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Protopam Chloride Side Effects

Generic name: pralidoxime

Medically reviewed by Last updated on May 11, 2022.

Note: This document contains side effect information about pralidoxime. Some of the dosage forms listed on this page may not apply to the brand name Protopam Chloride.

For the Consumer

Applies to pralidoxime: injection powder for solution

Side effects requiring immediate medical attention

Along with its needed effects, pralidoxime (the active ingredient contained in Protopam Chloride) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking pralidoxime:

More common

  • Blurred or double vision
  • change in near or distance vision
  • difficult or rapid breathing
  • difficulty in focusing the eyes
  • difficulty with speaking
  • dizziness
  • fast, pounding, or irregular heartbeat or pulse
  • muscle stiffness or weakness
  • pain at the injection site (after injection into a muscle)

Incidence not known

  • Deep or fast breathing with dizziness
  • numbness of the feet, hands, and around the mouth

Side effects not requiring immediate medical attention

Some side effects of pralidoxime may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to pralidoxime: intravenous powder for injection


Frequency not reported: Tachycardia, increased systolic and diastolic blood pressure[Ref]


Frequency not reported: Muscular weakness[Ref]

Nervous system

Frequency not reported: Drowsiness[Ref]


Frequency not reported: Hyperventilation[Ref]


Frequency not reported: Blurred vision, diplopia, impaired accommodation[Ref]


Frequency not reported: Nausea[Ref]


Frequency not reported: Transient elevations of creatine phosphokinase


SGOT and SGPT levels returned to normal after about 2 weeks.[Ref]

Frequency not reported: Elevations in SGOT and/or SGPT enzymes[Ref]


Frequency not reported: Pain at the injection site[Ref]

Mild to moderate pain at the injection site occurs 40 to 60 minutes after intramuscular injection.[Ref]


1. "Product Information. Protopam Chloride (pralidoxime)." Baxter Healthcare Corporation (2001):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.