This is the definitive guidance for your situation.

• DSA (Digital Subtraction Angiography) is typically a short procedure (30-90 minutes), making the risk-benefit calculation favor continuation rather than abrupt withdrawal 1
• Abrupt discontinuation of levodopa carries serious risks, including sporadic cases of hyperpyrexia, confusion, and symptoms resembling neuroleptic malignant syndrome (NMS) 1
• The patient should be observed carefully if abrupt reduction or discontinuation is required, especially given the neurological implications 1

Practical Management Strategy

Immediate Actions (Next 10 Minutes):

• Inform the anesthesiologist that the patient takes Madopar and had their last dose at 11 AM 1
• Proceed with the DSA as planned - do not delay the procedure for medication administration 1
• The 4-hour gap since the last dose (11 AM to 3 PM) is acceptable for a short procedure 1

Post-Procedure Management:

• Administer the 4 PM dose as soon as the patient is alert and can safely swallow - this may be 5 PM, 6 PM, or whenever oral intake is permitted 1
• A delay of 1-3 hours in the scheduled dose is far safer than complete omission 1
• Resume the usual daily dosage immediately once the patient can take oral medication 1

Critical Safety Considerations

Withdrawal Risks:

• Missing multiple doses creates risk of acute parkinsonian crisis, which can manifest as severe rigidity, hyperpyrexia, altered consciousness, and autonomic instability 1
• These complications are more dangerous than a brief delay in dosing 1

Anesthetic Interactions:

• Levodopa can be safely continued during general anesthesia when oral intake is possible 1
• Standard anesthetic agents used for DSA (propofol, fentanyl, midazolam) do not have absolute contraindications with levodopa 2
• The anesthesiologist should be aware of potential for hypotension and arrhythmias, which are manageable 2

Common Pitfalls to Avoid

• Do not withhold the evening or next morning doses - this compounds the problem and increases NMS risk 1
• Do not assume the patient can "skip a dose safely" - Parkinson's patients on chronic levodopa therapy are dependent on regular dosing 1
• Do not delay resumption waiting for "perfect" timing - give the dose when safe to do so, even if off-schedule 1

If Oral Route Temporarily Unavailable:

• If the patient cannot take oral medication for an extended period post-procedure (unlikely with DSA), consider nasogastric administration of crushed Madopar or discuss alternative dopaminergic support with neurology 1
• The usual daily dosage should be administered as soon as oral medication is feasible 1