- Type of Drug: Beta-adrenergic-blocking agent
- Prescribed for: High blood pressure; angina pectoris; glaucoma (eyedrops).
General Information
Carteolol is one of 14 beta-adrenergic-blocking drugs that interfere with the action of a specific part of the nervous system. Beta receptors are found all over the body and affect many body functions. This accounts for the usefulness of beta blockers against a wide variety of conditions. The first member of this group, Propranolol, was found to affect the entire beta-adrenergic portion of the nervous system. Newer beta blockers have been refined to affect only a portion of that system, making them more useful in the treatment of cardiovascular disorders and less useful for other purposes. Other beta blockers are mild stimulants to the heart or have other characteristics that make them more useful for a specific purpose or better for certain people.
When applied to the eye, Carteolol reduces fluid pressure inside the eye by reducing the production of eye fluids and slightly increasing the rate at which fluids flow through and leave the eye. Carteolol produces a greater drop in eye pressure than either Pilocarpine or Epinephrine (other glaucoma drugs), but may be combined with these or other drugs to produce a more pronounced drop in eye pressure.
Cautions and Warnings
You should be cautious about taking Carteolol if you have asthma, severe heart failure; a very slow heart rate, or heart block because the drug may aggravate these conditions. Compared with many other beta blockers, Carteolol has less of an effect on your pulse and bronchial muscles (asthma), has less of a rebound effect when discontinued, and produces less tiredness, depression, and intolerance to exercise.
People with angina who take Carteolol for high blood pressure should have their drug dosage reduced gradually over 1 to 2 weeks rather than suddenly discontinued to avoid possible aggravation of the angina.
Carteolol should be used with caution if you have liver or kidney disease because the ability to eliminate this drug from your body may be impaired.
Carteolol reduces the amount of blood pumped by the heart with each beat. This reduction in bipod flow can aggravate or worsen the condition of people with poor circulation or circulatory disease.
If you are undergoing major surgery, your doctor may want you to stop taking Carteolol at least 2 days before surgery to permit the heart to respond more acutely to things that happen during the surgery. This is still controversial and may not hold true for alPpeople preparing for Surgery.
Carteolol eyedrops should not be used by people who cannot take oral beta-blocking drugs, such as Propranolol.
Possible Side Effects
Side effects are usually mild, are relatively uncommon, develop early in the course of treatment, and are rarely a reason to stop taking Carteolol.
- Most common: impotence.
- Other: unusual tiredness or weakness, slow heartbeat, heart failure (swelling of the legs, ankles, or feet), dizziness, breathing difficulty, bronchospasm, mental depression, anxiety, nervousness, sleeplessness, disorientation, short-term memory loss, emotional instability, cold hands and feet, constipation, diarrhea, nausea, vomiting, upset stomach, increased sweating, urinary difficulty, cramps, blurred vision, skin rash, hair loss, stuffy nose, facial swelling, aggravation of lupus erythematosus (a disease of the body’s connective tissues), itching, chest pains, back or joint pains, colitis, and drug allergy (fever, sore throat).
Drug Interactions
- Carteolol may interact with surgical anesthetics to increase the risk of heart problems during surgery. Some anesthesiologists recommend gradually stopping your medicine 2 days before surgery.
- Carteolol may interfere with the normal signs of low blood sugar and can interfere with the action of oral antidiabetes medicines.
- Carteolol enhances the blood-pressure-lowering effects of other blood-pressure-reducing agents (including Clonidine, Guanabenz, and Reserpine) and calcium-channel-blocking drugs (such as Nifedipine).
- Aspirin-containing drugs, Indomethacin, Sulfinpyrazone, and estrogen drugs can interfere with the blood-pressurelowering effect of Carteolol.
- Cocaine may reduce the effects of all beta-blocking drugs.
- Carteolol may increase the cold hands and feet associated with taking ergot alkaloids (for migraine headaches). Gangrene is a possibility in people taking an ergot and Carteolol.
- Carteolol will counteract the effects of thyroid-hormone- replacement medicines.
- Calcium channel blockers, Flecainide, Hydralazine, oral contraceptives, Propafenone, Haloperidol, phenothiazine tranquilizers (Molindone and others), quinolone antibacterials, and Quinidine may increase the amount of Carteolol in the bloodstream and the effect of that drug on the body.
