- Type of Drug: Beta-adrenergic-blocking agent.
- Prescribed for: High blood pressure.
Penbutolol (Levatol) General Information
Penbutolol 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.
Cautions and Warnings
You should be cautious about taking Penbutolol if you have asthma, severe heart failure, a very slow heart rate, or heart block because the drug may aggravate these conditions.
People with angina who take Penbutolol 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.
Penbutolol should be used with caution if you have liver or kidney disease, because your ability to eliminate this drug from your body may be impaired.
Penbutolol reduces the amount of blood pumped by the heart with each beat. This reduction in blood 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 Penbutolol 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 all people preparing for surgery.
Penbutolol (Levatol) Possible Side Effects
Side effects are usually mild, relatively uncommon, develop early in the course of treatment, and are rarely a reason to stop taking Penbutolol.
- Most common: male impotence.
- Less common: unusual tiredness or weakness, slow heartbeat, heart failure (swelling of the legs, ankles, or feet), dizziness, breathing difficulty, bronchospasm, mental depression, confusion, 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, drug allergy (fever, sore throat), and liver toxicity.
Penbutolol (Levatol) Drug Interactions
- Penbutolol 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.
- Penbutolol may interfere with the normal signs of low blood sugar and can interfere with the action of oral antidiabetes medicines.
- Penbutolol 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-pressure-lowering effect of Penbutolol.
- Cocaine may reduce the effects of all beta-blocking drugs.
- Penbutolol may increase the cold hands and feet associated with taking ergot alkaloids (for migraine headaches). People taking an ergot and Penbutolol may develop gangrene.
- Penbutolol 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 Penbutolol in the bloodstream and the effect of that drug on the body.
- Penbutolol should not be taken within 2 weeks of taking a monoamine oxidase (MAO) inhibitor antidepressant drug.
- Cimetidine increases the amount of Penbutolol absorbed into the bloodstream from oral tablets.
- Penbutolol may interfere with the effectiveness of Theophylline, Aminophylline, and some antiasthma drugs (especially Ephedrine and Isoproterenol).
- The combination of Penbutolol and Phenytoin or digitalis drugs can result in excessive slowing of the heart, possibly causing heart block.
- If you stop smoking while taking Penbutolol, your dose may have to be reduced because your liver will break down the drug more slowly after you stop.
Penbutolol may be taken without regard to food or meals.
20 mg once a day. Seniors may require more or less medication and must be carefully monitored by their doctors. Those with liver problems may require less medicine.
Penbutolol (Levatol) 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.
Penbutolol is meant to 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. Penbutolol 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 of vivid dreams, upset stomach, trouble sleeping, stuffy nose, frequent urination, unusual tiredness, or weakness.
Penbutolol 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 Penbutolol, take it as soon as you remember. If it is within 8 hours of your next dose, skip the forgotten tablet and continue with your regular schedule. Do not take a double dose.
Penbutolol (Levatol) Special Populations
Infants born to women who took a beta blocker weighed less at birth and had low blood pressure and reduced heart rate. Penbutolol 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 Penbutolol passes into breast milk. Therefore, nursing mothers taking this medicine should bottle-feed their babies.
Older adults may absorb and retain more Penbutolol in their bodies, thus requiring less medicine. 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.