atropine sulfate
(a' troe peen)
Parenteral and oral preparations:
Minims (CAN), Sal-Tropine
Ophthalmic solution:
Atropine Sulfate S.O.P., Atropisol, Isopto-Atropine Ophthalmic

Pregnancy Category C

Drug classes
Anticholinergic
Antimuscarinic
Parasympatholytic
Antiparkinsonism drug
Antidote
Diagnostic agent (ophthalmic preparations)
Belladonna alkaloid

Therapeutic actions
Competitively blocks the effects of acetylcholine at muscarinic cholinergic receptors that mediate the effects of parasympathetic postganglionic impulses, depressing salivary and bronchial secretions, dilating the bronchi, inhibiting vagal influences on the heart, relaxing the GI and GU tracts, inhibiting gastric acid secretion (high doses), relaxing the pupil of the eye (mydriatic effect), and preventing accommodation for near vision (cycloplegic effect); also blocks the effects of acetylcholine in the CNS.

Indications
Systemic administration
· Antisialagogue for preanesthetic medication to prevent or reduce respiratory tract secretions
· Treatment of parkinsonism; relieves tremor and rigidity
· Restoration of cardiac rate and arterial pressure during anesthesia when vagal stimulation produced by intra-abdominal traction causes a decrease in pulse rate, lessening the degree of AV block when increased vagal tone is a factor (eg, some cases due to digitalis)
· Relief of bradycardia and syncope due to hyperactive carotid sinus reflex
· Relief of pylorospasm, hypertonicity of the small intestine, and hypermotility of the colon
· Relaxation of the spasm of biliary and ureteral colic and bronchospasm
· Relaxation of the tone of the detrusor muscle of the urinary bladder in the treatment of urinary tract disorders
· Control of crying and laughing episodes in patients with brain lesions
· Treatment of closed head injuries that cause acetylcholine release into CSF, EEG abnormalities, stupor, neurologic signs
· Relaxation of uterine hypertonicity
· Management of peptic ulcer
· Control of rhinorrhea of acute rhinitis or hay fever
· Antidote (with external cardiac massage) for CV collapse from overdose of parasympathomimetic (cholinergic) drugs (choline esters, pilocarpine), or cholinesterase inhibitors (eg, physostigmine, isoflurophate, organophosphorus insecticides)
· Antidote for poisoning by certain species of mushroom (eg, Amanita muscaria)
Ophthalmic preparations
· Diagnostically to produce mydriasis and cycloplegia-pupillary dilation in acute inflammatory conditions of the iris and uveal tract

Contraindications and cautions
· Contraindicated with hypersensitivity to anticholinergic drugs.
· Systemic administration: contraindicated with glaucoma, adhesions between iris and lens, stenosing peptic ulcer, pyloroduodenal obstruction, paralytic ileus, intestinal atony, severe ulcerative colitis, toxic megacolon, symptomatic prostatic hypertrophy, bladder neck obstruction, bronchial asthma, COPD, cardiac arrhythmias, tachycardia, myocardial ischemia, impaired metabolic, liver, or kidney function, myasthenia gravis.
· Use cautiously with Down syndrome, brain damage, spasticity, hypertension, hyperthyroidism, lactation.
· Ophthalmic solution: contraindicated with glaucoma or tendency to glaucoma.

Available forms
Tablets--0.4 mg; injection--0.05, 0.1, 0.3, 0.4, 0.5, 0.8, 1 mg/mL; ophthalmic ointment--1%; ophthalmic solution--0.5%, 1%, 2%

Dosages
ADULTS
· Systemic administration: 0.4–0.6 mg PO, IM, SC, IV.
· Hypotonic radiography: 1 mg IM.
· Surgery: 0.5 mg (0.4–0.6 mg) IM (or SC, IV) prior to induction of anesthesia; during surgery, give IV; reduce dose to < 0.4 mg with cyclopropane anesthesia.
· Bradyarrhythmias: 0.4–1 mg (up to 2 mg) IV every 1–2 hr as needed.
· Antidote: For poisoning due to cholinesterase inhibitor insecticides, give large doses of at least 2–3 mg parenterally, and repeat until signs of atropine intoxication appear; for rapid type of mushroom poisoning, give in doses sufficient to control parasympathetic signs before coma and CV collapse intervene.
Ophthalmic solution
· For refraction: Instill 1–2 drops into eye(s) 1 hr before refracting.
· For uveitis: Instill 1–2 drops into eye(s) qid.
PEDIATRIC PATIENTS
Systemic administration
Refer to the following chart:
Weight
Dose (mg)
7–16 lb (3.2–7.3 kg)
0.1
16–24 lb (7.3–10.9 kg)
0.15
24–40 lb (10.9–18.1 kg)
0.2
40–65 lb (18.1–29.5 kg)
0.3
65–90 lb (29.5–40.8 kg)
0.4
> 90 lb (> 40.8 kg)
0.4–0.6

