Prospect: Information for the Patient

Myambutol 400 mg Coated Tablets

Ethambutol

Read this prospect carefully before starting to take this medicine, because

it contains important information for you.

• Keep this prospect, as you may need to read it again.
• If you have any doubts, consult your doctor or pharmacist.
• This medicine has been prescribed only for you and should not be given to others, even if they have the same symptoms as you, as it may harm them.
• If you experience any adverse effects, consult your doctor or pharmacist, even if they are not listed in this prospect. See section 4.

Myambutol belongs to a group of medications called antituberculosos and is indicated for children over 3 months and adults for the treatment of tuberculosis (a lung disease) in all its locations, pulmonary or extrapulmonary, within the usual treatment regimens, with two or three medications, according to the clinical characteristics and in vitro sensitivity of the microorganism involved in tuberculosis.

The medications used differ depending on whether it is an initial treatment or a retreatment. In the latter case, Myambutol must be used in association with medications to which the patient has not developed resistance.

Do not take Myambutol

• if you are allergic to the active ingredient or any of the other components of this medication (listed in section 6).
• if you have diabetic retinopathy or intense optic neuritis (eye diseases), unless your doctor tells you otherwise.
• if you have ever had a severe skin rash or peeling of the skin, blisters, or mouth sores after taking ethambutol.

Warnings and precautions

Consult your doctor or pharmacist before starting to take Myambutol.

• If you have any kidney disease, inform your doctor so that they can prescribe the most suitable dose for you.
• Before starting treatment with ethambutol, an eye examination should be performed and if you notice any changes in vision while taking ethambutol, inform your doctor immediately.
• Young children or patients with difficulty communicating should be closely monitored by parents or caregivers to detect any signs of vision disturbances. It is recommended to perform a routine eye examination when treating young children.
• Patients with high uric acid levels (gout) should be evaluated periodically during treatment with ethambutol.
• Patients with a history of seizures or neurological problems should be strictly controlled during treatment with ethambutol.
• Regular monitoring of liver function tests is recommended for all patients.
• Severe skin reactions, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS), have been reported in relation to treatment with Myambutol. Stop using Myambutol and consult a doctor immediately if you observe any symptoms related to these severe skin reactions described in section 4.

Other medications and Myambutol

Inform your doctor or pharmacist if you are using, have used recently, or may need to use any other medication, especially those used to treat gout, isoniazid, and pyridoxine.

If you are taking antacids, you should take Myambutol at least one hour before the antacid. In the case of antacids containing aluminum hydroxide, the time margin should be at least 4 hours since the administration of Myambutol.

Due to its effect on renal excretion of uric acid, ethambutol may alter the action of uricosuric agents (medications used to treat gout).

Concomitant treatment with disulfiram (used to treat chronic alcoholism) may increase the risk of vision problems.

Etambutol should not be used concurrently with BCG (tuberculosis vaccine)

The concomitant use of ethambutol and ethionamide (tuberculosis medication) may potentiate adverse effects.

The concomitant use of ethambutol and delamanid (tuberculosis medication) may increase the amount of ethambutol in the body.

Pregnancy, breastfeeding, and fertility

If you are pregnant or breastfeeding, think you may be pregnant, or plan to become pregnant, consult your doctor or pharmacist before using this medication.

Driving and operating machinery

This medication may cause vision problems, dizziness, discomfort, confusion, hallucinations, do not drive or operate machinery until you know how you tolerate the treatment.

Myambutol contains saccharose and sorbitol

This medication contains saccharose. If your doctor has told you that you have an intolerance to certain sugars, consult with them before taking this medication.

This medication contains 22.9 mg of sorbitol in each tablet.

Follow exactly the administration instructions of this medication indicated by your doctor or pharmacist. In case of doubt, consult your doctor or pharmacist again.

The recommended dose of ethambutol varies from person to person, depending on your age, weight, and whether it is used for treatment or prevention of tuberculosis. It should not be used as a single antitubercular agent but combined with other medications to avoid the development of resistance.

Adults

• Pulmonary or extrapulmonary primary and latent tuberculosis

Myambutol will be administered in a single daily oral dose of 15 mg/kg (15-20 mg/kg), concomitantly administered medications will be administered at their recommended dosing intervals.

• Retreatment

During the first 60 days of treatment, Myambutol will be administered in a single daily oral dose of 25 mg/kg. Subsequently, the dose should be reduced to 15 mg/kg, maintaining concomitantly administered medications at their recommended dosing intervals.

Use in children

• Treatment of pulmonary or extrapulmonary primary tuberculosis and retreatment

Children <3 months

There are insufficient data to establish a recommendation for children under three months.

Children ≥ 3 months

The usual dose is 20 mg/kg (15-25 mg/kg) per day. The maximum dose is recommended for severe forms of tuberculosis, such as tuberculous meningitis. The maximum daily dose should not exceed the recommended daily dose for adults.

