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Isoniazid / pyrazinamide / rifampin Side Effects

For the Consumer

Applies to isoniazid / pyrazinamide / rifampin: oral tablet

In addition to its needed effects, some unwanted effects may be caused by isoniazid / pyrazinamide / rifampin. In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking isoniazid / pyrazinamide / rifampin:

More common
  • Clumsiness or unsteadiness
  • dark urine
  • loss of appetite
  • nausea and vomiting
  • numbness, tingling, burning, or pain in the hands and feet
  • pain in large and small joints
  • unusual tiredness or weakness
  • yellow eyes or skin
Less common
  • Chills
  • difficulty with breathing
  • dizziness
  • fever
  • headache
  • itching
  • muscle and bone pain
  • redness of the skin
  • shivering
  • skin rash
Rare
  • Bloody or cloudy urine
  • blurred vision or loss of vision, with or without eye pain
  • convulsions (seizures)
  • greatly decreased frequency of urination or amount of urine
  • mental depression
  • mood or mental changes
  • sore throat
  • unusual bleeding or bruising

Severity: Minor

Some of the side effects that can occur with isoniazid / pyrazinamide / rifampin may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Diarrhea
  • stomach pain
Less common
  • Sore mouth or tongue

This medicine commonly causes urine, stool, saliva, sputum, sweat, and tears to turn reddish-orange to reddish-brown. This side effect does not usually require medical attention.

Dark urine and yellowing of the eyes or skin (signs of liver problems) caused by isoniazid are more likely to occur in patients 50 years of age and older.

For Healthcare Professionals

Applies to isoniazid / pyrazinamide / rifampin: oral tablet

Hepatic

Frequency not reported: Altered levels of liver enzymes (SGOP, SGPT)

Isoniazid:
Frequency not reported: Elevated serum transaminases (SCOT, SCPT), bilirubinemia, bilirubinuria, jaundice, hepatitis

Pyrazinamide:
Frequency not reported: Hepatotoxicity (e.g., hepatic cell function abnormality, liver tenderness, jaundice, acute yellow atrophy)

Rifampin:
Rare (less than 0.1%): Hepatitis, shock-like syndrome with hepatic involvement
Frequency not reported: Abnormal liver function tests (e.g., elevations in serum bilirubin, alkaline phosphatase, serum transaminases), jaundice[Ref]

Metabolic

Frequency not reported: Altered levels of serum uric acid levels

Isoniazid:
Frequency not reported: Pyridoxine deficiency, pellagra, hyperglycemia, metabolic acidosis

Pyrazinamide:
Frequency not reported: Hyperuricemia, gout, anorexia, porphyria

Rifampin:
Frequency not reported: Anorexia, elevated serum uric acid[Ref]

Dermatologic

Common (1% to 10%): Rash, erythroderma, erythema, exfoliative dermatitis, Lyell syndrome, urticaria, localized skin rash, diffuse skin rash, pruritus, sweating

Isoniazid:
Frequency not reported: Stevens-Johnson syndrome, vasculitis, skin eruptions (morbilliform, maculopapular, purpuric, or exfoliative), rash, pemphigus, acne

Pyrazinamide:
Rare (less than 0.1%): Acne, photosensitivity
Frequency not reported: Rash, urticaria, pruritus, erythema

Rifampin:
Uncommon (0.1% to 1%): Urticaria
Rare (less than 0.1%): Exfoliate dermatitis, pemphigoid reaction, erythema multiforme (Stevens-Johnson syndrome, Lyells syndrome, vasculitis)
Frequency not reported: Flushing, itching with or without a rash (mild, self-limiting), pruritus, rash, pemphigoid reaction, toxic epidermal necrolysis, vasculitis[Ref]

Hypersensitivity

Common (1% to 10%): Generalized hypersensitivity

Isoniazid:
Frequency not reported: Anaphylactic reactions

Pyrazinamide:
Rare (less than 0.1%): Angioedema

Rifampin:
Rare (less than 0.1%): Anaphylaxis[Ref]

Nervous system

Common (1% to 10%): Headache, insomnia, diffuse paresthesia of the legs, anxiety, diabetic coma, tinnitus, vertigo, vertigo with loss of equilibrium