· Surgery: 0.1 mg (newborn) to 0.6 mg (12 yr) injected SC 30 min before surgery.
GERIATRIC PATIENTS
More likely to cause serious adverse reactions, especially CNS reactions, in elderly patients; use with caution.

Pharmacokinetics
Route
Onset
Peak
Duration
IM
10–15 min
30 min
4 hr
IV
Immediate
2–4 min
4 hr
SC
Varies
1–2 hr
4 hr
Topical
5–10 min
30–40 min
7–14 days


Metabolism: Hepatic; T1/2: 2.5 hr
Distribution: Crosses placenta; passes into breast milk
Excretion: Urine

IV facts
Preparation: Give undiluted or dilute in 10 mL sterile water.
Infusion: Give direct IV; administer 1 mg or less over 1 min.

Adverse effects
Systemic administration
· CNS: Blurred vision, mydriasis, cycloplegia, photophobia, increased intraocular pressure, headache, flushing, nervousness, weakness, dizziness, insomnia, mental confusion or excitement (after even small doses in the elderly), nasal congestion
· CV: Palpitations, bradycardia (low doses), tachycardia (higher doses)
· GI: Dry mouth, altered taste perception, nausea, vomiting, dysphagia, heartburn, constipation, bloated feeling, paralytic ileus, gastroesophageal reflux
· GU: Urinary hesitancy and retention; impotence
· Other: Decreased sweating and predisposition to heat prostration, suppression of lactation
Ophthalmic preparations
· Local: Transient stinging
· Systemic: Systemic adverse effects, depending on amount absorbed

Interactions
Drug-drug
· Increased anticholinergic effects with other drugs that have anticholinergic activity: certain antihistamines, certain antiparkinsonian drugs, TCAs, MAO inhibitors
· Decreased antipsychotic effectiveness of haloperidol with atropine
· Decreased effectiveness of phenothiazines, but increased incidence of paralytic ileus

Nursing considerations
Assessment
· History: Hypersensitivity to anticholinergic drugs; glaucoma; adhesions between iris and lens; stenosing peptic ulcer, pyloroduodenal obstruction, paralytic ileus, intestinal atony, severe ulcerative colitis, toxic megacolon, symptomatic prostatic hypertrophy, bladder neck obstruction, bronchial asthma, COPD, cardiac arrhythmias, myocardial ischemia, impaired metabolic, liver, or kidney function, myasthenia gravis, Down syndrome, brain damage, spasticity, hypertension, hyperthyroidism, lactation
· Physical: Skin color, lesions, texture; T; orientation, reflexes, bilateral grip strength; affect; ophthalmic exam; P, BP; R, adventitious sounds; bowel sounds, normal GI output; normal urinary output, prostate palpation; liver and kidney function tests, ECG

Interventions
· Ensure adequate hydration; provide environmental control (temperature) to prevent hyperpyrexia.
· Have patient void before taking medication if urinary retention is a problem.

Teaching points
· When used preoperatively or in other acute situations, incorporate teaching about the drug with teaching about the procedure; the ophthalmic solution is used mainly acutely and will not be self-administered by the patient; the following apply to oral medication for outpatients:
· Take as prescribed, 30 min before meals; avoid excessive dosage.
· Avoid hot environments; you will be heat intolerant, and dangerous reactions may occur.
· These side effects may occur: dizziness, confusion (use caution driving or performing hazardous tasks); constipation (ensure adequate fluid intake, proper diet); dry mouth (sugarless lozenges, frequent mouth care may help; may be transient); blurred vision, sensitivity to light (reversible; avoid tasks that require acute vision; wear sunglasses in bright light); impotence (reversible); difficulty in urination (empty the bladder prior to taking drug).
· Report rash; flushing; eye pain; difficulty breathing; tremors, loss of coordination; irregular heartbeat, palpitations; headache; abdominal distention; hallucinations; severe or persistent dry mouth; difficulty swallowing; difficulty in urination; constipation; sensitivity to light.

Adverse effects in Italic are most common; those in Bold are life-threatening.