Atropine Injection BP Minijet

Atropine Sulphate 0.1 mg/ml

Sterile aqueous solution for parenteral administration to humans.

Acute myocardial infarction with AV conduction block due to excess vagal tone (Wenkebach Type I, second-degree AV block) and sinus bradycardia, with associated hypotension and increased ventricular irritability.

Atropine can also be used in cardiopulmonary resuscitation for the treatment of sinus bradycardia accompanied by hypotension, hypoperfusion or ectopic arrhythmias.

Parenteral atropine is indicated as an antisialogogue in anaesthetic premedication to prevent or reduce secretions of the respiratory tract.

During anaesthesia, atropine may be used to prevent reflex bradycardia and restore cardiac rate and arterial pressure resulting from increased vagal activity associated with laryngoscopy, tracheal intubation and intra-abdominal manipulation. It may also be administered to block muscarinic effects when neostigmine is used to counteract muscle relaxants such as tubocurarine.

Parenteral atropine is an antidote for cardiovascular collapse following overdose of anticholinesterases; in the treatment of poisoning from organophosphorous insecticides or from chemical warfare 'nerve' gases and in the treatment of mushroom poisoning.

Adults, children over 12 and the elderly:

Bradyarrhythmias: intramuscular or intravenous, 300 to 600 mcg (0.3 to 0.6 mg) every four to six hours to a total dose of 2 mg.

In cardiac resuscitation, intravenous 500 mcg (0.5 mg) repeated at 5 minute intervals until the desired heart rate is achieved. In asystole, 3 mg may be given intravenously as a once only single dose. If atropine cannot be administered intravenously during resuscitation, 2-3 times the intravenous dose may be administered via an endotracheal tube.

Premedication before anaesthesia: intramuscular or subcutaneous, 300 to 600 mcg (0.3 to 0.6 mg) 30-60 minutes before surgery or the same dose intravenously immediately before surgery.

To control muscarinic side effects of neostigmine: intravenous, 600 to 1200 mcg (0.6 - 1.2 mg).

Anticholinesterase poisoning: intramuscular or intravenous, 1 to 2 mg repeated every 5 to 60 minutes until signs and symptoms disappear, up to a maximum of 100 mg in the first 24 hours.

Children up to the age of 12 years:

The usual intramuscular, intravenous or subcutaneous dose in children is 10 mcg/kg (0.01 mg/kg), but generally not exceeding 400 mcg (0.4 mg). If necessary, these doses may be repeated every 4-6 hours.

Cardiac: for advanced cardiac life support: intravenous, 20mcg/kg (0.02 mg/kg) with a minimum dose of 10 mcg (0.01 mg) repeated at 5 minute intervals, to a maximum dose of 100 mcg (0.1 mg).

Premedication before anaesthesia: intramuscular or subcutaneous; 30-60 minutes before surgery.

Up to 3 kg - 100 mcg (0.1mg)

7 - 9 kg - 200 mcg (0.2mg)

12 - 16 kg - 300 mcg (0.3mg)

Over 20 kg - as for adults.

To control the muscarinic side effects of neostigmine: intravenous; neonates, infants and children - 20 mcg/kg (0.02 mg/kg). Maximum dosage 600 mcg.

Anticholinesterase poisoning: intramuscular or intravenous, 50 mcg/kg (0.05 mg/kg) every 10-30 minutes until muscarinic signs and symptoms disappear.

Contra-indications are not applicable to the use of atropine in life-threatening emergencies (eg. asystole).

Atropine is contraindicated in patients with known hypersensitivity to the drug, obstruction of the bladder neck eg due to prostatic hypertrophy, reflux oesophagitis, closed angle glaucoma, myasthenia gravis (unless used to treat the adverse effects of an anticholinesterase agent), paralytic ileus, severe ulcerative colitis and obstructive disease of the gastrointestinal tract.

Antimuscarinic agents should be used with caution in the elderly and children since these patients may be more susceptible to adverse effects. Atropine should also be used with caution in patients with hyperthyroidism, hepatic or renal disease or hypertension. Use with caution in febrile patients or when ambient temperature is high since antimuscarinics may cause an increase in temperature. Antimuscarinics block vagal inhibition of the SA nodal pacemaker and should thus be used with caution in patients with tachyarrhythmias, congestive heart failure or coronary heart disease. Parenterally administered atropine should be used cautiously in patients with chronic pulmonary disease since a reduction in bronchial secretions may lead to formation of bronchial plugs. Antimuscarinics should be used with extreme caution in patients with autonomic neuropathy.

Antimuscarinics decrease gastric motility, relax the lower oesophageal sphincter and may delay gastric emptying; they should therefore be used with caution in patients with gastric ulcer, oesophageal reflux or hiatus hernia associated with reflux oesophagitis, diarrhoea or GI infection.