- Carteolol should not be taken within 2 weeks of taking a monoamine oxidase (MAO) inhibitor antidepressant drug.
- Cimetidine increases the amount of Carteolol absorbed into the bloodstream from oral tablets.
- Carteolol may reduce the effect of Theophylline, Amino- phylline, and some antiasthma drugs (especially Ephedrine and Isoproterenol).
- The combination of Carteolol and Phenytoin or Digitalis drugs can result in excessive slowing of the heart, possibly causing heart block.
- If you stop smoking while taking Carteolol, your dose may hbve to be reduced because your liver will break down the drug more slowly after you stop.
If you take other glaucoma eye medicines, separate them from Carteolol to avoid physically mixing them. Small amounts of Carteolol are absorbed into the general circulation and may interact with some of the same drugs as other beta blockers, but this is unlikely.
Food Interactions
Carteolol may be taken without regard to food or meals.
Usual Dose
Tablets
2.5 to 10 mg once a day. Taking more than 10 mg per day is not likely to improve the drug’s effect. Those with poor kidney function may take their medication dosage as infrequently as once every 72 hours.
Eyedrops
One drop in the affected eye 1 or 2 times per day.
Overdosage
Symptoms of overdosage are changes in heartbeat (unusually slow, unusually fast, or irregular), severe dizziness or fainting, difficulty breathing, bluish-colored fingernails or palms, and seizures. The overdose victim should be taken to a hospital emergency room where proper therapy can be given. ALWAYS bring the medicine bottle with you.
Special Information
Carteolol should be taken continuously. Do not stop taking it unless directed to do so by your doctor; abrupt withdrawal may cause chest pain, difficulty breathing, increased sweating, and unusually fast or irregular heartbeat. The dose should be lowered gradually over a period of about 2 weeks.
Call your doctor at once if any of the following symptoms develop: back or joint pains, difficulty breathing, cold hands or feet, depression, skin rash, or changes in heartbeat. This drug may produce an undesirable lowering of blood pressure, leading to dizziness or fainting. Call your doctor if this happens to you. Call your doctor about the following side effects only if they persist or are bothersome: anxiety, diarrhea, constipation, sexual impotence, headache, itching, nausea or vomiting, nightmares or vivid dreams, upset stomach, trouble sleeping, stuffy nose, frequent urination, unusual tiredness, or weakness.
Carteolol can cause drowsiness, light-headedness, dizziness, or blurred vision. Be careful when driving or performing complex tasks.
It is best to take your medicine at the same time each day. If you forget a dose of Carteolol tablets, take it as soon as you remember. If you take your medicine once a day and it is within 8 hours of your next dose, skip the forgotten tablet and continue with your regular schedule. If you take your medicine twice a day and it is within 4 hours of your next dose, skip the forgotten dose and continue with your regular schedule. Do not double the dose.
To administer the eyedrops, lie down or tilt your head backward and look at the ceiling. Hold the dropper above your eye and drop the medicine inside your lower lid while looking up. To prevent possible infection, don’t allow the dropper to touch your fingers, eyelids, or any surface. Release the lower lid and keep your eye open. Don’t blink for about 30 seconds. Press gently on the bridge of your nose at the inside corner of your eye for about 1 minute. This will help circulate the medicine around your eye. Wait at least 5 minutes before using any other eyedrops.
If you forget to take a dose of Carteolol eyedrops, take it as soon as you remember. If it is almost time for your next dose, skip the one you forgot and continue with your regular schedule. Do not take a double dose.
Special Populations
Pregnancy/Breast-feeding
Infants born to women who took a beta blocker weighed less at birth, and had low blood pressure and reduced heart rate. Carteolol should be avoided by pregnant women and those who might become pregnant while taking it. When the drug is considered essential by your doctor, its potential benefits must be carefully weighed against its risks.
It is not known if Carteolol passes into breast milk. Nursing mothers taking this medicine should bottle-feed their babies.
Seniors
Older adults may absorb and retain more Carteolol, thus requiring less medicine to achieve the same results. Your doctor will need to adjust your dosage to meet your individual needs. Seniors taking this medicine may be more likely to suffer from cold hands and feet, reduced body temperature, chest pains, general feelings of ill health, sudden breathing difficulty, increased sweating, or changes in heartbeat.