DRUGS & SUPPLEMENTS
Ethbutol Ethbutol hydrochloride is an oral chemotherapeutic agent which is specifically effective against actively growing microorganisms of the genus Mycobacterium, including M. tuberculosis. The structural formula is:
Ethbutol 100 and 400 mg tablets contain the following inactive ingredients: Gelatin, Hydroxypropyl Methylcellulose, Magnesium Stearate, Sodium Lauryl Sulfate, Sorbitol, Stearic Acid, Sucrose, Titanium Dioxide and other ingredients.
Ethbutol, following a single oral dose of 25 mg/kg of body weight, attains a peak of 2 to 5 mg/mL in serum 2 to 4 hours after administration. When the drug is administered daily for longer periods of time at this dose, serum levels are similar. The serum level of Ethbutol falls to undetectable levels by 24 hours after the last dose except in some patients with abnormal renal function. The intracellular concentrations of erythrocytes reach peak values approximately twice those of plasma and maintain this ratio throughout the 24 hours.
During the 24-hour period following oral administration of Ethbutol approximately 50 percent of the initial dose is excreted unchanged in the urine, while an additional 8 to 15 percent appears in the form of metabolites. The main path of metabolism appears to be an initial oxidation of the alcohol to an aldehydic intermediate, followed by conversion to a dicarboxylic acid. From 20 to 22 percent of the initial dose is excreted in the feces as unchanged drug. No drug accumulation has been observed with consecutive single daily doses of 25 mg/kg in patients with normal kidney function, although marked accumulation has been demonstrated in patients with renal insufficiency.
Ethbutol diffuses into actively growing mycobacterium cells such as tubercle bacilli. Ethbutol appears to inhibit the synthesis of one or more metabolites, thus causing impairment of cell metabolism, arrest of multiplication, and cell death. No cross resistance with other available antimycobacterial agents has been demonstrated.
Ethbutol has been shown to be effective against strains of Mycobacterium tuberculosis but does not seem to be active against fungi, viruses, or other bacteria. Mycobacterium tuberculosis strains previously unexposed to Ethbutol have been uniformly sensitive to concentrations of 8 or less mcg/mL, depending on the nature of the culture media. When Ethbutol has been used alone for treatment of tuberculosis, tubercle bacilli from these patients have developed resistance to Ethbutol (ethambutol hydrochloride) by in-vitro susceptibility tests; the development of resistance has been unpredictable and appears to occur in a step-like manner. No cross resistance between Ethbutol and other antituberculous drugs has been reported. Ethbutol has reduced the incidence of the emergence of mycobacterial resistance to isoniazid when both drugs have been used concurrently.
An agar diffusion microbiologic assay, based upon inhibition of Mycobacterium smegmatis (ATCC 607) may be used to determine concentrations of Ethbutol in serum and urine.
Toxicological studies in dogs on high prolonged doses produced evidence of myocardial damage and failure, and depigmentation of the tapetum lucidum of the eyes, the significance of which is not known. Degenerative changes in the central nervous system, apparently not dose-related, have also been noted in dogs receiving Ethbutol hydrochloride over a prolonged period.
In the rhesus monkey, neurological signs appeared after treatment with high doses given daily over a period of several months. These were correlated with specific serum levels of Ethbutol and with definite neuroanatomical changes in the central nervous system. Focal interstitial carditis was also noted in monkeys which received Ethbutol hydrochloride in high doses for a prolonged period.
INDICATIONS AND USAGE
Ethbutol is indicated for the treatment of pulmonary tuberculosis. It should not be used as the sole antituberculous drug, but should be used in conjunction with at least one other antituberculous drug. Selection of the companion drug should be based on clinical experience, considerations of comparative safety, and appropriate in-vitro susceptibility studies. In patients who have not received previous antituberculous therapy, ie, initial treatment, the most frequently used regimens have been the following:
Ethbutol plus isoniazid
Ethbutol plus isoniazid plus streptomycin.
In patients who have received previous antituberculous therapy, mycobacterial resistance to other drugs used in initial therapy is frequent. Consequently, in such retreatment patients, Ethbutol should be combined with at least one of the second line drugs not previously administered to the patient and to which bacterial susceptibility has been indicated by appropriate in-vitro studies. Antituberculous drugs used with Ethbutol have included cycloserine, ethionamide, pyrazinamide, viomycin and other drugs. Isoniazid, aminosalicylic acid, and streptomycin have also been used in multiple drug regimens. Alternating drug regimens have also been utilized.
Ethbutol is contraindicated in patients who are known to be hypersensitive to this drug. It is also contraindicated in patients with known optic neuritis unless clinical judgment determines that it may be used. Ethbutol is contraindicated in patients who are unable to appreciate and report visual side effects or changes in vision (e.g., young children, unconscious patients).
Ethbutol may produce decreases in visual acuity which appear to be due to optic neuritis. This effect may be related to dose and duration of treatment. This effect is generally reversible when administration of the drug is discontinued promptly. However, irreversible blindness has been reported. (See PRECAUTIONS and ADVERSE REACTIONS ).
Liver toxicities including fatalities have been reported. Baseline and periodic assessment of hepatic function should be performed.
