Medicines & Supplements A to Z > Atropine


Last updated on 13/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  




DRUG CLASS: Antispasmodics, Antidotes

SUB CLASS: Anticholinergics

USED FOR: Organophosphates poisoning, Amblyopia, Induction of mydriasis, Bradycardia, Preanesthesia

– 1% (eye drops)
– 600mcg/ml, 1mg/ml (injections)

What is Atropine for?

Atropine belongs to a class of medications called anticholinergics. It works by inhibiting a neurotransmitter in the brain to control different muscles inside our body. It is indicated for the treatment of amblyopia and induction of mydriasis. Also, it can be used for preanesthetic medication to inhibit salivation, treatment of symptomatic bradycardia, as well as an antidote for organophosphate poisoning.

How to use it?

Atropine can be injected intravenously (IV)/ intramuscularly (IM)/ subcutaneously (SubQ), or applied into the eyes. It can also be used endotracheally.

For eye drops, lie down or tilt your head back first. With your index finger, pull down the lower lid of your eye. Hold the dropper close to your eye with the other hand, and drop 1 drop into your eyes between your lower lid and eyeball. Gently close your eyes. Place your index finger over the inner corner of your eye for 1-2 minutes.

For amblyopia:
Instill 1 eye drop in the non-amblyopic eye once daily on weekends.

For induction of mydriasis:
Instill 1 eye drop in the eye 40 minutes prior to intended maximal dilation time, up to once or twice daily.

For acute symptomatic bradycardia:
IV / IM: 0.5-1 mg every 3-5 minutes, up to maximum 3 mg.
ET: 1-2 mg every 3-5 minutes, up to maximum 3 mg.

For organophosphate poisoning:
IV / IM / ET: 1-6 mg depending on severity.

For preanesthetic inhibition of salivation and secretions:
IV / IM / SubQ: 0.5-1 mg 30-60 minutes preoperatively. Repeat as needed every 4-6 hours, up to maximum 3 mg.

What are the side effects of Atropine?

Common side effects of Atropine eye drops include eye pain and stinging on administration, blurred vision, photophobia, increased heart rate and blood pressure. 

Common side effects of Atropine injections include dry mouth, blurred vision, photophobia, and increased heart rate.

Who should not take Atropine?

– People who are allergic to Atropine or any component of the formulation
– Patients with primary glaucoma or or tendency toward closed angle glaucoma

Pharmacist Tips:

– Avoid driving or other activities requiring clear vision until you know how you respond to this drug.
– Protect your eyes in bright lights, such as wearing sunglasses.
– Wash your hands before and after using the eye drops.
– Remove contact lenses prior to administration, and wait 15 minutes before reinserting. 

Common dosing schedule:

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Atropine may interact with:
– Monoamine oxidase inhibitors, e.g. Selegiline, Rasagiline
– Anticholinergics, e.g. Ipratropium, Tiotropium
– Potassium, e.g. Potassium chloride, Potassium citrate
– Opioids, e.g. Tramadol, Codeine, Fentanyl

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Atropine in Hong Kong?

In Hong Kong, Atropine Eye Drop is a medicine under supervised sales and can be purchased under the supervision of a pharmacist from any pharmacies in Hong Kong. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.  

In Hong Kong, Atropine Injection is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Atropine in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.