Adverse Reactions
Common adverse reactions of atropine include dry mouth, blurred vision, photophobia, tachycardia, flushed skin, constipation, difficulty with urination, inability to perspire appropriately, delirium or coma (McLendon & Preuss, 2023).
Precautions (Pfizer, 2022)
Atropine may cause adverse effects in patients with the following conditions:
- Known hypersensitivity
- Tachycardia
- Hyperthermia: atropine may inhibit sweating that can lead to heat-related injury
- Suspected glaucoma: atropine may precipitate acute glaucoma
- Pyloric stenosis: atropine may cause complete obstruction
- Prostatic hypertrophy: atropine may cause urinary retention
Atropine should be used with caution in patients with the following conditions:.
- Cardiovascular disease: Use atropine with caution in patients with myocardial infarction, heart failure, tachyarrhythias, and/or hypertension.
- Chronic lung disease: atropine may cause thickening of bronchial secretions.
- Liver or renal impairment may prolong the effects of atropine.
Atropine should also be used with caution in patients with hiatal hernia associated with reflux esophagitis, hyperthyroidism, myasthenia gravis, neuropathy, and urinary retention.
Drug-Drug Interactions (Pfizer, 2022)
The action of atropine may be enhanced by tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), phenothiazine, amantadine, some antihistamines, butyrophenones, and disopyramide.
Overdose (Pfizer, 2022)
The following symptoms could signal overdose: palpitations, dilated pupils, difficulty swallowing, hot dry skin, thirst, dizziness, restlessness, tremor, fatigue, and ataxia. Toxic doses can cause palpitations, restlessness, hallucinations, delirium, and coma. Severe overdose may result in circulatory collapse, respiratory failure, paralysis, and coma. Treatment of toxic overdose includes a short-acting barbiturate or diazepam as needed for excitement or convulsions. Physostigmine (1 to 4 mg) is an atropine antidote administered by slow IV injection to treat delirium and coma. Repeat doses may be required.