Each mL contains: Atropine Sulfate 1 mg.
Pharmacology: Pharmacodynamics: Antimuscarinic drugs are competitive inhibitors of the actions of acetylcholine at the muscarinic receptors of autonomic effector sites innervated by parasympathetic (cholinergic postganglionic) nerves, as well as being inhibitors of the action of acetylcholine on smooth muscle lacking cholinergic innervations. They have also been described as parasympatholytic, atropinic, atropine-like, and as anticholinergic, although the latter term should encompass compounds that also have antinicotinic actions. Atropine is a tertiary amine antimuscarinic alkaloid with both central and peripheral actions. It first stimulates then depresses the CNS and has antispasmodic actions on smooth muscle and reduces secretions, especially salivary and bronchial secretions; it also reduces perspiration, but has little effect on biliary or pancreatic secretion. Atropine depresses the vagus and thereby increases the heart rate.
Pharmacokinetics: Atropine is readily absorbed from the gastrointestinal tract; it is also absorbed from mucous membranes, the eyes, and to some extent through intact skin. It is rapidly cleared from the blood and is distributed throughout the body. It crosses the blood-brain barrier. It is incompletely metabolized in the liver and is excreted in the urine as unchanged drug and metabolites. A half-life of about 4 hours has been reported. Atropine crosses the placenta and traces appear in breast milk.
Atropine is used for a variety of purposes, including: in anesthetic practice as a premedicant and to counteract the muscarinic effects of anticholinesterases such as neostigmine and other parasympathomimetics; as an antispasmodic in gastrointestinal disorders; as an adjunct to opioid analgesics for the symptomatic relief of biliary or renal colic; to treat bradycardia; to treat or prevent bronchospasm; and in the treatment of poisoning with mushrooms that contain muscarine and in organophosphorus pesticide poisoning.
Atropine as a premedicant before general anesthesia is given subcutaneously or intramuscularly at a dose of 300 to 600 mcg of atropine sulfate. It is usually administered 30 to 60 minutes before anesthesia. Alternatively 300 to 600 mcg of atropine sulfate may be given intravenously immediately before induction of anesthesia. Atropine sulfate may also be given in combination with up to 10 mg morphine sulfate by subcutaneous or intramuscular injection about an hour before anesthesia. Suitable pediatric premedication doses of atropine sulfate are: 100 mcg subcutaneously or intramuscularly for children weighing up to 3 kg; 200 mcg for children weighing 7 to 9 kg; 300 mcg for children weighing 12 to 16 kg; and children weighing over 20 kg may be given the adult dose. To counteract the muscarinic effects of anticholinesterases when they are used to reverse the effects of competitive muscle relaxants, adults are given atropine sulfate 0.6 to 1.2 mg by intravenous injection before or with the anticholinesterases. Neonates and infants may be given a dose of 20 mcg per kg body weight. Recommended doses of atropine sulfate in asystole and electromechanical dissociation, of 1 mg intravenously, repeated every 3 to 5 minutes to a total of 0.04 mg per kg body weight. In bradycardia, atropine is given in doses of 0.5 to 1 mg intravenously repeated every 3 to 5 minutes to a total dose of 0.04 mg per kg body weight. In the treatment of poisoning with organophosphorus pesticides or chemical warfare nerve gases atropine sulfate may be given to adults in an initial dose of 2 mg or more intramuscularly or intravenously every 10 to 30 minutes until muscarinic effects disappear or signs of atropine toxicity are seen. In severe cases injections have been given as often as every 5 minutes in some centers. In moderate to severe poisoning a state of atropinisation is usually maintained for at least 2 days and continued for as long as symptoms are evident. The use of atropine in poisoning or overdosage with other compounds having muscarinic actions is similar to that for organophosphorus pesticides but the duration of treatment necessary is usually shorter. An initial dose of 0.5 to 1 mg given subcutaneously or intravenously and repeated every 2 hours may be adequate for overdosage with cholinomimetics such as bethanechol. Or as prescribed by a physician.
Contraindicated in patients with prostate enlargement, in whom it may lead to urinary retention, and in those with paralytic ileus or pyloric stenosis. Atropine should not be given to patients with angle-closure glaucoma or with a narrow angle between the iris and the cornea; patients with myasthenia gravis except to reduce adverse muscarinic effects of anticholinesterases and patients, especially children, when the ambient temperature is high due to the risk of provoking hyperthermia.
Atropine needs to be used with caution in children and the elderly, who may be more susceptible to its adverse effects. In patients with ulcerative colitis its use may lead to ileus or megacolon, and its effects on the lower esophageal sphincter may exacerbate reflux. Caution is generally advisable in any patient with diarrhea; patients with fever due to the risk of hyperthermia and in patients whom conditions are characterized by tachycardia such as thyrotoxicosis, heart failure, and in cardiac surgery, where it may further accelerate the heart rate. Reduced bronchial secretion caused by systemic administration of atropine may be associated with the formation of mucous plugs. In the treatment of Parkinsonism, increases in dosage and transfer to other forms of treatment should be gradual and antimuscarinic should not be withdrawn abruptly. Minor reactions may be controlled by reducing the dose until tolerance has developed. Persons with Down's Syndrome appear to have an increased susceptibility to some of the actions of atropine, whereas those with albinism may have a reduced susceptibility. Care is required in patients with acute myocardial infarction, as ischemia and infarction may be made worse, and in patients with hypertension. Atropine may cause confusion, especially in the elderly. Systemic administration of atropine may also cause blurred vision, dizziness, and other effects that may impair a patient's ability to perform skilled tasks such as driving.
The effects of atropine are dose-related and are usually reversible when therapy is discontinued. The peripheral side effects are a consequence of their inhibitory effect on muscarinic receptors within the autonomic nervous system. At therapeutic doses, adverse effects include dryness of the mouth with difficulty in swallowing and talking, thirst, reduced bronchial secretions, dilatations of the pupils or mydriasis with loss of accommodation or cycloplegia and photophobia, flushing and dryness of the skin, transient bradycardia followed by tachycardia, with palpitations and arrhythmias, and difficulty in micturition, as well as reduction in the tone and motility of the gastrointestinal tract leading to constipation. Some of the central side effects of atropine seen at toxic doses may also occur at therapeutic doses. Hypersensitivity to atropine is common and may occur as conjunctivitis or a skin rash. Atropine can cause hyperthermia as a result of inhibition of sweating. This may be attenuated by atropine's ability to dilate cutaneous blood vessels.
Treatment of Adverse Effects.
Supportive therapy should be given as required. Physostigmine has been tried for antimuscarinic poisoning but such use can be hazardous and is not generally recommended. Diazepam may be given to control marked excitement and convulsions; phenothiazines should not be given as they may exacerbate antimuscarinic effects. Antiarrhythmics are not recommended if arrhythmias develop; hypoxia and acidosis should be corrected and sodium bicarbonate may be given even if acidosis is not present.
The effects of atropine may be enhanced by the concomitant administration of other drugs with antimuscarinic properties, such as amantadine, some antihistamines, phenothiazine antipsychotics, and tricyclic antidepressants. Inhibition of drug metabolizing enzymes by MAOIs may possibly enhance the effects of antimuscarinics. The reduction in gastric motility caused by antimuscarinics may affect the absorption of other drugs. Antimuscarinics and parasympathomimetics may counteract each others effects.
Store at temperatures not exceeding 30°C.
A03BA01 - atropine ; Belongs to the class of belladonna alkaloids, tertiary amines. Used in the treatment of functional gastrointestinal disorders.
Atropan soln for inj 1 mg/mL
1 mL x 10 × 1's