Homatropine (Ophthalmic)


VA CLASSIFICATION
Primary: OP600

Commonly used brand name(s): AK-Homatropine; I-Homatrine; Isopto Homatropine; Minims Homatropine; Spectro-Homatropine.

Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).



Category:


Cycloplegic—

mydriatic—

Indications
{60}
Accepted

Refraction, cycloplegic {08} {29} —Homatropine is indicated for measurement of refractive errors. {60}

Uveitis (treatment) {08} {29} —Homatropine is indicated for pupil dilation {91} and ciliary muscle relaxation, which are desirable in acute {43} inflammatory conditions of the uveal tract.

Mydriasis, postoperative or {08}
Mydriasis, preoperative {08} — Homatropine may be indicated to produce mydriasis in some preoperative and postoperative conditions.

Lens opacities, axial {08} {60} —Homatropine is indicated as an optical aid in some cases of axial lens opacities.


Pharmacology/Pharmacokinetics

Mechanism of action/Effect:

Homatropine (a belladonna alkaloid) is an anticholinergic agent that blocks the responses of the sphincter muscle of the iris and the accommodative muscle of the ciliary body to stimulation by acetylcholine. {08} Dilation of the pupil (mydriasis) and paralysis of accommodation (cycloplegia) result. {08}

Duration of action:

Moderately long-acting {08} cycloplegic and mydriatic.

Has a shorter duration of action than atropine.

Residual cycloplegia and mydriasis may persist for 24 to 72 hours following instillation of medication.


Precautions to Consider

Cross-sensitivity and/or related problems

Patients sensitive to any of the other belladonna alkaloids may be sensitive to homatropine also.

Carcinogenicity

No long-term studies in animals have been done. {08}

Pregnancy/Reproduction

Pregnancy—
Studies have not been done in humans; however, ophthalmic homatropine may be systemically absorbed. {08}

Studies have not been done in animals. {08}

FDA Pregnancy Category C. {08}

Breast-feeding

It is not known whether homatropine is distributed into breast milk. {08} Problems in humans have not been documented; however, ophthalmic homatropine may be systemically absorbed.

Pediatrics

An increased susceptibility to homatropine and similar drugs (such as atropine) has been reported in infants {59} and young children {59} and in children with blond hair, {59} blue eyes, {59} Down's syndrome, {59} spastic paralysis, {59} or brain damage. {59}Only homatropine 2% should be used in these and other pediatric patients. {08}


Geriatrics

{08}{60}
Geriatric patients are more susceptible to the effects of homatropine {59} and similar drugs (such as atropine), {59} thus increasing the potential for systemic side effects.

Drug interactions and/or related problems
The following drug interactions and/or related problems have been selected on the basis of their potential clinical significance (possible mechanism in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):


Note: Combinations containing any of the following medications, depending on the amount present, may also interact with this medication.

Anticholinergics or medications with anticholinergic activity, other (See Appendix II )    (if significant systemic absorption of ophthalmic homatropine occurs, concurrent use of other anticholinergics or medications with anticholinergic activity may result in potentiated anticholinergic effects)


Antiglaucoma agents, cholinergic, long-acting, ophthalmic {78} {79} {80}    (concurrent use with homatropine may antagonize the antiglaucoma and miotic actions of ophthalmic long-acting cholinergic antiglaucoma agents, such as demecarium, echothiophate, and isoflurophate; concurrent use with homatropine may also antagonize the antiaccommodative convergence effects of these medications when they are used for the treatment of strabismus {91})


Antimyasthenics or {85}
Potassium citrate {84} or
Potassium supplements {83}    (if significant systemic absorption of ophthalmic homatropine occurs, concurrent use may increase the chance of toxicity and/or side effects of these systemic medications because of the anticholinergic-induced slowing of gastrointestinal motility)


Carbachol or {91}
Physostigmine or {91}
Pilocarpine {91}    (concurrent use with homatropine may interfere with the antiglaucoma action of carbachol, physostigmine, or pilocarpine. Also, concurrent use counteracts the mydriatic effect of homatropine; {91} this counteraction may be used to therapeutic advantage)


CNS depression–producing medications (See Appendix II )    (if significant systemic absorption of ophthalmic homatropine occurs, concurrent use of medications having CNS effects, such as antiemetic agents, phenothiazines, or barbiturates, may result in opisthotonos, convulsions, coma, and extrapyramidal symptoms {82})


Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Except under special circumstances, this medication should not be used when the following medical problems exist:
» Glaucoma, primary, or predisposition to angle closure {08}
» Sensitivity to homatropine {08}
Risk-benefit should be considered when the following medical problems exist
Brain damage, in children {59}
Down"s syndrome (mongolism), in children and adults {59}
Keratoconus    (homatropine may produce fixed dilated pupil {08})


