Side Effects of Pralidoxime
Pralidoxime can cause several side effects including blurred vision, diplopia, dizziness, headache, drowsiness, nausea, tachycardia, increased blood pressure, hyperventilation, and muscular weakness when administered parenterally. 1
Common Side Effects
- Pain at injection site: Mild to moderate pain may occur 40-60 minutes after intramuscular injection 1
- Visual disturbances: Blurred vision, diplopia (double vision), and impaired accommodation 1
- Neurological effects: Dizziness, headache, and drowsiness 1
- Gastrointestinal effects: Nausea 1
- Cardiovascular effects: Tachycardia and increased systolic and diastolic blood pressure 1
- Respiratory effects: Hyperventilation 1
- Musculoskeletal effects: Muscular weakness 1
Laboratory Abnormalities
- Transient elevations in liver enzymes (SGOT/SGPT) were observed in some individuals receiving pralidoxime, with levels returning to normal in approximately 2 weeks 1
- Transient elevations in creatine phosphokinase have been observed in all normal volunteers given the drug 1
Special Considerations
Interaction with Atropine
- When atropine and pralidoxime are used together, signs of atropinization may occur earlier than expected with atropine alone 1
- This effect is especially pronounced if the total dose of atropine has been large and pralidoxime administration has been delayed 1
Neuropsychiatric Effects
- Excitement and manic behavior immediately following recovery of consciousness have been reported in several cases 1
- However, similar behavior has occurred in organophosphate poisoning cases not treated with pralidoxime 1
Pharmacological Considerations
- Pralidoxime's effectiveness is time-dependent, with better outcomes when administered early before "aging" of the phosphorylated enzyme occurs 2
- The American Society of Anesthesiologists (ASA) notes that mild transient hepatic damage can develop in higher dose ranges 3
Pediatric Considerations
- Side effects in children may include those seen in adults, but slow intravenous administration is recommended to minimize adverse effects 3
- In children, side effects such as hypertension, headache, blurred vision, nausea, and vomiting may occur with pralidoxime chloride 3, 4
Clinical Monitoring
- Patients receiving pralidoxime should be monitored for signs of atropinization when co-administered with atropine 1
- Monitoring of liver enzymes and creatine phosphokinase may be warranted in patients receiving high doses 1
While pralidoxime is an important antidote for organophosphate poisoning, clinicians should be aware of these potential side effects and monitor patients accordingly during treatment.