Intravenous (IV), Intramuscular (IM), Subcutaneous (SC), Endotracheal (ET), Ophthalmic (Topical)
- Injection: 0.6 mg/mL (1 mL ampoule), 1 mg/mL (1 mL ampoule)
- Ophthalmic solution: 1% w/v eye drops (5 mL, 10 mL bottles)
Note: Paediatric oral drops and prefilled syringes are NOT routinely available in India.
INDICATIONS + DOSING — FOR CLINICIAN USE ONLY
Primary Indications (Approved / Standard in India)
- Symptomatic Bradycardia (Haemodynamically Unstable)
Parameter Recommendation
Starting dose 0.5–1 mg IV bolus
Titration Repeat 0.5–1 mg IV every 3–5 minutes until adequate heart rate achieved
Usual maintenance dose Not applicable (acute use only)
Maximum dose 3 mg total (vagolytic effect complete at this dose)
Key Clinical Notes:
- First-line agent for symptomatic sinus bradycardia and high-grade AV block
- Doses <0.5 mg may cause paradoxical bradycardia — avoid underdosing in adults
- Ineffective in denervated hearts (cardiac transplant) and infranodal blocks
- Not effective for hypothermic bradycardia — focus on rewarming
- Organophosphate / Carbamate Poisoning
Parameter Recommendation
Starting dose 2–5 mg IV bolus (severe cases may need higher initial dose)
Titration Double the dose every 5–10 minutes until muscarinic symptoms controlled
Usual maintenance dose Continuous IV infusion 0.5–2 mg/hour (10–20% of total loading dose per hour)
Maximum dose No fixed maximum — titrate to clinical endpoints
Clinical Endpoints for Atropinisation:
- Drying of bronchial secretions (primary endpoint)
- Pupils no longer pinpoint (but do NOT use pupil size as primary titration target)
Key Clinical Notes:
- Administer with pralidoxime (PAM) for organophosphate poisoning
- Very large cumulative doses (100+ mg over 24–48 hours) may be required in severe poisoning
- Continue infusion until patient can maintain atropinisation without redosing for 24 hours
- Do not delay atropine for poisoning — it is life-saving
- Pre-anaesthetic Medication (Reduction of Secretions and Vagal Bradycardia Prevention)
Parameter Recommendation
Starting dose 0.3–0.6 mg IM or SC
Titration Not applicable
Usual maintenance dose Single pre-operative dose
Maximum dose 0.6 mg
Key Clinical Notes:
- Administer 30–60 minutes before anaesthesia induction (IM/SC)
- Less commonly used in modern anaesthesia practice — glycopyrrolate often preferred (less CNS effects, longer duration)
- Use with caution in elderly and patients with coronary artery disease
- Mydriasis and Cycloplegia (Ophthalmic Use)
Parameter Recommendation
Starting dose 1 drop of 1% solution in affected eye(s)
Titration Not applicable
Usual maintenance dose 1–2 drops once or twice daily
Maximum dose As per ophthalmology protocol
Key Clinical Notes:
- Produces prolonged mydriasis (7–10 days) and cycloplegia (up to 14 days)
- Used for cycloplegic refraction in children, uveitis treatment, and pre/post-operative mydriasis
- NOT suitable for routine fundoscopy where shorter-acting mydriatics (tropicamide) are preferred
- Compress lacrimal sac for 1–2 minutes after instillation to reduce systemic absorption
Secondary Indications – Adults Only (Off-label)
- Asystole / Pulseless Electrical Activity (PEA) — NO LONGER RECOMMENDED
- Atropine is NO LONGER part of standard ACLS protocols for asystole or PEA
- Historical use has been discontinued based on lack of survival benefit
- Focus on high-quality CPR, adrenaline, and reversible cause identification
- Reversal of Neuromuscular Blockade (with Neostigmine) — OFF-LABEL (but common practice)
- Starting dose: 0.6–1.2 mg IV (given with neostigmine 2.5–5 mg)
- Titration: Not applicable
- Usual maintenance dose: Single dose
- Specialist only (Anaesthesiology)
- Evidence: Standard anaesthesia practice; prevents muscarinic side effects of neostigmine
PAEDIATRIC DOSING (Specialist Only)
Primary Indications (Approved / Standard in India)
- Symptomatic Bradycardia (Paediatric Advanced Life Support)
Age/Weight Starting Dose Route Maximum Single Dose Maximum Total Dose
Neonates 0.02 mg/kg IV/IO Minimum 0.1 mg 0.04 mg/kg
Infants (<1 year) 0.02 mg/kg IV/IO 0.5 mg 1 mg
Children (1–12 years) 0.02 mg/kg IV/IO 0.5 mg 1 mg
Adolescents (>12 years) 0.02 mg/kg IV/IO 1 mg 2 mg
Parameter Recommendation
Starting dose 0.02 mg/kg IV/IO
Titration Repeat every 3–5 minutes if bradycardia persists
Usual maintenance dose Not applicable (acute use)
