General
Because of potential effects of beta-adrenergic blocking agents on blood pressure
and pulse, these agents should be used with caution in patients with cerebrovascular
insufficiency. If signs or symptoms suggesting reduced cerebral blood flow develop
following initiation of therapy with TIMOPTIC, alternative therapy should be
considered.
There have been reports of bacterial keratitis associated with the use of multiple-dose
containers of topical ophthalmic products. These containers had been inadvertently
contaminated by patients who, in most cases, had a concurrent corneal disease
or a disruption of the ocular epithelial surface. (See PRECAUTIONS: Information
for Patients.)
Choroidal detachment after filtration procedures has been reported with the
administration of aqueous suppressant therapy (e.g. timolol).
Angle-closure glaucoma: In patients with angle-closure glaucoma,
the immediate objective of treatment is to reopen the angle. This requires constricting
the pupil. Timolol maleate has little or no effect on the pupil. TIMOPTIC should
not be used alone in the treatment of angle-closure glaucoma.
Anaphylaxis: While taking beta-blockers, patients with a history
of atopy or a history of severe anaphylactic reactions to a variety of allergens
may be more reactive to repeated accidental, diagnostic, or therapeutic challenge
with such allergens. Such patients may be unresponsive to the usual doses of
epinephrine used to treat anaphylactic reactions.
Muscle Weakness: Beta-adrenergic blockade has been reported to
potentiate muscle weakness consistent with certain myasthenic symptoms (e.g.,
diplopia, ptosis, and generalized weakness). Timolol has been reported rarely
to increase muscle weakness in some patients with myasthenia gravis or myasthenic
symptoms.
Information for Patients
Patients should be instructed to avoid allowing the tip of the dispensing container
to contact the eye or surrounding structures.
Patients should also be instructed that ocular solutions, if handled improperly
or if the tip of the dispensing container contacts the eye or surrounding structures,
can become contaminated by common bacteria known to cause ocular infections.
Serious damage to the eye and subsequent loss of vision may result from using
contaminated solutions. (See PRECAUTIONS,
General.)
Patients should also be advised that if they have ocular surgery or develop
an intercurrent ocular condition (e.g., trauma or infection), they should immediately
seek their physician's advice concerning the continued use of the present multidose
container.
Patients with bronchial asthma, a history of bronchial asthma, severe chronic
obstructive pulmonary disease, sinus bradycardia, second or third degree atrioventricular
block, or cardiac failure should be advised not to take this product. (See CONTRAINDICATIONS.)
Patients should be advised that TIMOPTIC contains benzalkonium chloride which
may be absorbed by soft contact lenses. Contact lenses should be removed prior
to administration of the solution. Lenses may be reinserted 15 minutes following
TIMOPTIC administration.
Carcinogenesis, Mutagenesis, Impairment of Fertility
In a two-year study of timolol maleate administered orally to rats, there was
a statistically significant increase in the incidence of adrenal pheochromocytomas
in male rats administered 300 mg/kg/day (approximately 42,000 times the systemic
exposure following the maximum recommended human ophthalmic dose). Similar differences
were not observed in rats administered oral doses equivalent to approximately
14,000 times the maximum recommended human ophthalmic dose.
In a lifetime oral study in mice, there were statistically significant increases
in the incidence of benign and malignant pulmonary tumors, benign uterine polyps
and mammary adenocarcinomas in female mice at 500 mg/kg/day, (approximately
71,000 times the systemic exposure following the maximum recommended human ophthalmic
dose), but not at 5 or 50 mg/kg/day (approximately 700 or 7,000, respectively,
times the systemic exposure following the maximum recommended human ophthalmic
dose). In a subsequent study in female mice, in which post-mortem examinations
were limited to the uterus and the lungs, a statistically significant increase
in the incidence of pulmonary tumors was again observed at 500 mg/kg/day.
The increased occurrence of mammary adenocarcinomas was associated with elevations
in serum prolactin which occurred in female mice administered oral timolol at
500 mg/kg/day, but not at doses of 5 or 50 mg/kg/day. An increased incidence
of mammary adenocarcinomas in rodents has been associated with administration
of several other therapeutic agents that elevate serum prolactin, but no correlation
between serum prolactin levels and mammary tumors has been established in humans.
Furthermore, in adult human female subjects who received oral dosages of up
to 60 mg of timolol maleate (the maximum recommended human oral dosage), there
were no clinically meaningful changes in serum prolactin.
Timolol maleate was devoid of mutagenic potential when tested in vivo (mouse)
in the micronucleus test and cytogenetic assay (doses up to 800 mg/kg) and in
vitro in a neoplastic cell transformation assay (up to 100 mcg/mL). In Ames
tests the highest concentrations of timolol employed, 5,000 or 10,000 mcg/plate,
were associated with statistically significant elevations of revertants observed
with tester strain TA100 (in seven replicate assays), but not in the remaining
three strains. In the assays with tester strain TA100, no consistent dose response
relationship was observed, and the ratio of test to control revertants did not
reach 2. A ratio of 2 is usually considered the criterion for a positive Ames
test.
Reproduction and fertility studies in rats demonstrated no adverse effect on
male or female fertility at doses up to 21,000 times the systemic exposure following
the maximum recommended human ophthalmic dose.
Pregnancy
Teratogenic Effects — Pregnancy Category C. Teratogenicity
studies with timolol in mice, rats, and rabbits at oral doses up to 50 mg/kg/day
(7,000 times the systemic exposure following the maximum recommended human ophthalmic
dose) demonstrated no evidence of fetal malformations. Although delayed fetal
ossification was observed at this dose in rats, there were no adverse effects
on postnatal development of offspring. Doses of 1000 mg/kg/day (142,000 times
the systemic exposure following the maximum recommended human ophthalmic dose)
were maternotoxic in mice and resulted in an increased number of fetal resorptions.
Increased fetal resorptions were also seen in rabbits at doses of 14,000 times
the systemic exposure following the maximum recommended human ophthalmic dose,
in this case without apparent maternotoxicity.
There are no adequate and well-controlled studies in pregnant women. TIMOPTIC
should be used during pregnancy only if the potential benefit justifies the
potential risk to the fetus.
Nursing Mothers
Timolol maleate has been detected in human milk following oral and ophthalmic
drug administration. Because of the potential for serious adverse reactions
from TIMOPTIC in nursing infants, a decision should be made whether to discontinue
nursing or to discontinue the drug, taking into account the importance of the
drug to the mother.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.
Geriatric Use
No overall differences in safety or effectiveness have been observed between
elderly and younger patients.
Last updated on RxList: 1/27/2009