Timolol (Oral)

Patients diagnosed with high blood pressure or com/health/coma/">glaucoma will usually be prescribed the oral medication Timolol, otherwise known by its brand name of Blocadren.


Oral Timolol is an oral drug that is used to treat a number of conditions, such as high blood pressure, glaucoma and migraines. It can in many cases quickly relieve and clear symptoms, or prevent the condition from becoming worse. Administered in the form of a tablet, it is taken via the mouth twice per day and can be prescribed in doses of between 20 mg and 60 mg per day depending on the patient and the severity of the condition. Patients should take the tablets with meals and water, and should always be upfront with their doctor about other medications being taken, as some can interact with the drug, making it less effective or leading to worsened side effects.

There are various studies into the effectiveness of Timolol in treating glaucoma and other diseases such as high blood pressure, migraines and superficial haemangiomas. These studies affirm the medication's effectiveness, but also show various small risks associated with taking it. Patients should be made aware of these risks and side effects and educated on what to do if any are experienced during their course of medication. Aside from the small risks involved with taking Timolol, the medication has been found to offer a pain-free cure to the aforementioned conditions in many cases and is generally a safe solution to easing symptoms associated with them.

Conditions treated

  • High blood pressure
  • Migraines
  • Glaucoma

Type of medicine

  • Oral

Side effects

The following side effects are fairly common among patients taking a course of Timolol and are not usually a cause for concern. However, as is the case with most types of medication, if any of the symptoms persist, patients should seek advice from their healthcare professional as soon as possible.

Side effects include:

  • dry mouth
  • drowsiness and general tiredness
  • tingling sensation in the skin
  • runny nose or cough - similar to the symptoms of the common cold
  • general feeling of weakness
  • numbness of various areas of skin
  • nausea or vomiting
  • headache
  • insomnia or changes in sleeping patterns
  • diarrhea or upset stomach
  • loss of appetite,
  • skin rash or marks on the skin
  • chill in the feet and hands
  • ringing in the ears
  • blurred vision or double vision

Side effects of Timolol are not limited to the above; patients may experience other sensations when taking the medicine. If in doubt about any feelings experienced when taking oral Timolol, patients should contact a doctor for advice without delay.

Less common side effects that have been experienced are below. As a general rule, if a patient experiences any of these, they should contact their healthcare professional immediately as prolonged impact can be serious:

  • dizziness
  • discharge from the eye
  • severe pain or swelling in the eye area
  • muscle weakness in any area
  • slow heartbeat
  • irregular heartbeat
  • changes to mood and mental health
  • severe coldness, numbness, pain in the hands and feet


The prescribed dose of Timolol can vary depending on the individual needs and medical history of the patient. As a general guide, the starting oral dose for this medication is usually 10 mg taken orally, twice per day. It is recommended that each dose is taken with a meal - ideally one at breakfast and one at dinner time.

After you have been on oral Timolol for a specified time period, your doctor may decide to increase your dose. This longer-term maintenance dose is usually set at between 10 mg and 20 mg, depending on the individual.

For severe or persistent cases of any of the associated conditions, the doctor may prescribe a maximum dose of 30 mg, taken orally twice per day.

You should always leave at least seven days before increasing your dosage and should always consult your doctor first. Do not try to increase your own dosage - sudden increases without medical advice can be a danger to health and may result in heightened side effects.

There have been wide tests in the effectiveness and side effects of this medication in the elderly. This is because diseases such as glaucoma and high blood pressure are much more common as we get older. Countless studies have shown the drug to have a high success rate. Therefore, for elderly patients, this dosage is usually set higher than that of younger patients.

Major drug interactions

You should always tell your doctor if you are on any other medication, or have any other health problems. This is because there are various other drugs that will interact with each other - in some cases impacting the effectiveness of the drugs, and in other cases causing severe reactions of side effects. There are various drugs that are considered to interact with oral Timolol. If you are taking one of these drugs, you may still be able to take Timolol; however, the dosage that your doctor will prescribe could be altered as a result. There are 752 drugs that have been found to have a moderate interaction with Timolol, including branded and generic drugs.

There are, however, some drugs that should not be taken at all with Timolol due to the severity of the potential reaction. This is called a major interaction - and this is why it's important to always keep a record of the medication you are taking and should always be open about it when being prescribed a new medication. There are 67 drugs that have been found to have a major interaction with Timolol, listed in alphabetical order below:

  • albuterol
  • albuterol, ipratropium
  • aminophylline
  • aminophyllinem, amobarbital, ephedrine
  • aminophylline, guaifenesin, phenobarbital, ephedrine
  • aminophylline, potassium iodide, ephedrine, phenobarbital
  • aminophylline, guaifenesin
  • arformoterol
  • articaine, epinephrine
  • atazanavir
  • atazanavir, cobicistat
  • bitolterol
  • budesonide, formoterol
  • bupivacaine, epinephrine
  • chlorothiazide, methyldopa
  • chlorpheniramine, epinephrine
  • diltiazem
  • diltiazem, enalapril
  • disopyramide
  • dolasetron
  • dyphylline
  • dyphylline, ephedrine, guaifenesin, phenobarbital
  • dyphylline, guaifenesin
  • ephedrine, guaifenesin, theophylline
  • ephedrine, hydroxyzine, theophylline
  • ephedrine, phenobarbital, potassium iodide, theophylline
  • ephedrine, phenobarbital, theophylline
  • epinephrine
  • epinephrine, etidocaine
  • epinephrine, lidocaine
  • epinephrine, prilocaine
  • fingolimod
  • fluticasone, salmeterol
  • fluticasone, umeclidinium, vilanterol
  • fluticasone, vilanterol
  • formoterol
  • formoterol, glycopyrrolate
  • formoterol, mometasone
  • glycopyrrolate, indacaterol
  • guaifenesin, oxtriphylline
  • guaifenesin, theophylline
  • hydrochlorothiazide, methyldopa
  • indacaterol
  • isoetharine
  • levalbuterol
  • metaproterenol
  • methacholine
  • methyldopa
  • mixed grass pollens allergen extract
  • olodaterol
  • olodaterol, tiotropium
  • oxtriphylline
  • pirbuterol
  • potassium iodide, theophylline
  • racepinephrine
  • ragweed pollen allergen extract
  • ritodrine
  • salmeterol
  • saquinavir
  • ┬áterbutaline
  • theophylline
  • timothy grass pollen allergen extract
  • tizanidine
  • trandolapril, verapamil
  • umeclidinium, vilanterol
  • verapamil