Maximum dose Child: 1 mg total; Adolescent: 2 mg total
Endotracheal (ET) Route (if IV/IO not available):
- Dilute in 3–5 mL normal saline before administration
- Absorption is unpredictable — establish IV/IO access as soon as possible
- Organophosphate / Carbamate Poisoning
Parameter Recommendation
Starting dose 0.02–0.05 mg/kg IV (minimum 0.1 mg)
Titration Repeat every 5–10 minutes until secretions dry
Usual maintenance dose Continuous infusion may be needed — 0.02–0.08 mg/kg/hour
Maximum dose No fixed maximum — titrate to clinical response
Key Clinical Notes:
- Administer with pralidoxime
- Endpoint: Drying of secretions (NOT pupil size or heart rate alone)
- Specialist only (Paediatric Emergency/ICU)
- Cycloplegic Refraction / Uveitis (Ophthalmic)
Age Dose Frequency
3 months – 3 years 1 drop of 0.5% solution Once daily for 1–3 days before examination
3 years 1 drop of 1% solution Once daily for 1–3 days
Key Clinical Notes:
- Compress lacrimal punctum after instillation to minimize systemic absorption
- Monitor for systemic anticholinergic effects (flushing, fever, tachycardia)
- Not recommended below 3 months of age except under specialist ophthalmology supervision
Secondary Indications – Paediatric Doses (Off-label)
- Pre-anaesthetic Use — OFF-LABEL (less common in modern practice)
- Starting dose: 0.01–0.02 mg/kg IM
- Titration: Not applicable
- Usual maintenance dose: Single dose
- Duration: 30–60 minutes before induction
- Specialist only (Paediatric Anaesthesiology)
- Evidence: Standard paediatric anaesthesia texts; glycopyrrolate often preferred
Safety Monitoring (All Paediatric Use):
- Heart rate and rhythm monitoring
- Respiratory status (especially in poisoning)
- Temperature monitoring (risk of hyperthermia)
- Mental status assessment for anticholinergic toxicity
Minimum dose of 0.1 mg per dose recommended in neonates and infants to avoid paradoxical bradycardia.
- No dosage adjustment required
- Atropine is primarily metabolized hepatically with minimal renal excretion of unchanged drug
- Safe to use in renal impairment including dialysis patients
- Mild impairment: No dosage adjustment required
- Moderate impairment: Use with caution; standard doses generally tolerated
- Severe impairment (Child-Pugh C): Use with caution; may have increased sensitivity to anticholinergic effects due to reduced hepatic metabolism; monitor for excessive anticholinergic effects
- Known hypersensitivity to atropine or belladonna alkaloids
- Narrow-angle glaucoma (ophthalmic use contraindicated; systemic use with extreme caution)
- Obstructive gastrointestinal disease (pyloric stenosis, paralytic ileus, toxic megacolon)
- Obstructive uropathy with urinary retention
- Myasthenia gravis (may worsen weakness by blocking compensatory muscarinic effects)
- Severe ulcerative colitis or toxic megacolon
Note: In life-threatening emergencies (bradycardia, poisoning), relative contraindications should not delay treatment.
- Elderly patients — increased sensitivity to CNS effects (confusion, delirium)
- Cardiovascular disease — may precipitate tachyarrhythmias or myocardial ischaemia
- Hyperthyroidism — exaggerated tachycardic response
- Fever or high ambient temperature — risk of hyperthermia (inhibits sweating)
- Chronic pulmonary disease — thickened secretions may worsen airway obstruction
- Prostatic hypertrophy — risk of acute urinary retention
- Down syndrome — increased sensitivity to anticholinergic effects
- Gastro-oesophageal reflux disease
Parameter Recommendation
Risk category No formal Indian classification; generally considered relatively safe in emergencies
Placental transfer Crosses placenta; may cause fetal tachycardia
Preferred alternatives None in emergency situations — use atropine when indicated
When may be used Life-threatening bradycardia, poisoning, anaesthesia adjunct
Monitoring Continuous fetal heart rate monitoring when used intrapartum; maternal heart rate and rhythm
Parameter Recommendation
Compatibility Compatible with breastfeeding (single/emergency doses)
Expected drug levels in milk Low; minimal amounts excreted
Preferred alternatives Not applicable in emergency settings
What to monitor in infant Dry mouth, feeding difficulty, constipation, irritability, decreased urine output (with repeated maternal doses)
Note: May reduce milk production with repeated doses due to anticholinergic effects.
