Indications
Atropine Sulfate injection is a hospital medicine used to treat a dangerously slow heart rate (symptomatic bradycardia), as part of resuscitation, before anaesthesia to reduce saliva and airway secretions and protect the heart rate, together with Neostigmine when reversing muscle relaxants after surgery, and as an antidote for poisoning by organophosphate insecticides, nerve agents and some mushrooms.
How It Works
Atropine is an antimuscarinic (anticholinergic) medicine. It blocks acetylcholine, a nerve chemical that slows the heart and increases secretions in the mouth, airways and gut. By blocking it, atropine speeds up the heart, dries secretions, relaxes smooth muscle and counteracts the effects of organophosphate poisoning.
Dosage and Administration
Atropine injection is given by a doctor or nurse into a vein, muscle or under the skin, and in emergencies sometimes through other routes. The dose depends on the reason for use, body weight and response; in organophosphate poisoning repeated, often large doses are given until secretions dry and breathing improves. Dosing is as prescribed and is closely monitored.
Interactions
- Other anticholinergic medicines, such as tricyclic antidepressants, antihistamines, antipsychotics and Disopyramide, increase side effects such as dry mouth, urinary retention and confusion.
- It may reduce the effect of Metoclopramide and Domperidone.
- It may slow the absorption of oral medicines by slowing the gut.
Contraindications
In emergencies such as organophosphate poisoning or life threatening slow heart rate there are no absolute contraindications. In routine use it is avoided in narrow angle glaucoma, myasthenia gravis (except with Neostigmine), bowel obstruction or paralytic ileus, severe ulcerative colitis, urinary retention from an enlarged prostate, and fast heart rhythms.
Side Effects
Common effects are dry mouth, blurred vision, dilated pupils, sensitivity to light, flushing, dry skin, fast heartbeat, difficulty passing urine, constipation and reduced sweating. Higher doses may cause confusion, agitation, hallucinations and high temperature, especially in older people and children.
Tell the nurse or doctor immediately if there is chest pain, a very fast or irregular heartbeat, severe confusion, high fever, eye pain, or inability to pass urine.
Pregnancy and Lactation
Atropine crosses the placenta and may speed up the baby’s heart rate. It is used in pregnancy when the doctor considers it necessary, especially in emergencies. Small amounts pass into breast milk; a single dose is unlikely to cause harm.
Precautions and Warnings
- Heart rate, rhythm and blood pressure are monitored.
- Used with care in heart disease, high blood pressure, overactive thyroid, fever and hot environments, reflux and in older adults and children.
- Vision may be blurred after a dose; do not drive until it clears.
Overdose
Overdose causes very dry mouth, hot flushed dry skin, high fever, dilated pupils, fast heartbeat, agitation, hallucinations, fits and coma. Further doses are stopped and the medical team gives supportive care; Physostigmine may be used in specialist settings.
Therapeutic Class
Antimuscarinic (anticholinergic), antidote for organophosphate poisoning.
Storage
Hospital medicine: store as directed on the pack, usually below 25°C, protected from light, out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.