Betimol

Betimol is a prescription medication used to treat increased pressure in the eye caused by glaucoma or a condition called ocular hypertension. Betimol belongs to a group of drugs called beta blockers. It works by decreasing the pressure in the eye.

Betimol comes as an ophthalmic solution (eye drop) and is usually used one drop in the affected eye(s) 1 or 2 times a day. 

Common side effects of Betimol include burning or stinging after placing the drop in the eye, dry eyes, eye discomfort, and headache.

Betimol can also cause blurred vision. Do not drive or operate heavy machinery until you know how Betimol affects you.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include dizziness, headache, slow heartbeats, and trouble breathing.

Tell your doctor about all your current medicines and any you start or stop using, especially:

• any other beta-blocker eye medication--betaxolol, carteolol, levobunolol, or metipranolol;

• any other beta-blocker heart or blood pressure medicine--atenolol, bisoprolol, carvedilol, labetalol, metoprolol, nadolol, propranolol, sotalol, and others; or

• other heart or blood pressure medications--amiodarone, clonidine, digoxin, diltiazem, disopyramide, nicardipine, nifedipine, reserpine, verapamil, and others.

This list is not complete. Other drugs may interact with timolol ophthalmic, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

This section provides information on the proper use of a number of products that contain timolol. It may not be specific to Betimol. Please read with care.

Use this medicine exactly as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

Shake the regular eye drops well just before each use. If you are using the gel-forming eye drops, turn the bottle upside down and shake it once. You do not need to shake the gel-forming eye drops more than once.

To use the eye drops (solution and gel):

• First, wash your hands. Tilt the head back and, pressing your finger gently on the skin just beneath the lower eyelid, pull the lower eyelid away from the eye to make a space. Drop the medicine into this space. Let go of the eyelid and gently close the eyes. Do not blink. Keep the eyes closed and apply pressure to the inner corner of the eye with your finger for 1 or 2 minutes to allow the medicine to be absorbed by the eye.
• Immediately after using the medicine, wash your hands to remove any medicine that may be on them.
• To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). Also, keep the container tightly closed. Serious damage to the eye and possible loss of vision may result from using contaminated eye medicines.

If your doctor ordered two different eye medicines to be used together, wait at least 10 minutes after the regular eye drops before using the second medicine. This will help prevent the second medicine from “washing out” the first one. The gel-forming eye drops should always be the last medicine used if two medicines are ordered. Wait 10 minutes before using the gel-forming eye drops.

You should not use the regular eye drops if you have contact lenses in your eyes. Remove your contact lenses before you use this medicine. Wait at least 15 minutes after you use the medicine before putting the contact lenses back in.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For glaucoma or ocular hypertension:
  • For ophthalmic gel-forming solution dosage form (eye drops):
    • Adults—Use 1 drop in the affected eye once a day.
    • Children—Use and dose must be determined by your doctor. .
  • For ophthalmic solution dosage form (eye drops):
    • Adults and children 2 years of age and older—Use 1 drop in the affected eye two times a day. Your doctor may need to adjust your dose as needed.
    • Children younger than 2 years of age—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, apply it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.

Storage

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

If you are using Timoptic®, use the medicine immediately after opening and throw away any unused medicine after use.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.
• Change in eyesight, eye pain, or very bad eye irritation.
• Shortness of breath, a big weight gain, or swelling in the arms or legs.
• Very bad dizziness or passing out.
• Very bad headache.
• Slow heartbeat.
• A heartbeat that does not feel normal.
• Chest pain.
• Trouble breathing.
• Muscle weakness.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Timolol is a non-selective beta-adrenergic antagonist.

It blocks both beta1-and beta2-adrenergic receptors. Timolol does not have significant intrinsic sympathomimetic activity, local anesthetic (membrane-stabilizing) or direct myocardial depressant activity.

Timolol, when applied topically in the eye, reduces normal and elevated intraocular pressure (IOP) whether or not accompanied by glaucoma. Elevated intraocular pressure is a major risk factor in the pathogenesis of glaucomatous visual field loss. The higher the level of IOP, the greater the likelihood of glaucomatous visual field loss and optic nerve damage. The predominant mechanism of ocular hypotensive action of topical beta-adrenergic blocking agents is likely due to a reduction in aqueous humor production.

In general, beta-adrenergic blocking agents reduce cardiac output both in healthy subjects and patients with heart diseases. In patients with severe impairment of myocardial function, beta-adrenergic receptor blocking agents may inhibit sympathetic stimulatory effect necessary to maintain adequate cardiac function. In the bronchi and bronchioles, beta-adrenergic receptor blockade may also increase airway resistance because of unopposed parasympathetic activity.

Pharmacokinetics

When given orally, timolol is well absorbed and undergoes considerable first pass metabolism. Timolol and its metabolites are primarily excreted in the urine. The half-life of timolol in plasma is approximately 4 hours.

Clinical Studies

In two controlled multicenter studies in the U.S., Betimol® 0.25% and 0.5% were compared with respective timolol maleate eyedrops. In these studies, the efficacy and safety profile of Betimol® was similar to that of timolol maleate.

Summary of Use during Lactation

Because of the variability in excretion of timolol into breastmilk and minimal reported experience during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.

Ophthalmic use of timolol by the mother should pose little risk to the breastfed infant. To substantially diminish the amount of drug that reaches the breastmilk after using eye drops, place pressure over the tear duct by the corner of the eye for 1 minute or more, then remove the excess solution with an absorbent tissue.

