From the FDA Drug Label
Neostigmine methylsulfate injection is contraindicated in patients with: • known hypersensitivity to neostigmine methylsulfate (known hypersensitivity reactions have included urticaria, angioedema, erythema multiforme, generalized rash, facial swelling, peripheral edema, pyrexia, flushing, hypotension, bronchospasm, bradycardia and anaphylaxis). • peritonitis or mechanical obstruction of the intestinal or urinary tract.
A contraindication to Neostigmine administration is:
- Known hypersensitivity to neostigmine methylsulfate
- Peritonitis or mechanical obstruction of the intestinal or urinary tract 1 1
From the Research
Neostigmine should not be administered to patients with new-onset heart block, a history of second-degree heart block, or following bowel resection with primary anastomosis, as these conditions are considered contraindications to its use. Other important contraindications to consider when administering neostigmine include:
- Mechanical bowel or urinary tract obstruction
- Peritonitis
- Recent gastrointestinal or bladder surgery
- Bradycardia (heart rate < 60 beats per minute)
- Asthma (active bronchospasm)
- Seizure disorders Before administering neostigmine, it is crucial to ensure the patient has no signs of residual neuromuscular blockade, as this could lead to paradoxical muscle weakness. Always have atropine readily available when giving neostigmine to counteract potential cholinergic side effects, such as bradycardia, bronchospasm, or excessive salivation and lacrimation 2. The reason for these contraindications is that neostigmine, as an acetylcholinesterase inhibitor, increases acetylcholine levels, which can exacerbate obstructions by increasing smooth muscle contractions in the gastrointestinal and urinary tracts, worsen bradycardia, trigger bronchospasm in asthmatics, and potentially lower the seizure threshold in susceptible individuals. It is also important to note that while neostigmine can be effective in treating acute colonic pseudo-obstruction, its use should be approached with caution in patients with certain comorbidities, and careful consideration should be given to the potential risks and benefits of its administration 3, 4.