ATROPINE SULFATE Flashcards
Generic Name?
Atropine Sulfate
Trade Name?
None
Class?
Anticholinergic agent Antidote Antispasmodic agent Antiarrhythmic Antimuscarinic
Mechanism of Action?
Pharmacological: Blocks the action of acetylcholine as a competitive antagonist at muscarinic receptor sites in smooth muscle, secretory glands, & CNS. Blocks parasympathetic response & allowing sympathetic response to take over, resulting in increase in cardiac output & drying secretions. Atropine reverses muscarinic effects of cholinergic poisoning by primarily reversing bronchorrhea & bronchoconstriction. At high doses, atropine may have an effect on nicotinic receptors responsible for restlessness, hallucinations, disorientation, & delirium.
Clinical:
CV: Increased heart rate (positive chronotropic effect); increased conduction velocity; increased force of contraction (slight), increased cardiac output.
RESP: Decreased mucus production; increased bronchial smooth muscle relaxation (bronchodilation)
GI: Decreased GI secretion and motility.
GU: Decreased urinary bladder tone.
MISC: Mydriasis (Pupillary dilation); decreased sweat production.
Indications?
Symptomatic bradycardia (sinus, junctional, & AV blocks causing significant hypotension, ventricular ectopy, chest pain, altered level of consciousness, etc.) Monitored patient only. Acetylcholinesterase inhibitor poisoning (organophosphate, carbamate cholinergic poisoning)
Contraindications?
Hypersensitivity to atropine or any component of the formulation- Belladonna alkaloid allergy.
Glaucoma, acute narrow angle (relative contraindication for
Patient with symptomatic bradycardia), adhesions between iris and lens.
Obstructive GI disease, paralytic ileus, intestinal atony of elderly or debilitated patient, severe ulcerative colitis, or toxic megacolon complicating ulcerative colitis.
Hepatic disease
Tachycardia
Renal disease, obstuctive uropathy
Myasthenia gravis (unless used to treat side effects of acetylcholinesterase inhibitor)
Asthma
Thyrotoxicosis
Mobitz type 2 block
3rd degree heart block
Side Effects?
Major: Tachydysrhythmias, flushing, ventricular irritability; exacerbation/initiation of angina, acute narrow angle glaucoma, blurred vision, mydriasis, agitation to delirium, bloating, constipation, decreased gastric emptying.
Minor: Dry mouth/mucous membranes, loss of taste, nausea, vomiting, urinary retention, neuromuscular weakness, decreased sweating/increased body temp
Pregnancy:
Risk category C: Animal reproduction studies not been conducted. Atropine has been found to cross human placenta. Trace amounts of atropine can enter breast milk, use caution. Anticholinergic agents may suppress lactation.
Drug Interactions?
Incompatibilities:
Y-site incompatible with thiopental
Syringe incompatible with cimetidine, pentobarbital (variable)
Admixture incompatible with floxacillin, metaraminol, methohexital, norepinephrine
Sodium bicarbonate (relative)
Drug Interactions:
Atropine may increase levels/effects of: anticholinergics, cannabinoids, & potassium chloride.
Atropine may decrease the levels/effects of: phenothiazines, acetylcholinesterase inhibitors (central), & secretin
Concurrent use of atropine with psychotropics may result in
Additive anticholiergic side effects (dry mouth, blurred vision, constipation)
Pramlintide may increase levels/effects of atropine
Acetylcholinesterase inhibitors (central) may decrease the levels/effects of atropine
Adult Dose?
Special Instructions:
IV/IO- administer undiluted by rapid IV injection; slow injection may result in paradoxical bradycardia. Doses <0.5 mg may increase vagal tone resulting in paradoxical bradycardia.
IM- Atropen should be administered to outer thigh. May be given through clothing as long as pockets at injection site are clear. Hold autoinjector in place for 10 seconds following injection; massage injection site.
Symptomatic Bradycardia:
IV/IO- 0.5 mg every 5 minutes. Do NOT exceed a total dose of 3 mg or 0.04 mg/kg if symptoms profound.
- consider atropine before pacing in mildly symptomatic patients, but do not delay pacing in unstable patients, particularly those in high-degree AV block.
- Do not rely on atropine in Mobitz type 2 2nd or 3rd degree AV block or in patients with 3rd degree AV block with a new wide QRS complex. Hemodynamically unstable & clinically deteriorating patients require immediate pacing.
Organophosphate or carbamate poisoning:
IV/IO- initially 1-5 mg. Doses should be doubled every 5 minutes until signs of muscarinic excess abate (clearing of bronchial secretions, bronchospasm, & adequate oxygenation)
IV infusion- 0.5-1 mg/hour or 10-20% of loading dose/hour
IM- (Atropen) mild symptoms: Administer 2 mg as soon as exposure is known or suspected. If severe symptoms develop after 1st dose, 2 additional doses should be repeated every 10 minutes, not to exceed more than 3 doses. Severe symptoms: Immediately administer three 2 mg doses.
Pediatric Dose?
Symptomatic Bradycardia:
IV/IO- 0.02 mg/kg (minimum 0.01 mg), repeat at 5 minute intervals to max total dose of 1 mg in children & 2 mg in adolescents.
Maximum single doses: Child 0.5 mg; Adolescent 1 mg.
-For bradycardia neonates, reserve use for those unresponsive to improved O2 & epinephrine.
Organophosphate or carbamate cholinergic poisoning:
IV/IO- 0.03-0.05 mg/kg every 10-20 minutes until cholinergic symptoms minimize, than every 1 to 4 hours for at least 24 hours.
IM- Administer dose as listed below as soon as exposure is known or suspected. If severe symptoms develop after 1st dose, 2 additional doses should be repeated in 10 minutes. Do NOT administer more than 3 doses. For severe symptoms, immediately administer 3 doses as follows:
- 90lbs); 2 mg/dose
Onset?
Onset of Action: Rapid, 1 minute
Peak Effects: IV- 2-5 minutes; IM 30 minutes
Duration of Action: Half-life 2-3 hrs; Terminal half-life 12.5 hours.
- Intravenous, intraosseous, intrathecal, or intramuscular (using Atropen); ok for endotracheal if necessary.
Special Notes?
- Administering too small doses or too slowly may result in paradoxical bradycardia
- may accumulate with multiple inhalation admin, particularly elderly
- signs/symptoms of cholinergic/organophosphate poisoning; excess salivation, lacrimation, urination, defecation (SLUD), bradycardia, coma.
- signs/symptoms of poisoning of atropine-like drugs: dry mouth, thirst, hot, dry, flushed skin, fever, palpitations, restlessness, excitement, delirium.
Hint: Painful Glaucoma- acute narrow angle glaucoma - Atropine utilized when no pacer available for 2nd degree type 2 & 3rd degree heart blocks.
- Atropine affects pupil response; fixed pupils
