Presented by :ARIF KHAN

4th GROUP

5th YEAR

Ethambutol is used with other medications to

treat tuberculosis (TB). Ethambutol is an

antibiotic and works by stopping the growth

of bacteria.

This antibiotic treats only bacterial

infections. It will not work for viral infections

(such as common cold, flu). Unnecessary use

or misuse of any antibiotic can lead to its

decreased effectiveness

This drug may also be used with other

medications to help treat a certain serious

infection (Mycobacterium avium complex-

MAC). It may also be used with other

medications to prevent the MAC infection

from occurring again in people with

advanced HIV disease.

It is sold under the trade

names Myambutol and Servambutol.

Ethambutol diffuses into actively growing M.

tuberculosis such as tubercle bacilli.

Ethambutol 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 antimicrobial

agents has been demonstrated.

It is well absorbed from

the gastrointestinal tract and well

distributed in body tissues and

fluids. 50% is excreted unchanged in

urine.

Ethambutol is distributed to most tissues and

body fluids, except CSF. Ethambutol does not

penetrate intact meninges, but 10 to 50%

may penetrate the meninges of patients with

tuberculous meningitis.

Rifampin—High to very high (89%).

Isoniazid—Very low (0 to 10%).

Pyrazinamide—Low (10 to 20%).

Pyrazinoic acid—Low (approximately 31%).

Ethambutol—Low (20 to 30%).

Up to 15% of ethambutol is metabolized to

inactive metaboliteIsoniazid—1 to 2 hours{08}{09}.

Pyrazinamide—1 to 2 hours

Pyrazinoic acid—4 to 5 hours

Ethambutol—2 to 4 hours

Time to peak serum concentration

Rifampin—1.5 to 4 hours after oral

administration

Ethambutol:

2 to 5 mcg/mL after a single dose of 25

mg/kg.

Ethambutol—

Renal; by glomerular filtration and

tubular secretion; up to 80% excreted within

24 hours (at least 50% excreted unchanged

and up to 15% as inactive metabolites).

Fecal; 20% excreted unchanged.

In dialysis—

ethambutol is removed from the blood

by hemodialysis and peritoneal dialysis.

Incidence more frequent:

Hepatitis (dark urine; yellow eyes or skin)

hepatitis prodromal symptoms (loss of

appetite; nausea and vomiting; unusual

tiredness or weakness)

peripheral neuritis (clumsiness or

unsteadiness; numbness, tingling, burning, or

pain in hands and feet )

“Flu-like” syndrome (chills; difficulty in

breathing; dizziness; fever; headache;

muscle and bone pain; shivering)

gouty arthritis, acute (chills; pain and

swelling of joints, especially big toe, ankle,

or knee; tense, hot skin over affected joints)

hypersensitivity (itching; redness; skin

rash).

Incidence less frequent

Blood dyscrasias (sore throat; unusual

bleeding or bruising)

interstitial nephritis (bloody or cloudy urine;

greatly decreased frequency of urination or

amount of urine)

neurotoxicity (seizures; mental depression;

mood or other mental changes )

retrobulbar optic neuritis (blurred vision or

loss of vision, with or without eye pain).

Incidence rare

Before taking ethambutol, tell your doctor or

pharmacist if you are allergic to it; or if you

have any other allergies. This product may

contain inactive ingredients, which can cause

allergic reactions or other problems.

Before using this medication, tell your

doctor or pharmacist your medical history,

especially of: eye problems (such as optic

neuritis, cataracts, diabetic

retinopathy),liver disease, kidney disease,

alcohol use.

Ethambutol crosses the placenta, resulting in

fetal plasma concentrations that are

approximately 30% of maternal plasma

concentrations. However, problems in humans

have not been documented.

Disulfiram (concurrent use in alcoholics

may result in increased incidence of CNS

effects such as dizziness, incoordination,

irritability, or insomnia; reduced dosage or

discontinuation of disulfiram may be

necessary.

For specific information on the agents used

in the management of rifampin, isoniazid,

pyrazinamide, and ethambutol overdose, :

• Pyridoxine (Systemic) in monograph;

• Diazepam in Benzodiazepines

(Systemic)monograph; and/or

• Thiopental in Barbiturates

(Systemic) monograph.

Conditions affecting use, especially:Hypersensitivity to rifampin, isoniazid, pyrazinamide, ethionamide, niacin (nicotinic acid), rifabutin, rifapentine, or other chemically related medications

Pregnancy—Rifampin, isoniazid, and ethambutolcross the placenta

Breast-feeding—Rifampin, isoniazid, pyrazinamide, and ethambutol are distributed into breast milk

Use in children——Ethambutol generally is not recommended in children whose visual acuity cannot be monitored (younger than 6 years of age)

» Regular visits to physician to check progress, as well as ophthalmologic

examinations if signs of optic neuritis occur

» Checking with physician if no improvement within 2 to 3 weeks

» Using an alternate method of contraception if taking estrogen-containing

oral contraceptives concurrently

» Avoiding alcoholic beverages while taking this medication

» Checking with physician if vascular reactions occur following concurrent

ingestion of cheese or fish with isoniazid-containing medication

» Checking with physician if blurred vision or loss of vision occurs

» Medication causes urine, feces, saliva, sputum, sweat, and tears to turn

reddish-orange to reddish-brown and may also permanently discolor soft

contact lenses; avoiding the wearing of soft contact lenses

http://www.drugs.com/mmx/rifampin-

isoniazid-pyrazinamide-and-ethambutol.html

http://www.webmd.com/drugs/2/drug-

8082/ethambutol-oral/details#

http://www.medicinenet.com/ethambutol-

oral/page2.htm