Consumer Information
Pemirolast (Ophthalmic)
USAN:
Pemirolast Potassium{03}
INN:
Pemirolast{03}
JAN:
Pemirolast{03}
VA CLASSIFICATION
Primary: OP801
Commonly used brand name(s): Alamast.
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).
†Not commercially available in Canada.
Category:
Mast cell stabilizer (ophthalmic) —
Antiallergic (ophthalmic)—
Indications
Accepted
Conjunctivitis, allergic (prophylaxis)—Pemirolast ophthalmic solution is indicated for the prophylaxis of itching of the eye associated with allergic conjunctivitis.{01}
Pharmacology/Pharmacokinetics
Physicochemical characteristics:
Molecular weight—
Pemirolast: 266.3{01}
Solubility
Freely soluble in water.{01}
pH
8.0.{01}
Mechanism of action/Effect:
Pemirolast is a mast cell stabilizer and inhibits the release of inflammatory mediators from cells associated with Type I immediate hypersensitivity reactions. The drug has been observed to block antigen-stimulated calcium ion influx into mast cells. Pemirolast also inhibits the chemotaxis of eosinophils into ocular tissue, and prevents inflammatory mediator release from human eosinophils.{01}
Biotransformation:
Liver—Extent unknown.{01}{02}
Half-life:
Elimination—Mean of 4.5 hours.{01}{02}
Onset of action:
Up to 4 weeks.{01}
Time to peak concentration:
Mean of 0.42 hours.{01}
Peak serum concentration:
A mean peak plasma level of 4.7 ng/mL occurred after 2 weeks of administration.{01}
Elimination:
Renal, 84 to 90% of dose eliminated within 24 hours{02}; about 10 to 15% of the dose was excreted unchanged{01}.
Precautions to Consider
Carcinogenicity/Mutagenicity
Pemirolast was neither clastogenic nor mutagenic when studied in a series of bacterial and mammalian gene mutation and chromosomal injury tests in vitro. Additional in vivo studies in rats did not reveal clastogenesis after exposure to pemirolast.{01}
Pregnancy/Reproduction
Fertility—
Pemirolast did not affect mating and fertility in rats exposed to oral doses of up to 250 mg/kg (approximately 20,000 times the recommended human dose).{01}
Pregnancy—
There are no adequate and well-controlled studies in pregnant women. However, when given to rats at oral doses of 250 mg/kg or more (approximately 20,000 times the recommended human dose), pemirolast caused increased incidences of interventricular septal defect, fetuses with wavy rib, splitting of thoracic vertebrae, thymic remnant in the neck, and reduced numbers of ossified sternebrae, sacral and caudal vertebrae, and metatarsi. The incidence of renal pelvis/ureteral dilation was also increased in the fetuses and neonates of rats given oral doses of 400 mg/kg (approximately 30,000 times the recommended human dose), during pregnancy. Teratogenicity was not observed in rabbits exposed to oral doses of up to 150 mg/kg (approximately 12,000 times the recommended human dose).{01}
An increase was observed in the incidence of pre- and post-implantation losses, as well as in the number of embryo/fetal survival failures, decreased neonatal body weight, and delays in neonatal development in rats exposed to oral doses of pemirolast 400 mg/kg. Reductions in the number of corpus lutea, the number of implantations, and the number of live fetuses was observed in the F1 generation of rats descendent from Fodams given oral doses of pemirolast 250 mg/kg or more during late gestation and lactation periods.{01}
FDA Pregnancy Category C
Breast-feeding
It is not known whether pemirolast is distributed into human breast milk. However, pemirolast is distributed in the milk of lactating rats at concentrations higher than those in plasma. Caution should be exercised when pemirolast is administered to nursing women. Problems in humans have not been established.{01}
Pediatrics
The safety and effectiveness of pemirolast has not been established for children below the age of 3 years. {01}
Geriatrics
No information is available on the relationship of age to the effects of pemirolast in geriatric patients.
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 problem exists:
» Sensitivity to pemirolast
Risk-benefit should be considered when the following medical problems exist
Contact lens-related irritation (Pemirolast should not be used to treat the symptoms of contact lens-related irritation.{01})
Side/Adverse Effects
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
Incidence less frequent
Bronchitis (cough, producing mucus; difficulty breathing; tightness in chest)
dysmenorrhea (increased stomach pain and cramping; painful menstrual bleeding)
sinusitis (headache; pain and tenderness around eyes and cheekbones ; runny or stuffy nose)
{01}
Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
Cold/flu symptoms (chills; cough; fever; headache; runny or stuffy nose; sneezing; sore throat)
headache
{01}
Incidence less frequent
Allergy (itching; redness; eyelid swelling )
back pain
cough
fever
foreign body sensation in eye
burning, dryness, and discomfort of eye (burning sensation in eye; eye discomfort; dryness of eyes)
sneezing and nasal congestion (stuffy nose)
Overdose
For more information on the management of overdose or unintentional ingestion, contact a poison control center (see Poison Control Center Listing).
No information is available regarding the occurrence of overdose with ophthalmic preparations of pemirolast{01}.
Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Pemirolast (Ophthalmic).
In providing consultation, consider emphasizing the following selected information (» = major clinical significance):
Before using this medication
» Conditions affecting use, especially:
Sensitivity to pemirolast
Use in children—The safety and effectiveness of pemirolast in children below the age of 3 years have not been established.
Proper use of this medication
» To prevent contamination of the medicine dropper tip and solution, not touching eyelids or the surrounding areas with the dropper tip; keeping the bottle tightly closed when not in use{01}
» Proper dosing
Applying it as soon as possible; not using if almost time for next dose; using next dose at regularly scheduled time; not doubling doses
Proper storage
Precautions while using this medication
» Possible absorption by soft contact lenses of preservative used with pemirolast ophthalmic solution; for patients whose eyes are not red, and who wear contact lenses, waiting at least 10 minutes after applying pemirolast ophthalmic solution before they insert contact lenses{01}
Side/adverse effects
Signs of potential side effects, especially bronchitis, dysmenorrhea, or sinusitis
For ophthalmic dosing form:
Symptomatic response to treatment (decreased itching) may occur within a few days, yet may require up to 4 weeks of therapy{01}.
Pemirolast is intended for topical ophthalmic use only. It should not be used orally or for injection. {01}
Ophthalmic Dosage Form
PEMIROLAST POTASSIUM OPHTHALMIC SOLUTION
Usual Adult Dose
Conjunctivitis, allergic
Topical, to the conjunctiva of the eye, 1 or 2 drops in each affected eye four times daily{01}.
Usual Pediatric Dose
Conjunctivitis, allergic
Children older than 3 years of age: See Usual adult dose.
Children up to 3 years of age: Safety and efficacy have not been established.
Usual Geriatric Dose
See Usual adult dose.
Strength(s) usually available
U.S.—
0.1% (Rx) [Alamast (10 mg per 10 mL bottle) (lauralalkonium chloride 0.005%)]
Packaging and storage:
Store between 15 and 25 °C (59 and 77 °F), in a tight container{01}.
Auxiliary labeling:
• For the eye.
• Keep tightly closed
Developed: 04/26/2000
References
- Product Information: Alamast(TM), pemirolast. Santen Inc., Napa, California, (PI revised 9/1999) reviewed 4/2000..
- Tanaka M: Pemirolast potassium. Drugs Today 1992; 28(1):29–31.
- Canada JR (ed). The USP dictionary of USAN and international drug names 1998. The United States Pharmacopeial Convention Inc, Rockville, MD; 1997:554.
