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Prophylaxis of Vasovagal Reaction With Atrohist Plus
Arch Ophthalmol. 2001;119:1079-1080.
Vasovagal reactions (VVRs) can present a treatment dilemma for medical
professionals, and fear of causing such reactions can prevent ophthalmologists
from performing necessary examinations. Atenolol, midodrine hydrochloride,
paroxetine, fludrocortisone acetate, as well as salt and fluid intake have
demonstrated efficacy in treating the disorder.1
Other vasoconstrictors and selective serotonin reuptake inhibitors are being
studied, but to our knowledge, there are no medications to prevent isolated
incidents of VVR with known triggers.2 We
describe 2 patients who experienced VVRs on applanation tonometry or instillation
of dilating drops. Subsequent reactions were prevented with oral Atrohist
Plus (a combination of phenylephrine hydrochloride, phenylpropanolamine hydrochloride,
chlorpheniramine maleate, hyoscyamine sulfate, atropine sulfate, and scopolamine
hydrobromide; Vintage Pharmaceuticals Inc, Charlotte, NC) administered 1 hour
prior to examination.
Report of Cases
Case 1
A 41-year-old healthy man with an ocular history of myopia and a family
history of glaucoma was seen for complaints of decreased visual acuity for
several months. After instillation of a fluorescein sodium–benoxinate
hydrochloride solution, the applanation tonometry demonstrated the intraocular
pressure (IOP) of 21 mm Hg OU, and immediately after tonometry, the patient
fainted. Owing to lightheadedness, he refused additional drops for dilation.
The undilated fundus examination revealed a cup-disc ratio of 0.50 U. The
patient was followed as a glaucoma suspect, and after each IOP measurement,
he felt faint, sweaty, or lightheaded. On one occasion, he experienced a severe
VVR, became lightheaded, tremulous, diaphoretic, and fainted. Blood pressure
and pulse were measured immediately following this presumed VVR and were found
to be normal, 134/84 mm Hg and 74 bpm, respectively. No formal testing for
VVR was performed.
Repeated IOP examinations were indicated, but additional tonometry measurements
incurred a high risk of another syncopal episode. Since there are no oral
medications identified in the literature to prevent isolated incidents of
VVR, intravenous atropine was suggested by a cardiologist. As an alternative
to the intravenous medication, Atrohist Plus was selected, and 1 tablet was
administered to the patient 1 hour prior to tonometry measurement. Applanation
tonometry was performed, and the patient did not experience any symptoms of
VVR. One tablet of oral Atrohist Plus was administered 1 hour prior to his
next 3 office visits, and no symptoms of VVR were reported.
Case 2
A 21-year-old healthy man with no medical problems was known to experience
a VVR and faint after the instillation of dilating drops. The patient had
an ocular history of myopia and contact lens wear and was seen for a comprehensive
examination and laser in situ keratomileusis consultation. One tablet of Atrohist
Plus was administered approximately 1 hour prior to the eye examination. A
complete eye examination was performed, including applanation tonometry followed
by instillation of dilating drops (1% tropicamide and 2.5% phenylephrine).
No symptoms of VVR were reported.
Comment
Predictable VVRs and fainting during tonometry or instillation of eye
medications are uncommon occurrences but may force the ophthalmologist to
choose between a comprehensive eye examination and an adverse event. The use
of the oral medication, Atrohist Plus, can be a useful tool in the prevention
of VVR when the ophthalmologist is aware of the precipitating factor. The
primary indication for use is for relief from irritation of sinus, nasal,
and upper respiratory tissues owing to its vasoconstrictive properties and
subsequent drying of the mucosa. The drug is contraindicated in patients receiving
monoamine oxidase inhibitors, patients with asthma, patients younger than
12 years, women who may be pregnant, or patients with known hypersensitivity
to antihistamines or sympathomimetics. In addition, acute angle-closure glaucoma
may be precipitated by the dilating effects of this oral medication; therefore,
narrow angles should be ruled out before its administration.3
Atrohist Plus presumably prevents VVRs through the anticholinergic effects
of atropine, hyoscyamine, and scopolamine and the adrenergic effects of phenylephrine
and phenylpropanolamine. The anticholinergics act by blocking acetylcholine
at the muscarinic receptors in smooth muscle, cardiac muscle, and sinoatrial
and atrioventricular nodes as well as in exocrine glands, resulting in increased
heart rate and blood pressure and decreased heart block. Phenylephrine acts
primarily on  -1 adrenergic receptors in arterial smooth muscle to cause
vasoconstriction, while phenylpropanolamine acts on both -1 and 2 and  -1
receptors to cause vasoconstriction as well as increased heart rate, contractility,
and cardiac output. The combination of medications most likely acts by preventing
the bradycardia and hypotension associated with VVR.4
AUTHOR INFORMATION
Michael R. Koop, MD;
Norbert Becker, MD
Chicago, Ill
Corresponding author: Norbert Becker, MD, Cook County Hospital, 1835
W Harrison, Chicago, IL 60612(e-mail: www.genevaeye.com).
REFERENCES
1. Calkins H. Pharmacologic approaches to therapy for vasovagal syncope. Am J Cardiol. 1999;84:20Q-25Q.
2. White CM, Tsikouris JP. A review of pathophysiology and therapy of patients with vasovagal
syncope. Pharmacotherapy. 2000;20:158-165.
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3. Atrohist Plus [package insert]. Charlotte, NC: Vintage Pharmaceuticals; 2000.
4. Drug Information for the Health Care Professional. Vol 1. Greenwood Village, Colo: Micromedex; 2001.
SECTION EDITOR: W. RICHARD GREEN, MD
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