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Blocadren Side Effects

Generic Name: timolol

Note: This document contains side effect information about timolol. Some of the dosage forms listed on this page may not apply to the brand name Blocadren.

For the Consumer

Applies to timolol: oral tablet

Along with its needed effects, timolol (the active ingredient contained in Blocadren) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking timolol:

More common
  • Chest pain or discomfort
  • lightheadedness, dizziness, or fainting
  • shortness of breath
  • slow or irregular heartbeat
  • unusual tiredness
Less common Rare
  • Noisy breathing
  • small clicking, bubbling, or rattling sounds in the lung when listening with a stethoscope
  • swelling of hands, ankles, feet, or lower legs

Get emergency help immediately if any of the following symptoms of overdose occur while taking timolol:

Symptoms of overdose
  • Blurred vision
  • continuing ringing or buzzing or other unexplained noise in ears
  • headache
  • hearing loss
  • nervousness
  • pounding in the ears
  • sweating

Some side effects of timolol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common
  • Itching skin
  • red, sore eyes
  • Acid or sour stomach
  • belching
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • decreased interest in sexual intercourse
  • feeling of constant movement of self or surroundings
  • heartburn
  • inability to have or keep an erection
  • indigestion
  • lack or loss of strength
  • loss in sexual ability, desire, drive, or performance
  • nausea
  • sensation of spinning
  • stomach discomfort, upset, or pain

For Healthcare Professionals

Applies to timolol: compounding powder, oral tablet


Common (1% to 10%): Bradycardia, arrhythmia, cardiac failure, hypotension, claudication, Raynaud's phenomenon, cold and cyanotic extremities, paranesthesia of the extremities, atrioventricular conduction disturbances
Uncommon (0.1% to 1%): Chest pain, syncope, edema, second or third degree AV block, sinoatrial block, palpitations
Frequency not reported: Cardiac arrest, cerebral vascular accident, worsening of angina pectoris, worsening of arterial insufficiency, vasodilatation[Ref]


Common (1% to 10%): Dyspnea, pulmonary edema, bronchial obstruction
Uncommon (0.1% to 1%): Bronchial spasm (especially in patients with bronchial asthma), rales
Frequency not reported: Cough[Ref]


Common (1% to 10%): Pruritus
Uncommon (0.1% to 1%): Rash
Rare (less than 0.1%): Generalized psoriasis, hyperpigmented nailbeds
Frequency not reported: Skin irritation, increased skin pigmentation, alopecia, hyperhidrosis, worsening of psoriasis, erythematous rashes[Ref]


Common (1% to 10%): Nausea, digestive disorders, constipation, diarrhea, abdominal discomfort
Uncommon (0.1% to 1%): Dyspepsia
Frequency not reported: GI pain, vomiting[Ref]


Frequency not reported: Urinary retention, impotence, decreased libido[Ref]


Frequency not reported: Anaphylaxis[Ref]


Frequency not reported: Arthralgia[Ref]

Nervous system

Common (1% to 10%): Headache, dizziness
Uncommon (0.1% to 1%): Vertigo, paresthesia
Frequency not reported: Local weakness, myasthenia gravis like symptoms[Ref]


Very common (10% or more): Insomnia (10%)
Common (1% to 10%): Nightmares
Uncommon (0.1% to 1%): Hallucinations
Frequency not reported: Depression, somnolence, nervousness, diminished concentration, psychoses, confusion, sleep disturbances[Ref]


Frequency not reported: Nonthrombocytopenic purpura[Ref]


Frequency not reported: Hepatomegaly[Ref]


Frequency not reported: Weight loss, hyperglycemia, hypoglycemia, increased serum triglycerides, increased LDL cholesterol, increased VLDL cholesterol, decreased HDL cholesterol[Ref]


Common (1% to 10%): Eye irritation
Frequency not reported: Visual disturbances, diplopia, ptosis, dry eyes, impaired vision[Ref]


Common (1% to 10%): Fatigue/tiredness, asthenia
Uncommon (0.1% to 1%): Tinnitus
Frequency not reported: Pain in extremity, decreased exercise tolerance, fever[Ref]


Frequency not reported: Retroperitoneal fibrosis[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. "Product Information. Timolol Maleate (timolol)." Mylan Pharmaceuticals Inc, Morgantown, WV.

Some side effects of Blocadren may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.