Dosing and uses of AtroPen (atropine IV/IM)
Adult dosage forms and strengths
intramuscular device
- 0.25mg/0.3mL
- 0.5mg/0.7mL
- 1mg/0.7mL
- 2mg/0.7mL
injectable solution
- 0.05mg/mL
- 0.1mg/mL
- 0.4mg/mL
- 0.8mg/mL
- 1mg/mL
Anesthesia Premedication
0.4-0.6 mg IV/IM/SC 30-60 minutes before anesthesia; repeat q4-6hr PRn
Sinus Bradycardia (ACLS)
0.5-1 mg or 0.04 mg/kg IV q5min, no more than 3 mg
ET: Some experts suggest 2-3 times IV dose diluted in3- 5 mL sterile water for injection/NS (sterile water for injection may facilitate absorption better than NS, but may produce more negative effect on arterial oxygen pressure)
Bronchospasm
0.025 mg/kg in 2.5 mL NS q6-8hr via nebulizer; no more than 2.5 mg/dose
Asystole/Pulseless Electrical Activity (ACLS)
1 mg IV q3-5min PRN if asystole persist up to 0.04 mg/kg
Cholinesterase Inhibitors (Organophosphates, Carbamates)
AtroPen: 2 mg/dose Im
Mild symptoms: 1 AtroPen dose
If severe symptoms develop (eg, strange or confused behavior, wheezing, sialorrhea, muscle fasciculations, involuntary urination/defecation, convulsion, unconsciousness) give 2 additional AtroPen injections in rapid succession 10 minutes after initial dose
Initial severe symptoms: Give 3 AtroPen doses in rapid succession
Pediatric dosage forms and strengths
intramuscular device
- 0.25mg/0.3mL
- 0.5mg/0.7mL
- 1mg/0.7mL
- 2mg/0.7mL
injectable solution
- 0.05mg/mL
- 0.1mg/mL
- 0.4mg/mL
- 0.8mg/mL
- 1mg/mL
Anesthesia Premedication
<5 kg: 0.02 mg/kg/dose 30-60 minutes preop; then q4-6hr PRn
>5 kg: 0.01-0.02 mg/kg IV/IM/SC; no more than 0.4 mg
Sinus Bradycardia
0.02 mg/kg IV/IO q5min for 2-3 doses PRN; single dose no less than: 0.1 no more than 0.5 mg (children), 1 mg (adolescents)
Total: No more than: 1 mg (children), 2 mg (adolescents)
ET: Some experts suggest 0.03 mg/kg, diluted in Ns
Bronchospasm
0.025-0.05 mg/kg in 2.5 mL NS q6-8hr via nebulizer; no more than 2.5 mg/dose
Organophosphate or Carbamate Poisoning
IV: 0.03-0.05 mg/kg IV/IM/IO/ET q10-20min PRN to effect; then q1-4hr for at least 24 hours
IM (AtroPen):
Mild symptoms: 1 AtroPen dose (see specific dose for weight below)
If severe symptoms develop (eg, strange or confused behavior, wheezing, sialorrhea, muscle fasciculations, involuntary urination/defecation, convulsion, unconsciousness) give 2 additional AtroPen injections in rapid succession 10 minutes after initial dose
Severe symptoms
- 3 AtroPen doses in rapid succession
- >41 kg: 2 mg/dose IM
- 18-41 kg: 1 mg/dose IM
- 6.8-18 kg: 0.5 mg/dose IM
- <6.8 kg: AtroPen formulation not recommended; administer atropine 0.05 mg/kg bradyarrhythmias
AtroPen (atropine IV/IM) adverse (side) effects
Frequency not defined
Anticholinergic symptoms (mydriasis, hyperthermia, tachycardia, cardiac arrhythmia, delayed gastric emptying)
Ataxia
Fever
Headache
Insomnia
Dry mouth
Anhidrosis
Urticaria
Urinary hesitancy
Dry skin
Blurred vision
Cycloplegia
Photophobia
Anhidrosis
Palpitation
Dyspnea
Paralytic ileus
Pulmonary edema
Nasal dryness
Xerophthalmia
Constipation
May increase IOP in predisposed patients
May cause CNS disturbances (especially in pediatric patients)
Warnings
Contraindications
No absolute contraindications for ACLs
- Ineffective in hypothermic bradycardia
Narrow-angle glaucoma, tachycardia, asthma, GI obstruction, severe ulcerative colitis, toxic megacolon, bladder outlet obstruction
Cautions
Caution in hepatic/renal impairment, BPH, CHF
Not for effective treatment of type II second or third-degree AV block with or without a new wide QRS complex
Use caution in autonomic neuropathy, myocardial ischemia, heart failure, paralytic ileus, hepatic impairment, hiatal hernia associated with reflux esophagitis, hyperthyroidism, myasthenia gravis, and renal impairment
Heat prostration can occur in high environmental temperature
Psychosis reported in sensitive individuals and with excessive doses
When recurrent use of atropine is essential in patients with coronary artery disease, total dose should be restricted to 2 to 3 mg (maximum 0.03 to 0.04 mg/kg) to avoid detrimental effects of atropine-induced tachycardia on myocardial oxygen demand
May precipitate acute glaucoma
May convert partial organic pyloric stenosis into complete obstruction
May lead to complete urinary retention in patients with prostatic hypertrophy
May cause inspissation of bronchial secretions and formation of viscid plugs in patients with chronic lung disease
Pregnancy and lactation
Pregnancy category: C
Lactation: Trace amounts enter breast milk; use with caution (AAP Committee states "compatible with nursing")
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of AtroPen (atropine IV/IM)
Mechanism of action
Competitively inhibits action of ACh on autonomic effectors innervated by postganglionic nerves; reverses muscarinic effects of cholinergic poisoning caused by agents with cholinesterase inhibitor activity by acting as a competitive antagonist of acetylcholine ast muscarinic receptors; blocks action of acetylcholiine at parsympathetic sites in secretory glands, and CNS; inhibits salivation, tracheobronchial secretions, bradycardia, hypotension
Antimuscarinic agent
Pharmacokinetics
Half-Life: 2-3 hr (>2 years and adults); 7 hr (<2 years); 10 hr (65-75 years)
Peak Plasma Time: 3 min (IM)
Onset: Rapid (IV/IM)
Bronchodilation: Within 15 min; max within 15 min-1.5 hr (oral inhalation)
Distribution: Throughout the body; crosses blood brain barrier
Absorption: Principally from the upper small intestine
Metabolites: Tropic acid, tropine, & possibly esters of tropic acid and glucuronide conjugates
Metabolism: Liver via enzymatic hydrolysis
Excretion: Urine (30-50%); small amounts may also be eliminated in expired air as carbon dioxide & in feces
Administration
IV Incompatibilities
Additive: floxacillin
Syringe: cimetidine w/ pentobarbitaL
Y-site: thiopentaL
Not spec: ampicillin, diazepam, epinephrine, norepinephrine
IV Compatibilities
Additive: dobutamine, furosemide, meropenem, netilmicin, Na bicarb, verapamiL
Syringe: (partial list) cimetidine, fentanyl, glycopyrrolate, heparin, hydroxyzine, meperidine, morphine, pentobarbitaL
Y-site: abciximab, amiodarone, argatroban, etomidate, famotidine, fenoldopam, fentanyl, heparin, hydrocortisone, hydromorphone, inamrinone, meropenem, methadone, morphine, nafcillin, KCl, propofol, sufentanil, tirofiban, vit B/C
IV Administration
SC, IM, IV
Give into large vein or IV tubing over 1-2 min