Isoniazid:
Uncommon (0.1% to 1%): Convulsions, toxic encephalopathy, optic neuritis and atrophy, memory impairment
Frequency not reported: Peripheral neuropathy, vertigo, polyneuritis

Rifampin:
Frequency not reported: Cerebral hemorrhage, headache, drowsiness, ataxia, dizziness, inability to concentrate, generalized numbness[Ref]

Respiratory

Common (1% to 10%): Coughing, hemoptysis, total pneumothorax

Rifampin:
Frequency not reported: Shortness of breath, wheezing[Ref]

Cardiovascular

Common (1% to 10%): Chest tightness, diffuse chest pain, angina, palpitation, phlebitis

Rifampin:
Frequency not reported: Blood pressure decrease, shock[Ref]

Musculoskeletal

Common (1% to 10%): Arthralgia, long bones pain, localized and diffuse joint pain, edema of the legs

Isoniazid:
Frequency not reported: Rheumatic syndrome, systemic lupus erythematosus-like syndrome

Pyrazinamide:
Frequency not reported: Mild arthralgia, myalgia

Rifampin:
Rare (less than 0.1%): Myopathy
Frequency not reported: Muscular weakness, pain in extremities[Ref]

Gastrointestinal

Common (1% to 10%): Nausea, vomiting, digestive pain, diarrhea

Isoniazid:
Frequency not reported: Pancreatitis, nausea, vomiting, epigastric distress, constipation, dry mouth

Pyrazinamide:
Frequency not reported: Nausea, vomiting, peptic ulcer aggravation

Rifampin:
Frequency not reported: Heartburn, epigastric distress, nausea, vomiting, flatulence, cramps, diarrhea, pseudomembranous colitis, abdominal discomfort, sore mouth, sore tongue[Ref]

Other

Common (1% to 10%): Spiking fever, persistent fever

Isoniazid:
Frequency not reported: Fever

Pyrazinamide:
Rare (less than 0.1%): Malaise, fever

Rifampin:
Very common (10% or more): "Flu" syndrome (episodes of fever, chills, headache, dizziness, bone pain; up to 50%)
Frequency not reported: Fatalities, fever, fatigue, edema of the face and extremities[Ref]

Endocrine

Isoniazid:
Frequency not reported: Gynecomastia

Rifampin:
Rare (less than 0.1%): Adrenal insufficiency
Frequency not reported: Menstrual disturbances[Ref]

Genitourinary

Pyrazinamide:
Frequency not reported: Dysuria[Ref]

Hematologic

Isoniazid:
Frequency not reported: Agranulocytosis, anemia (hemolytic, sideroblastic, aplastic), thrombocytopenia, eosinophilia

Pyrazinamide:
Rare (less than 0.1%): Thrombocytopenia with or without purpura, sideroblastic anemia with erythroid hyperplasia, vacuolation of erythrocytes, increased serum concentration, adverse effects on blood clotting mechanisms

Rifampin:
Rare (less than 0.1%): Disseminated intravascular coagulation, agranulocytosis, hemolysis, hemoglobinuria, hematuria
Frequency not reported: Thrombocytopenia with or without purpura, leukopenia, hemolytic anemia, decreased hemoglobin, eosinophilia[Ref]

Immunologic

Isoniazid:
Frequency not reported: Anti-nuclear antibodies, lymphadenopathy[Ref]

Ocular

Isoniazid:
Frequency not reported: Visual disorders

Rifampin:
Frequency not reported: Visual disturbances, conjunctivitis[Ref]

Renal

Pyrazinamide:
Rare (less than 0.1%): Interstitial nephritis

Rifampin:
Rare (less than 0.1%): Interstitial nephritis, acute tubular necrosis, renal insufficiency, acute renal failure
Frequency not reported: Elevated BUN[Ref]

Psychiatric

Isoniazid:
Uncommon (0.1% to 1%): Toxic psychosis

Rifampin:
Rare (less than 0.1%): Psychoses
Frequency not reported: Mental confusion, behavioral changes[Ref]

References

1. "Product Information. Rifater (isoniazid / pyrazinamide / rifampin)." SmithKline Beecham, Philadelphia, PA.

Not all side effects for isoniazid / pyrazinamide / rifampin may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.

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