What Is Atropine?

Atropine (Atropine Sulfate) is an anticholinergic medication that has been used in medicine for decades. It is FDA-approved for treating symptomatic bradycardia (abnormally slow heart rate), organophosphate and nerve agent poisoning, reducing salivary and bronchial secretions before surgery, and producing cycloplegia and mydriasis (pupil dilation) for ophthalmic examinations. In ophthalmology, it is also used to treat amblyopia (lazy eye) in children.

Atropine is increasingly used off-label as low-dose eye drops (0.01%–0.05%) to slow the progression of myopia (nearsightedness) in children, a growing area of research and clinical use.

How does Atropine work?

Atropine works as a competitive, reversible antagonist of muscarinic acetylcholine receptors (M1 through M5). By blocking acetylcholine at parasympathetic nerve endings, Atropine produces several effects throughout the body: it increases heart rate, reduces secretions (saliva, bronchial, and gastrointestinal), relaxes smooth muscle, and dilates the pupils. In the eye specifically, it paralyzes the ciliary muscle (cycloplegia) and dilates the pupil (mydriasis), which is useful for eye exams and treating certain eye conditions.

What doses are available for Atropine?

• Injectable Solution: 0.05 mg/mL, 0.1 mg/mL, 0.4 mg/mL, and 1 mg/mL
• AtroPen Auto-Injector: 0.25 mg, 0.5 mg, 1 mg, and 2 mg
• Ophthalmic Solution: 0.5% and 1%
• Ophthalmic Ointment: 1%
• Low-Dose Ophthalmic (Compounded): 0.01%–0.05% for myopia control in children

How hard is it to find Atropine in stock?

Atropine scores a 45 out of 100 on the Medfinder findability scale, meaning it can be moderately difficult to locate. Injectable formulations of Atropine Sulfate have been on the FDA/ASHP drug shortage list intermittently, with certain prefilled syringe forms on back order through late 2026–2028. Pfizer discontinued Atropine Abboject LifeShield syringes in mid-2025, further tightening supply. Ophthalmic drops are generally easier to find, but specific concentrations may still be spotty at some pharmacies. Using Medfinder can help you quickly locate which pharmacies near you currently have Atropine in stock.

Who Can Prescribe Atropine?

Atropine is prescribed by a wide range of medical specialists depending on its intended use:

• Emergency Medicine physicians — for bradycardia and poisoning emergencies
• Anesthesiologists — to reduce secretions before surgery
• Ophthalmologists — for eye exams, amblyopia treatment, and myopia control
• Cardiologists — for symptomatic bradycardia
• Critical Care / Intensivists — in ICU settings for various indications
• Pediatricians — for myopia control and pediatric indications
• Toxicologists — for poisoning cases
• Palliative Care specialists — to manage secretions at end of life

Is Atropine a controlled substance?

No, Atropine is not a controlled substance. It does not have a DEA schedule and is not subject to the prescribing restrictions that apply to controlled medications. However, it is worth noting that the combination product Diphenoxylate/Atropine (Lomotil), which is used for diarrhea, is classified as a Schedule V controlled substance due to the diphenoxylate component.

Common Side Effects of Atropine

• Dry mouth
• Blurred vision
• Light sensitivity (photosensitivity)
• Rapid heart rate (tachycardia)
• Urinary retention
• Constipation
• Dizziness
• Nausea
• Flushing
• Decreased sweating

Serious side effects can include severe tachycardia or arrhythmias, acute angle-closure glaucoma, hyperthermia, delirium or hallucinations (anticholinergic toxicity), and paralytic ileus. Seek medical attention immediately if you experience any of these.

Alternative Medications to Atropine

• Glycopyrrolate (Robinul) — A quaternary ammonium anticholinergic that does not cross the blood-brain barrier, resulting in fewer CNS side effects. It is 5 times more potent as an anti-sialagogue and is used for secretion reduction and bradycardia.
• Scopolamine (Hyoscine) — An anticholinergic used for motion sickness, nausea, and secretion reduction. Available as a transdermal patch but causes more sedation than Atropine.
• Ipratropium Bromide (Atrovent) — An inhaled anticholinergic bronchodilator for COPD and asthma that does not produce significant systemic anticholinergic effects.
• Cyclopentolate — A shorter-acting cycloplegic and mydriatic eye drop used for eye exams, with effects lasting 4–24 hours compared to Atropine's 1–2 weeks.

Drug Interactions with Atropine

• Other anticholinergic drugs — Additive effects increasing the risk of ileus, urinary retention, and hyperthermia
• Potassium chloride (solid oral forms) — Increased risk of GI ulceration
• Antihistamines (Diphenhydramine, Promethazine) — Additive anticholinergic effects
• Tricyclic antidepressants (Amitriptyline, Nortriptyline) — Additive anticholinergic effects
• Antipsychotics (Chlorpromazine, Quetiapine) — Additive anticholinergic effects
• Opioids — Additive constipation and urinary retention
• GI motility agents (Metoclopramide) — Atropine may reduce their effectiveness
• Topiramate — Increased risk of hyperthermia

Final Thoughts on Atropine

Atropine remains an essential medication in emergency medicine, surgery, ophthalmology, and critical care. While generic Atropine eye drops are relatively affordable at $20–$54 without insurance, injectable formulations face ongoing supply challenges due to manufacturer discontinuations and production issues. The AtroPen auto-injector is significantly more expensive at $300–$800+ per unit. If you're having trouble finding Atropine in stock at your local pharmacy, Medfinder can help you search real-time availability nearby. Always talk to your doctor or pharmacist about alternatives like Glycopyrrolate or Cyclopentolate if your specific Atropine formulation is unavailable.