Spastic paralysis, in children {59}
Synechiae between the iris and lens {91}


Side/Adverse Effects

Note: An increased susceptibility to homatropine and similar drugs (such as atropine) has been reported in infants, {59} young children, {59} children with blond hair {59} or blue eyes, {59} adults and children with Down's syndrome, {59} children with brain damage {59} or spastic paralysis, {59} and the elderly. {59} This susceptibility increases the potential for systemic side effects.
Prolonged use of homatropine may produce local irritation, resulting in follicular conjunctivitis, vascular congestion, edema, exudate, contact dermatitis, or an eczematoid dermatitis. {08}

The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Symptoms of systemic absorption
    
Clumsiness or unsteadiness
    
confusion or unusual behavior {08}
    
dryness of skin {60}
    
fever
    
flushing or redness of face
    
hallucinations (seeing, hearing, or feeling things that are not there)
    
skin rash
    
slurred speech
    
swollen stomach in infants
    
tachycardia (fast or irregular heartbeat)
    
unusual drowsiness
    
tiredness or weakness
    
xerostomia {08} (thirst or dryness of mouth)



Those indicating need for medical attention only if they continue or are bothersome
    
Blurred vision {08}
    
eye irritation not present before therapy {08}
    
increased sensitivity of eyes to light {08}
    
swelling of the eyelids
    
transient burning or stinging of the eyes{08}




Overdose
For specific information on the agents used in the management of ophthalmic homatropine overdose, see:
   • Atropine in Anticholinergics/Antispasmodics (Systemic) monograph;
   • Diazepam in Benzodiazepines (Systemic) monograph; and/or
   • Physostigmine (Systemic) monograph.
For more information on the management of overdose or unintentional ingestion, contact a poison control center (see Poison Control Center Listing ).

Treatment of overdose
For accidental ingestion, emesis or gastric lavage with 4% tannic acid solution is recommended. {43}

For systemic effects, 0.2 to 1 mg (0.2 mg in children) physostigmine should be administered intravenously, as a dilution containing 1 mg in 5 mL of normal saline. {43} The solution should be injected over a period of not less than 2 minutes. {43} Dosage may be repeated every 5 minutes up to a total dose of 2 mg in children and 6 mg in adults in each 30-minute period. {43}

Physostigmine is contraindicated in hypotensive reactions. {43}

ECG monitoring is recommended during physostigmine administration. {43}

Excitement may be controlled by diazepam or a short-acting barbiturate. {43}

It is recommended that 1 mg of atropine be available for immediate injection if the physostigmine causes bradycardia, convulsion, or bronchoconstriction. {43}

Supportive therapy may require oxygen and assisted respiration; {43} cool water baths for fever, especially in children; {43} and catheterization for urinary retention. {43} In infants and small children, the body surface should be kept moist. {43}


Patient Consultation
As an aid to patient consultation, refer toAdvice for the Patient, Atropine/Homatropine/Scopolamine (Ophthalmic).

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Before using this medication
»   Conditions affecting use, especially:
Sensitivity to atropine, homatropine, or scopolamine





Use in children—Infants and young children and children with blond hair or blue eyes may be especially sensitive to the effects of homatropine; {59} this may increase the chance of side effects during treatment






Use in the elderly—Geriatric patients are more susceptible to the effects of homatropine and similar drugs (such as atropine), thus increasing the potential for systemic side effects {59}
Other medical problems, especially primary glaucoma or predisposition to angle closure

Proper use of this medication
Proper administration technique

Washing hands immediately after application to remove any medication that may be on them; if applying medication to infants or children, washing their hands immediately afterwards {43} also, and not letting any medication get into their mouths; wiping off any medication that may have accidentally gotten on the infant or child, including his or her face {59} and eyelids {43}

Preventing contamination: Not touching applicator tip to any surface; keeping container tightly closed

» Importance of not using more medication than the amount prescribed

» Proper dosing
If dosing schedule is—

• Once a day: Applying as soon as possible if remembered same day; if remembered later, skipping missed dose and going back to regular dosing schedule; not doubling doses


• More than once a day: Applying as soon as possible; if almost time for next dose, skipping missed dose and going back to regular dosing schedule; not doubling doses


» Proper storage

Precautions while using this medication
» Medication causes blurred vision and increased sensitivity of the eyes to light; checking with physician if these effects continue longer than 3 days after discontinuation of homatropine


Side/adverse effects
Signs of potential side effects, especially clumsiness or unsteadiness, confusion or unusual behavior, dryness of skin, fever, flushing or redness of face, hallucinations, skin rash, slurred speech, swollen stomach in infants, tachycardia, unusual drowsiness, tiredness or weakness, and xerostomia


General Dosing Information
Although some manufacturers recommend a dose of 2 drops of an ophthalmic solution at appropriate intervals, the conjunctival sac will usually hold only 1 drop. {63}

More frequent instillation or use of a stronger solution may be required to produce adequate cycloplegia in eyes with brown or hazel irides than in eyes with blue irides. {08}

To avoid excessive systemic absorption, patient should press finger to the lacrimal sac during, and for 2 or 3 minutes following, instillation of the solution. {08}