Ethbutol Ethbutol hydrochloride is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.
Patients with decreased renal function need the dosage reduced as determined by serum levels of Ethbutol, since the main path of excretion of this drug is by the kidneys.
Because this drug may have adverse effects on vision, physical examination should include ophthalmoscopy, finger perimetry and testing of color discrimination. In patients with visual defects such as cataracts, recurrent inflammatory conditions of the eye, optic neuritis, and diabetic retinopathy, the evaluation of changes in visual acuity is more difficult, and care should be taken to be sure the variations in vision are not due to the underlying disease conditions. In such patients, consideration should be given to relationship between benefits expected and possible visual deterioration since evaluation of visual changes is difficult..
As with any potent drug, baseline and periodic assessment of organ system functions, including renal, hepatic, and hematopoietic, should be performed.
The results of a study of coadministration of Ethbutol (50mg/kg) with an aluminum hydroxide containing antacid to 13 patients with tuberculosis showed a reduction of mean serum concentrations and urinary excretion of Ethbutol of approximately 20% and 13%, respectively, suggesting that the oral absorption of Ethbutol may be reduced by these antacid products. It is recommended to avoid concurrent administration of Ethbutol with aluminum hydroxide containing antacids for at least 4 hours following Ethbutol administration.
Teratogenic Effects: Pregnancy Category C.
There are no adequate and well-controlled studies in pregnant women. There are reports of ophthalmic abnormalities occurring in
infants born to women on antituberculous therapy that included Ethbutol. Ethbutol should be used during pregnancy
only if the benefit justifies the potential risk to the fetus.
Ethbutol has been shown to be teratogenic in pregnant mice and rabbits when given in high doses. When pregnant mice or
rabbits were treated with high doses of Ethbutol hydrochloride, fetal mortality was slightly but not significantly increased.
Female rats treated with Ethbutol hydrochloride displayed slight but insignificant (P>0.05) decreases in fertility and litter size.
In fetuses born of mice treated with high doses of Ethbutol during pregnancy, a low incidence of cleft palate, exencephaly
and abnormality of the vertebral column were observed. Minor abnormalities of the cervical vertebra were seen in the newborn of
rats treated with high doses of Ethbutol hydrochloride during pregnancy. Rabbits receiving high doses of Ethbutol during
pregnancy gave birth to two fetuses with monophthalmia, one with a shortened right forearm accompanied by bilateral wrist-joint
contracture and one with hare lip and cleft palate.
Ethbutol is excreted into breast milk. The use of Ethbutol should be considered only if the expected benefit to the mother outweighs the potential risk to the infant.
Ethbutol is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.
There are limited data on the use of ethambutol in the elderly. One study of 101 patients, 65 years and older, on multiple drug antituberculosis regimens included 94 patients on Ethbutol. No differences in safety or tolerability were observed in these patients compared with that reported in adults in general. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
Ethbutol may produce decreases in visual acuity, including irreversible blindness, which appear to be due to optic neuritis. Optic neuropathy including optic neuritis or retrobulbar neuritis occurring in association with Ethbutol therapy may be characterized by one or more of the following events: decreased visual acuity, scotoma, color blindness, and/or visual defect. These events have also been reported in the absence of a diagnosis of optic or retrobulbar neuritis.
Patients should be advised to report promptly to their physician any change of visual acuity.
The change in visual acuity may be unilateral or bilateral and hence each eye must be tested separately and both eyes tested together. Testing of visual acuity should be performed before beginning Ethbutol therapy and periodically during drug administration, except that it should be done monthly when a patient is on a dosage of more than 15 mg per kilogram per day. Snellen eye charts are recommended for testing of visual acuity. Studies have shown that there are definite fluctuations of one or two lines of the Snellen chart in the visual acuity of many tuberculous patients not receiving Ethbutol.
The following table may be useful in interpreting possible changes in visual acuity attributable to Ethbutol.
In general, changes in visual acuity less than those indicated under “Significant Number of Lines” and “Decrease Number of Points” may be due to chance variation, limitations of the testing method, or physiologic variability. Conversely, changes in visual acuity equaling or exceeding those under “Significant Number of Lines” and “Decrease Number of Points” indicate need for retesting and careful evaluation of the patient's visual status. If careful evaluation confirms the magnitude of visual change and fails to reveal another cause, Ethbutol should be discontinued and the patient reevaluated at frequent intervals. Progressive decreases in visual acuity during therapy must be considered to be due to Ethbutol.
If corrective glasses are used prior to treatment, these must be worn during visual acuity testing. During 1 to 2 years of therapy, a refractive error may develop which must be corrected in order to obtain accurate test results. Testing the visual acuity through a pinhole eliminates refractive error. Patients developing visual abnormality during Ethbutol treatment may show subjective visual symptoms before, or simultaneously with, the demonstration of decreases in visual acuity, and all patients receiving Ethbutol should be questioned periodically about blurred vision and other subjective eye symptoms.
Recovery of visual acuity generally occurs over a period of weeks to months after the drug has been discontinued. Some patients have received Ethbutol (ethambutol hydrochloride) again after such recovery without recurrence of loss of visual acuity.
