A hypertensive reaction induced by concurrent use of selegiline and dopamine.

OBJECTIVE: To describe a hypertensive reaction induced by concurrent use of selegiline and dopamine. CASE SUMMARY: A 75-year-old critically ill white man who was receiving selegiline 5 mg twice daily for Parkinson's disease was initiated on an intravenous dopamine infusion for decreased urine output and hypotension. Within minutes of starting the dopamine infusion, the patient's systolic blood pressure increased from 105 to 228 mm Hg. Similar reactions occurred during two subsequent rechallenges. DISCUSSION: Since monoamine oxidase is involved in the metabolism of catecholamines, selegiline may have affected the metabolism of the dopamine administered to the patient. Although selegiline is known to be a monoamine oxidase inhibitor specific for type B, evidence exists stating that selegiline may not be as specific as previously thought. CONCLUSIONS: Dopamine should be used cautiously, if at all, in patients who are chronically receiving selegiline or who have received selegiline within the prior two weeks.

Neuromuscular blocking agents in the neurosurgical intensive care unit.

The long-term administration of neuromuscular blocking (NMB) agents in the ICU has increased in frequency the last several years. NMB agents in the ICU patient facilitate intubation and ventilatory support, decrease oxygen demand and consumption, facilitate bedside procedures and diagnostics, and potentially decrease intracranial pressure. However, NMB agents have extensive adverse effect profiles and require close monitoring. Two major classes of NMB agents exist: depolarizing and nondepolarizing. Depolarizing NMB agents work by mimicking the effect of acetylcholine at the nicotinic cholinergic receptor. Continuous depolarization inhibits repolarization, resulting in paralysis. Nondepolarizing NMB agents induce muscle paralysis by their competitive antagonism at the nicotinic cholinergic receptor. The neurosurgeon must be aware that NMB agents are paralytics only and should only be used in patients who are sedated and receiving adequate analgesia. Appropriate drug selection demands a thorough knowledge and understanding of each patient's neurologic, metabolic, and cardiovascular status and the hemodynamic, autonomic, pharmacokinetic, pharmacodynamic, and cost profiles of the NMB agents.