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Timoptol
Brand names: Timoptol
Generic name: Timolol maleate
Manufacturer: MSD Contents: 5 ml
How does it work?
Timoptol eye drops contain the active ingredient timolol maleate, which is a type of medicine called a beta-blocker. It works by blocking beta-receptors in the eye. (NB. Timolol eye drops are also available without a brand name, ie as the generic medicine.)
The pressure within the eyeball is naturally maintained by a continuous flow of liquid called aqueous humour through the eyeball. Aqueous humour is produced by a part of the eye called the ciliary body, and it drains out of the eyeball through channels called the trabecular meshwork. If the outflow of aqueous humour is blocked, the aqueous humour builds up inside the eye, increasing the pressure within the eyeball. This pressure needs to be reduced, as otherwise it can damage the optic nerve and impair vision as a result.
Timolol blocks beta-receptors that are found on the ciliary body. This action reduces the amount of aqueous humour that is secreted into the eyeball by the ciliary body. Timolol also blocks beta-receptors found on the blood vessels that supply the ciliary body. This causes the blood vessels to constrict, and reduces the amount of watery fluid that filters out of the blood vessels to form aqueous humour.
Timolol therefore works by reducing the inflow of aqueous humour into the eyeball, which decreases the pressure within the eye. It is used to treat conditions where there is raised pressure in the eye, such as glaucoma.
Sufficient timolol may be absorbed from the eye into the bloodstream to cause side effects on other parts of the body, or to react with medicines being taken by mouth, injection or suppository. You can minimise the amount of medicine that is absorbed into your bloodstream and increase the local action in the eye, by pressing on your tear duct (the corner of the eye closest to the nose) while putting in the eye drops and for a few minutes after.
Timoptol eye drops are available in metered-dose bottles (Ocumeter) or preservative-free unit-dose vials.
What is it used for?
- Raised pressure within the eye (ocular hypertension)
- Open angle glaucoma
- Glaucoma caused by another disease of the eye (secondary glaucoma)
Warning!
- This medicine is not to be taken by mouth.
- When using these eye drops you should take care to not touch the dropper tip to any surface, or to your eye, in order to avoid contaminating the eye drops.
- Timoptol eye drops are sterile until opened. The metered dose bottles contain a preservative that helps keep the eye drops sterile. Any remaining medicine in the bottle should be carefully disposed of four weeks after the first opening, as after this time it is likely to be contaminated. You may find it helpful to write the date of first opening on the packet. Dispose of carefully, preferably by returning to your pharmacy. The unit dose vials do not contain a preservative and are for single use only.
- Timoptol eye drops in a metered dose bottle contain the preservative benzalkonium chloride, which can be absorbed by soft contact lenses and cause eye irritation. If you wear soft contact lenses, you should remove them before putting in these eye drops. You should wait at least 15 minutes after using the drops before putting your contact lenses back in.
- This medicine may cause temporary blurred vision after you have applied it into the eye(s). If affected, do not drive or operate machinary until this has worn off. You should also take into account that this medicine can sometimes cause other visual disturbances, eg double vision, and dizziness or fatigue, all of which may affect your ability to drive or operate machinary.
- People with diabetes should carefully monitor their blood sugar while using this medicine. This medicine may mask the symptoms of low blood sugar, such as increased heart rate, palpitations, sweating, tremor and nausea.
- This medicine may increase sensitivity to substances which cause allergy and the seriousness of severe allergic reactions (anaphylaxis). People who experience an anaphylactic reaction while taking this medicine may need larger than normal doses of adrenaline to treat the reaction. Seek further medical advice from your doctor if you have a history of allergy.
- While using this medicine you should have regular eye examinations.
Use with caution in
- A problem common in the elderly, related to poor control of the working of the heart (sick sinus syndrome)
- Slowed conduction of electrical messages between the chambers of the heart (1st degree heart block)
- History of severe heart disease
- Increase in the acidity of the blood (metabolic acidosis)
- Hyperthyroidism
- Diabetes
- History of allergies
- History of severe allergic reactions (anaphylaxis)
- Psoriasis
- Abnormal muscle weakness (myaesthenia gravis)
Not to be used in
- Allergy to beta-blockers
- History of asthma
- History of chronic obstructive pulmonary disease (COPD)
- Slow heart rate caused by the pacemaker of the heart (sinus bradycardia)
- Serious defect in the heart's electrical message pathways resulting in decreased function of the heart (2nd or 3rd degree heart block)
- Heart failure
- Failure of the heart to maintain adequate circulation of blood (cardiogenic shock)
- A severe form of angina pectoris, not caused by exertion (Prinzmetal's angina)
- Low blood pressure (hypotension)
- Narrowing of the blood vessels in the hands, causing numb and painful fingers (Raynaud's disease)
- Severe disturbance of blood circulation in the extremities
- Untreated tumour of the adrenal gland (phaeochromocytoma).
- This medicine is not recommended for children.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and Breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- This medicine is not recommended for use in pregnancy unless considered essential by your doctor. If the medicine is continued until delivery, the baby's heart rate and blood sugar should be carefully monitored for the first three to five days following birth. Seek medical advice from your doctor.
- This medicine passes into breast milk and may cause a slow heart rate or low blood sugar in a nursing infant. It is recommended that women who need to use this medicine should not breastfeed their infants. Seek medical advice from your doctor.
Side effects
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
-
Blurred vision
- Inflammation of the membrane that lines the inside of the eyelids and outside of the eyeball, causing redness and discharge (conjunctivitis)
- Inflammation of the eyelids (blepharitis)
- Inflammation of the cornea (keratitis)
- Dry eyes
- Double vision
- Drooping of the upper eyelid (ptosis)
- Headache
- Fatigue
- Chest pain
- Allergic skin reactions
- Disturbed sleep
- Depression
- Low blood pressure (hypotension)
- Dizziness
- Cold hands and feet
- Slow heart rate (bradycardia)
- Disturbances of the gut, such as nausea, vomiting, diarrhoea, indigestion
- Heart block or heart failure
- Shortness of breath (dyspnoea)
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
The timolol in these eye drops can be absorbed into the bloodstream after application to the eye and it may therefore interact with other medicines that you are taking. It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while using this one, to ensure that the combination is safe.
If you are using more than one type of eye drop you should administer them at least five minutes apart, to prevent the second drop washing away the first.
This medicine should not generally be used in combination with the following medicines:
- amiodarone
- beta-blocker medicines taken by mouth, eg atenolol, propranolol
- calcium channel blockers such as bepridil, diltiazem, nifedipine or verapamil.
If this medicine is used by people taking calcium channel blockers such as nifedipine, there may be an increased risk of slow heart rate, low blood pressure or heart failure.
If this medicine is used with any of the following there may be an increased risk of slow heart rate:
- anti-arrhythmic medicines, eg quinidine or dipyridamole
- digoxin.
If this medicine is used with clonidine, there is a risk of a rebound increase in blood pressure if the clonidine is stopped suddenly. If the clonidine needs to be stopped, this medicine should be stopped several days before slowly stopping the clonidine.
In people with diabetes, timolol can prolong the lowering of blood sugar (hypoglycaemia) caused by insulin or other antidiabetic medicines. People with diabetes should monitor their blood sugar, as timolol can also mask the signs of hypoglycaemia.
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