Other adverse reactions reported include: hypersensitivity, anaphylactic/anaphylactoid reaction, dermatitis, erythema multiforme, pruritus, and joint pain; anorexia, nausea, vomiting, gastrointestinal upset, and abdominal pain; fever, malaise, headache, and dizziness; mental confusion, disorientation, and possible hallucinations; thrombocytopenia, leucopenia, and neutropenia. Numbness and tingling of the extremities due to peripheral neuritis have been reported.
Elevated serum uric acid levels occur and precipitation of acute gout has been reported. Pulmonary infiltrates, with or without eosinophilia, also have been reported during Ethbutol therapy. Liver toxicities, including fatalities, have been reported (See WARNINGS. ) Since Ethbutol is recommended for therapy in conjunction with one or more other antituberculous drugs, these changes may be related to the concurrent therapy. Hypersensitivity syndrome consisting ot cutaneous reaction (such as rash or exfoliative dermatitis), eosinophilia, and one or more of the following: hepatitis, pneumonitis, nephritis, myocarditis, pericarditis. Fever and lymphadenopathy may be present.
DOSAGE AND ADMINISTRATION
Ethbutol should not be used alone, in initial treatment or in retreatment. Ethbutol should be administered on a once every 24-hour basis only. Absorption is not significantly altered by administration with food. Therapy, in general, should be continued until bacteriological conversion has become permanent and maximal clinical improvement has occurred.
Ethbutol is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.
In patients who have not received previous antituberculous therapy, administer Ethbutol 15 mg/kg of body weight, as a single oral dose once every 24 hours. In the more recent studies, isoniazid has been administered concurrently in a single, daily, oral dose.
In patients who have received previous antituberculous therapy, administer Ethbutol 25 mg/kg (11 mg/lb) of body weight, as a single oral dose once every 24 hours. Concurrently administer at least one other antituberculous drug to which the organisms have been demonstrated to be susceptible by appropriate in-vitro tests. Suitable drugs usually consist of those not previously used in the treatment of the patient. After 60 days of Ethbutol administration, decrease the dose to 15 mg/kg (7mg/ lb) of body weight, and administer as a single oral dose once every 24 hours.
During the period when a patient is on a daily dose of 25 mg/kg, monthly eye examinations are advised.
See Table for easy selection of proper weight-dose tablet(s).
NDC: 50090-0417-2 98 TABLET, FILM COATED in a BOTTLE
Ethbutol TABLET, FILM COATED
Ethbutol pharmaceutical active ingredients containing related brand and generic drugs:
Active ingredient is the part of the drug or medicine which is biologically active. This portion of the drug is responsible for the main action of the drug which is intended to cure or reduce the symptom or disease. The other portions of the drug which are inactive are called excipients; there role is to act as vehicle or binder. In contrast to active ingredient, the inactive ingredient's role is not significant in the cure or treatment of the disease. There can be one or more active ingredients in a drug.
Ethbutol available forms, composition, doses:
Form of the medicine is the form in which the medicine is marketed in the market, for example, a medicine X can be in the form of capsule or the form of chewable tablet or the form of tablet. Sometimes same medicine can be available as injection form. Each medicine cannot be in all forms but can be marketed in 1, 2, or 3 forms which the pharmaceutical company decided based on various background research results.
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.
Ethbutol destination | category:
Destination is defined as the organism to which the drug or medicine is targeted. For most of the drugs what we discuss, human is the drug destination.
Drug category can be defined as major classification of the drug. For example, an antihistaminic or an antipyretic or anti anginal or pain killer, anti-inflammatory or so.
Ethbutol Anatomical Therapeutic Chemical codes:
A medicine is classified depending on the organ or system it acts [Anatomical], based on what result it gives on what disease, symptom [Therapeutical], based on chemical composition [Chemical]. It is called as ATC code. The code is based on Active ingredients of the medicine. A medicine can have different codes as sometimes it acts on different organs for different indications. Same way, different brands with same active ingredients and same indications can have same ATC code.
Ethbutol pharmaceutical companies:
Pharmaceutical companies are drug manufacturing companies that help in complete development of the drug from the background research to formation, clinical trials, release of the drug into the market and marketing of the drug.
Researchers are the persons who are responsible for the scientific research and is responsible for all the background clinical trials that resulted in the development of the drug.
Frequently asked QuestionsCan i drive or operate heavy machine after consuming Ethbutol?
Depending on the reaction of the Ethbutol after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Ethbutol not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.Is Ethbutol addictive or habit forming?
Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.
Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.
Reviewsdrugs.com conducted a study on Ethbutol, and the result of the survey is set out below. It is noteworthy that the product of the survey is based on the perception and impressions of the visitors of the website as well as the views of Ethbutol consumers. We, as a result of this, advice that you do not base your therapeutic or medical decisions on this result, but rather consult your certified medical experts for their recommendations.
Visitor reported usefulNo survey data has been collected yet
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Visitor reported price estimatesNo survey data has been collected yet
Visitor reported frequency of useNo survey data has been collected yet
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The information was verified by Dr. Arunabha Ray, MD Pharmacology