Ophthalmic Dosage Forms

HOMATROPINE HYDROBROMIDE OPHTHALMIC SOLUTION USP

Usual adult and adolescent dose
Cycloplegic refraction
Topical, to the conjunctiva, 1 or 2 drops of a 2 or 5% solution. May be repeated every five to ten minutes if needed {08} for two or three doses immediately prior to refraction. {60}

Uveitis
Topical, to the conjunctiva, 1 or 2 drops of a 2 or 5% solution{08} two or three times a day. {43} {60} In some cases, a frequency of up to every 3 or 4 hours may be required. {08}{60}

Note: In patients with heavily pigmented eyes, larger doses may be required.{08}



Usual pediatric dose
Cycloplegic refraction
Topical, to the conjunctiva, 1 or 2 drops of a 2% solution {08}{88} {91} every ten minutes for two or three {60}doses immediately prior to refraction. {43} {60}

Uveitis
Topical, to the conjunctiva, 1 or 2 drops of a 2% solution {08} {88} {91} two or three times a day. {60}


Strength(s) usually available
{60}U.S.—


2% (Rx) [Isopto Homatropine{08} (benzalkonium chloride 0.01%)] [Spectro-Homatropine (benzalkonium chloride 0.01%)][Generic]{13}


5% (Rx) [AK-Homatropine{09} (benzalkonium chloride 0.01%)] [I-Homatrine{10}] [Isopto Homatropine{08} ( benzethonium chloride 0.005%)] [Spectro-Homatropine][Generic]{13}

Canada—
{70}

2% (Rx) [Isopto Homatropine{104} (benzalkonium chloride)] [Minims Homatropine{11}][Generic]{30}


5% (Rx) [Isopto Homatropine{104} (benzethonium chloride)][Generic]{30}

Packaging and storage:
Store below 40 °C (104 °F), preferably between 8 and 24 °C (46 and 75 °F){08}, unless otherwise specified by manufacturer. Store in a tight container. Protect from freezing.

Auxiliary labeling:
   • For the eye.
   • Keep container tightly closed.



Revised: 03/01/2000



References
  1. Product Information: Isopto® Homatropine, homatropine hydrobromide. Alcon Ophthalmic, Fort Worth, TX, (PI revised 8/98) reviewed 02/2000.
  1. Ak-Homatropine solution package insert (Akorn—US), Rev 1/86, Rec 5/87.
  1. I-Homatrine solution package insert (International Pharmaceutical Products—US), Rev 1/86, Rec 1/88.
  1. Minims solution 2% (Smith & Nephew). In: Krogh CME, editor. CPS Compendium of pharmaceuticals and specialties. 25th ed. Ottawa: Canadian Pharmaceutical Association, 1990: 640.
  1. Homatropine 2 and 5% generic solutions (lolab). In: PDR Physicians" desk reference for ophthalmology. 19th ed. Oradell, NJ: Medical Economics Data, 1991: 266.
  1. Spectra Homatropine solution package insert (Spectrum Scientific—US), Rev 7/88, Rec 1/90.
  1. Homatropine (Iolab). In: Krogh CME, editor. CPS Compendium of pharmaceuticals and specialties. 25th ed. Ottawa: Canadian Pharmaceutical Association, 1990: Index G20.
  1. Open.
  1. Open.
  1. Open.
  1. Open.
  1. Open.
  1. Panel comments, 7/11/88.
  1. Panel comments on Atropine ophthalmic monograph, 6/14/89.
  1. Panel comments, 6/14/89.
  1. Open.
  1. Olin BR, editor. Drug facts and comparisons. St. Louis: Facts and Comparisons, Inc., 1989 Aug: 477a.
  1. Open.
  1. Krogh CME, editor. CPS Compendium of pharmaceuticals and specialties. 24th ed. Ottawa: Canadian Pharmaceutical Association, 1989: 454, 505, 613.
  1. Havener WH. Ocular pharmacology, 4th ed. St Louis: Mosby, 1978: 222.
  1. Per panel comments for Drug Interactions Project in USP DI-86.
  1. Havener WH. Ocular pharmacology, 5th ed. St Louis: Mosby, 1983: 270.
  1. Trimethobenzamide (Tigan). In: PDR Physicians" desk reference. 45th ed. 1991. Oradell, NJ: Medical Economics Data, 1991: 651.
  1. Hansten PD, Horn JR. Drug interactions. 6th ed. Philadelphia: Lea & Febiger, 1989: 385.
  1. Lake KD, Brown DC. Review article—New drug therapy for kidney stones: A review of cellulose sodium phosphate, acetohydroxamic acid, and potassium citrate. Drug Intell Clin Pharm 1985; 19: 530-9.
  1. Neostigmine Bromide (Prostigmin, ICN). In: PDR Physicians" desk reference. 45th ed. 1991. Oradell, NJ: Medical Economics Data, 1991: 1091.
  1. Panel comments, 6/27/91.
  1. Panel ballot comments, 9/5/91.
  1. Isopto Homatropine ophthalmic solution (Alcon). In: Krogh CME, editor. CPS Compendium of pharmaceuticals and specialties. 28th ed. Ottawa: Canadian Pharmaceutical Association, 1993: 606.
Hide
(web3)