The effects of atropine may be enhanced by the concomitant administration of other drugs with anticholinergic activity eg. tricyclic antidepressants, antispasmodics, anti-parkinsonian drugs, some antihistamines, phenothiazines, disopyramide and quinidine. By delaying gastric emptying, atropine may alter the absorption of other drugs.

Atropine crosses the placenta. Studies in humans have not been done and only limited information is available from animal studies. Intravenous administration of atropine during pregnancy or at term may cause tachycardia in the foetus. Atropine should only be administered to pregnant women if the benefits outweigh the risks to the foetus. Trace amounts of atropine appear in the breast milk and may cause antimuscarinic effects in the infant; lactation may be inhibited.

Not applicable; this preparation is intended for use only in emergencies.

Adverse effects are dose-related and usually reversible when therapy is discontinued. In relatively small doses, atropine reduces salivary, bronchial and sweat secretions; dry mouth and anhidrosis may develop, these effects being intensified as the dosage is increased. Reduced bronchial secretion may cause dehydration of residual secretion and consequent formation of thick bronchial plugs that are difficult to eject from the respiratory tract.

Larger doses dilate the pupil and inhibit accommodation of the eye, and block vagal impulses with consequent increase in heart rate with possible atrial arrhythmias, A-V dissociation and multiple ventricular ectopics; parasympathetic control of the urinary bladder and gastrointestinal tract is inhibited, causing urinary retention and constipation. Further increase in dosage inhibits gastric secretion. Anaphylaxis, urticaria and rash occasionally progressing to exfoliation may develop in some patients. Other effects include hallucinations, increased ocular tension, loss of taste, headache, nervousness, drowsiness, weakness, dizziness, flushing, insomnia, nausea, vomiting and bloated feeling. Mental confusion and/or excitement may occur especially in the elderly.

Symptoms: marked dryness of the mouth accompanied by a burning sensation, difficulty in swallowing, pronounced photophobia, flushing and dryness of the skin, raised body temperature, rash, nausea, vomiting, tachycardia and hypertension. Restlessness, tremor, confusion, excitement, hallucinations and delirium may result from CNS stimulation; this is followed by increasing drowsiness, stupor and general central depression terminating in death from circulatory and respiratory failure.

Treatment: In severe cases, physostigmine, 1 to 4 mg, should be administered intravenously, intramuscularly or subcutaneously, the dose may be repeated if necessary since it is rapidly eliminated from the body. Diazepam may be administered for sedation of the delirious patient but the risk of central depression occurring late in the course of atropine poisoning contraindicates large doses of sedative. An adequate airway should be maintained and respiratory failure may be treated with oxygen and carbon dioxide inhalation. Fever is reduced by the application of cold packs or sponging with tepid water. Adequate fluid intake is important. Urethral catheterisation may be necessary. If photophobia is present or likely, the patient should be nursed in a darkened room.

Atropine is an antimuscarinic agent which competitively antagonizes acetylcholine at postganglionic nerve endings, thus affecting receptors of the exocrine glands, smooth muscle, cardiac muscle and the central nervous system.

Peripheral effects include tachycardia, decreased production of saliva, sweat, bronchial, nasal, lachrymal and gastric secretions, decreased intestinal motility and inhibition of micturition.

Atropine increases sinus rate and sinoatrial and AV conduction. Usually heart rate is increased but there may be an initial bradycardia.

Atropine inhibits secretions throughout the respiratory tract and relaxes bronchial smooth muscle producing bronchodilatation.

Following intravenous administration, the peak increase in heart rate occurs within 2 to 4 minutes. Peak plasma concentrations of atropine after intramuscular administration are reached within 30 minutes, although peak effects on the heart, sweating and salivation may occur nearer one hour after intramuscular administration.

Plasma levels after intramuscular and intravenous injection are comparable at one hour. Atropine is distributed widely throughout the body and crosses the blood brain barrier. The elimination half life is about 2 to 5 hours. Up to 50% of the dose is protein bound. It disappears rapidly from the circulation.

Atropine is metabolised in the liver by oxidation and conjugation to give inactive metabolites.

About 50% of the dose is excreted within 4 hours and 90% in 24 hours in the urine, about 30 to 50% as unchanged drug.

Not applicable since atropine has been used in clinical practice for many years and its effects in man are well known.

Sodium Citrate Dihydrate USP

Citric Acid Monohydrate USP

Sodium Chloride USP

Water for Injection USP

None known.

36 months

Store below 25°C. Protect from light.

The solution is contained in a USP type I glass vial with an elastomeric closure which meets all the relevant USP specifications. The product is available either as 5, 10 or 30ml.

The container is specially designed for use with the IMS Minijet injector.

International Medication Systems (UK) Ltd

208 Bath Road

Slough

Berkshire

SL1 3WE

UK

PL 03265/0013R

Date first granted: 20.03.91

Date renewed: 17 March 1997/16 March 2002

August 2005

POM