• Treatment of latent tuberculosis

Administer a single daily oral dose of 15 mg/kg, maintaining concomitantly administered medications at their recommended dosing intervals.

Older adults or patients with kidney problems may require blood tests for their doctor to determine if a dose reduction is necessary.

Administration form

• Myambutol tablets should be taken once a day, preferably in the morning before meals.
• Tablets should be swallowed whole with a glass of water, do not chew or crush the tablets.
• If unsure of how many tablets to take or when to take them, ask your doctor or pharmacist.

If you take more Myambutol than you should

If you have taken Myambutol more than you should, consult your doctor or pharmacist immediately or call the Toxicological Information Service, phone: (91) 562 04 20, indicating the medication and the amount ingested.

There is no specific antidote, but gastric lavage may be used if necessary.

If you forgot to take Myambutol

Do not take a double dose to compensate for the missed doses

If you have any other questions about the use of this medication, ask your doctor or pharmacist.

Like all medicines, this medicine may cause side effects, although not everyone will experience them.

The following side effects may be serious:

• Severe allergic reactions, with difficulty breathing, wheezing, palpitations, agitation, or irregular heartbeat.If this occurs, stop taking this medicine and consult your doctor immediately.
• Visual problems, including color blindness. In most cases, it will return to normal after stopping treatment. However, in exceptional circumstances, the problem may take longer to resolve or become permanent.If you notice any change or problem with your vision, contact your doctor immediately.
• Kidney problems. If you have lower back pain, pain, burning, or difficulty urinating or blood in your urine, you should contact your doctor as soon as possible..
• Flat red patches, or circular or coin-shaped patches on the chest, often with central blisters, skin peeling, mouth ulcers, throat, nose, genital, and eye ulcers. These severe skin eruptions may be preceded by fever and flu-like symptoms (Stevens-Johnson syndrome, toxic epidermal necrolysis).
• Generalized erythema, elevated body temperature, and lymph node enlargement (DRESS syndrome or drug hypersensitivity syndrome).

Other possible side effects are:

Rare (may affect up to 1 in 100 people)

• Increased uric acid in the blood
• Decreased visual acuity, loss of vision, color blindness, and/or visual defects, eye pain

Rare (may affect up to 1 in 1,000 people)

• Numbness, tingling, weakness, burning, tremors
• Numbness and pins and needles in the extremities and joints
• Stomach problems, such as loss of appetite, discomfort, weight loss, gas, or stomach pain, vomiting, and diarrhea.
• Liver problems that may cause pale stools, dark urine, or yellowing of the skin or eyes.
• Abnormal liver function test results.
• Allergic reactions, including skin rash and itching

Very rare (may affect up to 1 in 10,000 people)

• Reduction in certain types of blood cells that may increase the risk of infection
• Reduction in platelets in the blood that may cause purple rash, formation of hematomas, or bleeding.
• Severe allergic reactions in the skin with blister formation on the skin, mouth, eyelids, and genitals or skin peeling.
• Skin problems, including hard lumps (tumors) or red patches, often on the back of the arms and hands.
• Gout, whose signs are pain or inflammation in the joints (especially the big toe) with skin sensitivity and heat.
• Dizziness, vertigo, confusion, disorientation, headache, hallucinations
• Pulmonary inflammation, respiratory problems
• Liver failure
• Renal problems
• Discomfort
• Joint pain
• Fever

Reporting side effects

If you experience any type of side effect, consult your doctor or pharmacist, even if it is a possible side effect that does not appear in this prospectus. You can also report them directly through the Spanish System for the Pharmacovigilance of Medicines for Human Use:www.notificaram.es. By reporting side effects, you can contribute to providing more information on the safety of this medicine.

Keep this medication out of the sight and reach of children.

Do not store at a temperature above 25° C.

Do not use this medication after the expiration date that appears on the packaging after CAD. The expiration date is the last day of the month indicated.

Medicines should not be disposed of through drains or trash. Dispose of packaging and unused medications at the SIGRE collection point of the pharmacy. If in doubt, ask your pharmacist how to dispose of packaging and unused medications. By doing so, you will help protect the environment.

Composition of Myambutol

• The active ingredient is etambutol. Each tablet contains 400 mg of etambutol hydrochloride
• The other components are sucrose, gelatin, sorbitol (E420), magnesium stearate (E470b), stearic acid, polydextrose, hydroxypropylmethylcellulose, titanium dioxide (E171), polyethylene glycol 4000, iron oxide black (E172), iron oxide yellow (E172).

Appearance of the product and content of the packaging

Myambutol are round, light gray coated tablets packaged in PVC/Aluminum blisters. Each package contains 100 coated tablets.

Holder of the marketing authorization and responsible manufacturer

Teofarma S.r.l.

Via F.lli Cervi, 8

27010 Valle Salimbene (PV)

Italy

Last review date of this leaflet: July 2024

The detailed and updated information on this medication is available on the website of the Spanish Agency of Medicines and Medical Devices (AEMPS)http://www.aemps.gob.es/.