- Starting dose: 0.3–0.5 mg IV for bradycardia (lower end of adult range)
- Titration: Slower titration with longer intervals between doses
- Pronounced CNS effects (confusion, agitation, hallucinations, delirium)
- Increased risk of urinary retention
- Tachyarrhythmias and myocardial ischaemia
- Constipation and faecal impaction
- Heat intolerance and hyperthermia
- Falls (due to confusion, visual disturbance)
- Avoid ophthalmic use unless essential — prolonged cycloplegia increases fall risk
Interacting Drug Effect Mechanism Management
Cholinesterase inhibitors (neostigmine, pyridostigmine, donepezil, rivastigmine) Antagonistic effect Opposing actions at muscarinic receptors Expected when atropine used to counter muscarinic side effects; avoid in myasthenia gravis treatment
Other anticholinergics (antihistamines, tricyclic antidepressants, antipsychotics, oxybutynin) Additive anticholinergic toxicity Cumulative muscarinic blockade Avoid combination; if necessary, monitor for anticholinergic syndrome
Potassium chloride (slow-release oral preparations) Increased risk of GI ulceration Delayed GI transit prolongs contact time Avoid slow-release potassium during atropine use; use liquid preparations if needed
Interacting Drug Effect Management
Beta-blockers Atropine may be needed to counteract bradycardia; concurrent use may cause unpredictable heart rate response Monitor heart rate closely
Digoxin Atropine may increase digoxin absorption (reduced GI motility) Monitor for digoxin toxicity if atropine used repeatedly
Amantadine Additive anticholinergic effects Monitor for confusion and urinary retention
Nitrates May have additive hypotensive effects initially followed by tachycardia Monitor blood pressure and heart rate
Opioids Additive constipation and urinary retention Prophylactic bowel regimen; monitor voiding
Topical ophthalmic beta-blockers Systemic beta-blockade may be antagonized by atropine Monitor for desired ophthalmic effect
- Blurred vision and photophobia
- Tachycardia and palpitations
- Urinary hesitancy or retention
- Constipation and reduced gastrointestinal motility
- Flushing and warm dry skin
- Mydriasis (even with systemic use)
- Mild confusion or restlessness (especially elderly)
- Anticholinergic toxicity/syndrome: Hyperthermia, severe agitation, hallucinations, seizures, coma — requires supportive care; consider physostigmine in severe cases
- Acute angle-closure glaucoma: Especially with ophthalmic use in predisposed individuals — requires immediate ophthalmology referral
- Severe tachyarrhythmias: Atrial fibrillation, supraventricular tachycardia, ventricular arrhythmias — more common in cardiac disease
- Hyperthermia/heat stroke: Due to inhibition of sweating — especially in hot environments or with fever
- Complete urinary retention: Especially in elderly men with prostatic hypertrophy
- Paralytic ileus: With repeated high doses
Baseline:
- Heart rate and rhythm (ECG if available)
- Respiratory rate and pattern (in poisoning)
- Pupil size (in poisoning — but not primary titration target)
After Administration:
- Heart rate every 5 minutes during acute use
- Blood pressure monitoring
- Respiratory secretions (in OP poisoning — primary endpoint)
- Mental status (especially elderly)
- Temperature (risk of hyperthermia)
For Ophthalmic Use:
- Intraocular pressure in susceptible patients
- Systemic absorption signs (especially children): flushing, fever, tachycardia, dry skin
Long-term:
- Not typically applicable — atropine is used acutely
- In OP poisoning, continue monitoring for 24–48 hours after stopping infusion
Injection:
- Atropine Sulphate IP (generic — multiple manufacturers)
Ophthalmic:
- Atropine Eye Drops 1% (generic — multiple manufacturers)
- Tropicacyl-A (combination with tropicamide — limited use)
- Injection 0.6 mg/mL (1 mL ampoule): ₹3–₹12
- Injection 1 mg/mL (1 mL ampoule): ₹5–₹15
- Eye drops 1% (5 mL): ₹20–₹50
- Eye drops 1% (10 mL): ₹35–₹80
- Available in government hospital supplies (essential for poisoning management and emergency care)
- Avoid underdosing in bradycardia: Doses <0.5 mg in adults may cause paradoxical bradycardia due to central vagal stimulation — always use at least 0.5 mg per dose
- OP poisoning endpoint is secretion drying, NOT pupil dilation: Pupils may remain constricted despite adequate atropinisation; titrate to clear lung sounds and dry bronchial secretions
- Do not delay atropine in severe OP poisoning: Large doses are often required — some patients need hundreds of milligrams over several days; underdosing leads to treatment failure
- Glycopyrrolate preferred for pre-anaesthetic use: Does not cross blood-brain barrier (fewer CNS effects) and has longer duration; atropine reserved for specific indications
- Shorter-acting mydriatics preferred for routine eye exams: Tropicamide (onset 20–30 minutes, duration 4–6 hours) is preferred over atropine (duration 7–14 days) for routine fundoscopy
- Anticholinergic toxicity in elderly: "Blind as a bat, dry as a bone, red as a beet, mad as a hatter, hot as a hare" — recognize this syndrome early and provide supportive care
atropine; anticholinergic; bradycardia; organophosphate poisoning; carbamate poisoning; emergency medicine; mydriatic; NLEM India; parasympatholytic; resuscitation
RxIndia v1.0 — 08 Apr 2025
- CDSCO approved prescribing information
- Indian Pharmacopoeia 2018
- National List of Essential Medicines (NLEM) India 2022
- AIIMS Emergency Medicine Protocols
- ICMR Guidelines on Pesticide Poisoning Management
- IAP Paediatric Advanced Life Support Guidelines
- Goodman & Gilman's The Pharmacological Basis of Therapeutics