There are various warnings for those taking Timolol, aside from the aforementioned major drug interactions.

Food and alcohol interactions

As is the case with many medications, it is not advisable to drink alcohol when undergoing a course of Timolol. Alcohol can generally impact the effectiveness of treatment and can also heighten many of the symptoms of the medication. The medication may also make the user more vulnerable to the effects of alcohol.

When taken together, alcohol and Timolol may lower the blood pressure. As a result, patients that take both can experience extreme light-headedness, dizziness, headaches, changes in the heart rate (either slowing down or speeding up) - and even fainting in some cases. Patients should be particularly wary of taking alcohol when they are at the beginning of their treatments, as this is the time when the body is most vulnerable to the side effects of the drug. You should also be mindful if you have recently had a dose increase; again, the body will not be used to that level of Timolol and therefore alcohol may accentuate any side effects.

If you have taken alcohol and experience severe symptoms, contact your doctor for advice if these symptoms persist.

When taking Timolol, patients should also avoid taking multivitamins with minerals. These have been found to impair the effects of Timolol. If you are taking multivitamins with minerals and have been prescribed a course of Timolol, try taking your vitamins and your medication several hours apart. When you let your doctor know that you are taking multivitamins, he/she may alter the dose of Timolol.

Other diseases

In addition to other medications and food/alcohol, you should also tell your doctor if you experience any other medical conditions. Timolol may make these other conditions worse or vice versa - the conditions may impact on the effectiveness of Timolol:


Timolol should be used with caution in young people and children. It should generally be used with extreme caution in infants, babies and young children - as a result, it is not usually prescribed to patients of a very young age. In the rare instance that the medication is prescribed to children, parents should keep a close eye out for coughing, wheezing or pauses in breathing. If any of these side effects occur, the medication should be stopped immediately and a doctor should be contacted as soon as possible.

Pregnancy and breastfeeding

Timolol should not be used during pregnancy. It should also not be taken by nursing mothers as the substance has been found to get into the milk. Timolol consumed by through breast milk can cause harm to your baby.

Missing a dose

If you miss taking a tablet of Timolol, there's no need to worry. You can take it when you remember. However, skip the missed dose entirely if you find it is already close to time for your next dose. Do not attempt to take more of the medication - or double doses - to make up for missed doses. This will not have a positive impact on the effectiveness of the medication and could cause a reaction or side effects.


Always store your prescription of oral Timolol in a clean, dry environment at room temperature (21 degrees centigrade). Keep the medication away from any direct light sources, sunlight or any other heat sources. Storing the medication at temperatures that are too hot or too cold may impair its effectiveness. Do not store in rooms with temperatures over 25 degrees.

You should also always store Timolol in the container with which it was supplied. Often containers are fitted with tamper-proof lids that prevent them being accessed or consumed by children. If the medication does not come in one of these containers, keep it in the original box and store it out of sight and reach of children in a cupboard or on a high shelf.

Do not use medication that has passed the expiry date. Using old or expired Timolol could cause unwanted reactions and is usually less effective at treating the diagnosed condition.


If you have leftover Timolol that you no longer require, do not keep it. You should instead dispose of it in a safe and responsible way. Oral tablets should not be placed in garbage cans or washed down sinks. Nor should they be ground. You should instead first check for any local take-back schemes in your area. These schemes are run by the FDA and exist to help reduce the amount of medication that can fall into the wrong hands, harm the environment or be consumed by animals.

When a convenient take-back scheme is not available to book in your area, there are various other steps you can take to ensure the safe disposal of your medication. First, without grinding the tablets, you should mix them with an inedible substance such as soil or dirt - or even used coffee powder or beans. Then you should put the mixture into a sealable bag. Seal the bag tightly and then place it in your trash can for regular garbage collection. This will prevent human and animal consumption, as well as prevent harm to the environment when disposing of your medication.


Timolol is a highly effective treatment that is prescribed to treat the symptoms of several serious conditions. It has been found to reverse and slow down the effects of glaucoma if treatment is started at an early enough stage. It can also effectively ease migraines and high blood pressure. The drug is easy to administer orally and generally does not result in severe symptoms - except in rare cases.

Timolol is mostly prescribed to older patients due to the nature of glaucoma and high blood pressure and, as such, there are more studies into its effects on elderly patients. As it is not usually required for younger patients, less is known about the side effects and potential health implications - therefore it should be approached with caution when prescribed to children.

Timolol can react with other drugs and health conditions - and there are a large number of other medications that can have major interactions. There are also various diseases or health conditions that could impair the drug's effectiveness. Therefore, it is particularly important with this medication for the patient to be completely upfront with the doctor about all other prescriptions and conditions that they may have.

If used according to guidance and independent of other drugs and substances that cause interactions, this drug is safe for long-term use and is widely used by many people with high success rates.

Last Reviewed:
December 25, 2017
Last Updated:
April 03, 2018