Drug Levels

The excretion of beta-adrenergic blocking drugs into breastmilk is largely determined by their protein binding. Those with low binding are more extensively excreted into breastmilk.[1] Accumulation of the drugs in the infant is related to the fraction excreted in urine. With less than 10% protein binding, 20% renal excretion and a relatively short half-life, timolol presents a moderate risk for accumulation in infants, especially neonates.

Maternal Levels. Timolol was measured in milk during the use of ophthalmic drops twice daily in one eye. Although the time of the previous dose was not stated, a predose milk level of 0.5 mcg/L was measured. One and one-half hours after a single drop of 0.5% timolol maleate, the milk level was 5.6 mcg/L. The authors estimated that use of 0.5% timolol drops in one eye twice daily gave the infant 0.63% of a cardiac dose and treatment of both eyes would be 1.25% of a cardiac dose.[2]

A 32-year-old woman was using ophthalmic drops containing 0.5% timolol and 0.2% brimonidine twice daily in the right eye for 6 months. Four milk samples were collected over 6 days, but the times with respect to dosages or nursing were not reported. Milk timolol concentrations ranged from 0 to 0.37 mcg/L. The authors estimated that the maximum dose that a fully breastfed infant would obtain would be 123 ng/kg daily or 0.012% of the weight-adjusted maternal dosage. If the mother had been applying the medication to both eyes, these values would be approximately doubled.[3]

Nine women taking oral timolol 5 mg three times a day had a mean milk timolol level of 15.9 mcg/L (range 2 to 55 mcg/L). In 4 women taking 10 mg three times a day, the mean milk timolol levels was 41 mcg/L (range 7 to 88 mcg/L). The time after the dose when milk was sampled was not stated. In these cases it was estimated that a fully breastfed infant would receive between 0.96 to 1.2% of the maternal weight-adjusted dosage.[4]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

None reported, but beta-adrenergic blocking drugs with similar breastmilk excretion characteristics have caused adverse effects in breastfed newborns.[5][6]

No side effects were reported in one case report of a 9-week-old breastfed infant whose mother was using 0.5% ophthalmic timolol drops twice daily in one eye.[2]

A mother who was taking 2 drops of timolol 0.5% eye drops daily as well as using pilocarpine eye drops twice daily and acetazolamide 250 mg orally twice daily and delivered a preterm infant at 36 weeks of gestation. The infant began 5 months of exclusive breastfeeding at 6 hours after birth. On day 2, the infant developed electrolyte abnormalities consisting of hypocalcemia, hypomagnesemia, and metabolic acidosis. The infant was treated with oral calcium gluconate and a single dose of intramuscular magnesium sulfate. Despite continued breastfeeding and maternal drug therapy, the infant's mild metabolic acidosis disappeared on day 4 of life and the infant was gaining weight normally at 1, 3 and 8 months, but had mild hypotonicity. The authors considered the metabolic effects to be caused by transplacental passage of acetazolamide that resolved despite the infant being breastfed. The infant gained weight adequately during breastfeeding, but had some mild, residual hypertonicity of the lower limbs requiring physical therapy.[2]

A mother used timolol gel-forming solution 0.5% in one eye with punctal occlusion immediately after nursing in the newborn period and a few months later. Her infant was breastfed (extent not stated) during these times and no adverse effects were noted.[7]

Effects on Lactation and Breastmilk

Relevant published information on the effects of beta-blockade or timolol during normal lactation was not found as of the revision date. A study in 6 patients with hyperprolactinemia and galactorrhea found no changes in serum prolactin levels following beta-adrenergic blockade with propranolol.[8]

Alternate Drugs to Consider

(Systemic) Propranolol, Labetalol, Metoprolol, (Ophthalmic) Levobunolol, Metipranolol

References

1. Riant P, Urien S, Albengres E et al. High plasma protein binding as a parameter in the selection of betablockers for lactating women. Biochem Pharmacol. 1986;35:4579-81. PMID: 2878668

2. Lustgarten JS, Podos SM. Topical timolol and the nursing mother. Arch Ophthalmol. 1983;101:1381-2. PMID: 6615302

3. Madadi P, Koren G, Freeman DJ et al. Timolol concentrations in breast milk of a woman treated for glaucoma: calculation of neonatal exposure. J Glaucoma. 2008;17:329-31. PMID: 18552619

4. Fidler J, Smith V, de Swiet M. Excretion of oxprenolol and timolol in breast milk. Br J Obstet Gynaecol. 1983;90:961-5. PMID: 6626493

5. Boutroy MJ, Bianchetti G, Dubruc C et al. To nurse when receiving acebutolol: is it dangerous for the neonate? Eur J Clin Pharmacol. 1986;30:737-9. PMID: 3770068

6. Schimmel MS, Eidelman AI, Wilschanski MA et al. Toxic effects of atenolol consumed during breast feeding. J Pediatr. 1989;114:476-8. PMID: 2921694

7. Johnson SM, Martinez M, Freedman S. Management of glaucoma in pregnancy and lactation. Surv Ophthalmol. 2001;45:449-54. PMID: 11274697

8. Board JA, Fierro RJ, Wasserman AJ et al. Effects of alpha- and beta-adrenergic blocking agents on serum prolactin levels in women with hyperprolactinemia and galactorrhea. Am J Obstet Gynecol. 1977;127:285-7. PMID: 556882

Substance Name

Timolol

CAS Registry Number

26839-75-8

Drug Class

Antihypertensive Agents

Adrenergic Beta-Antagonists

Antiarrhythmics

Antiglaucoma Agents

LactMed Record Number

305

Last Revision Date

20150310

Disclaimer

Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.