Mild to moderate pain may be experienced at the site of injection.
The major side effects of atropine can be attributed to antimuscarinic action. These include dryness of the mouth, blurred vision, photophobia, confusion, headache, dizziness, tachycardia, palpitations, flushing, urinary hesitance or retention, constipation, abdominal distention, nausea, vomiting, loss of libido, and impotency. Anhidrosis may produce heat intolerance and impairment of temperature regulation in a hot environment. Larger or toxic doses may produce such central effects as restlessness, tremor, fatigue, locomotor difficulties, delirium, followed by hallucinations, depression, and, ultimately, medullary paralysis and death. Large doses can also lead to circulatory collapse. In such cases, blood pressure declines and death due to respiratory failure may ensue following paralysis and coma. Hypersensitivity reactions will occasionally occur with atropine; these are usually seen as skin rashes, on occasion progressing to exfoliation.
Pralidoxime may cause blurred vision, diplopia and impaired accommodation, dizziness, headache, drowsiness, nausea, tachycardia, increased systolic and diastolic blood pressure, hyperventilation, decreased renal function, and muscular weakness when given parenterally to normal volunteers who have not been exposed to anticholinesterase poisons. In actual cases of poisoning, it is very difficult to differentiate some of the toxic effects produced by atropine or the organophosphate compound from those of pralidoxime chloride.
Excitement and manic behavior immediately following recovery of consciousness after organophosphorous poisoning treated with pralidoxime chloride have been reported in several cases. However, similar behavior has occurred in cases that were not treated with pralidoxime.3,5,6
Elevations in SGOT and/or SGPT enzyme levels were observed in one of six normal volunteers given 1200 mg of pralidoxime chloride intramuscularly, and in 4 of 6 volunteers given 1800 mg intramuscularly. Levels returned to normal in about two weeks.
Transient elevations in creatine phosphokinase were observed in all normal volunteers given the drug. A single intramuscular injection of 330 mg in 1 mL in rabbits caused myonecrosis, inflammation, and hemorrhage.
Atropine and Pralidoxime Chloride
When atropine and pralidoxime are used together, the signs of atropinization may occur earlier than might be expected when atropine is used alone.