Commonly reported side effects of methotrexate include: increased liver enzymes. See below for a comprehensive list of adverse effects.

Applies to methotrexate: oral solution, oral tablet

Other dosage forms:

• powder for solution, solution

Along with its needed effects, methotrexate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking methotrexate:

More common

• Black, tarry stools
• blood in the urine or stools
• bloody vomit
• diarrhea
• joint pain
• reddening of the skin
• sores in the mouth or lips
• stomach pain
• swelling of the feet or lower legs

Less common

• Back pain
• blurred vision
• confusion
• convulsions (seizures)
• cough or hoarseness
• dark urine
• dizziness
• drowsiness
• fever or chills
• headache
• lower back or side pain
• painful or difficult urination
• pinpoint red spots on the skin
• shortness of breath
• unusual bleeding or bruising
• unusual tiredness or weakness
• yellow eyes or skin

Some side effects of methotrexate may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Hair loss, temporary
• loss of appetite
• nausea or vomiting

Less common

• Acne
• boils on skin
• pale skin
• skin rash or itching

Applies to methotrexate: compounding powder, injectable powder for injection, injectable solution, oral solution, oral tablet, subcutaneous solution

Uncommon (0.1% to 1%): Vasculitis

Rare (less than 0.1%): Pericarditis, pericardial effusion, pericardial tamponade, hypotension, thromboembolic events (e.g., arterial thrombosis, cerebral thrombosis, thrombophlebitis, deep vein thrombosis, retinal vein thrombosis, pulmonary embolism), myocardial ischemia

Frequency not reported: Cerebral edema

Common (1% to 10%): Exanthema, erythema, itching

Uncommon (0.1% to 1%): Urticaria, photosensitivity, depigmentation or hyperpigmentation of the skin, alopecia, increase of rheumatic nodules, painful lesions of psoriatic plaque, herpetiform eruption of the skin, Stevens-Johnson syndrome, toxic epidermal necrolysis (Lyell's syndrome)

Rare (0.01% to 0.1%): Increased pigmentary changes of nails, acne, petechiae, ecchymoses, erythema multiforme, cutaneous erythematous eruptions

Very rare (less than 0.01%): Furunculosis, telangiectasia

Frequency not reported: Exfoliative dermatitis, skin necrosis, skin ulceration, folliculitis, hidradenitis, allergic vasculitis

Uncommon (0.1% to 1%): Inflammation and ulceration of the vagina

Very rare (less than 0.01%): Loss of libido (males and females), impotence, impaired menstruation, vaginal discharge, infertility, abortion, fetal death, fetal defects, gynecomastia, defective oogenesis or spermatogenesis, transient oligospermia, vaginal bleeding

Very common (10% or more): Anorexia, nausea, vomiting, abdominal pain, inflammation, ulcerations of the mucous membrane of mouth and throat (especially during the first 24 to 48 hours after administration), stomatitis, dyspepsia, dehydration

Common (1% to 10%): Diarrhea (especially during the first 24 to 48 hours after administration)

Uncommon (0.1% to 1%): GI bleeding and ulcers, pancreatitis

Rare (0.01% to 0.1%): Gingivitis, enteritis, melena, malabsorption

Very rare (less than 0.01%): Hematemesis, toxic megacolon

Frequency not reported: Glossitis

Generally, the incidence and severity of acute side effects are related to dose and frequency of administration. The most frequently reported adverse reactions include ulcerative stomatitis, leukopenia, nausea, abdominal distress, malaise, undue fatigue, chills and fever, dizziness, and decreased resistance to infection.

Uncommon (0.1% to 1%): Dysuria

Rare (0.01% to 0.1%): Oliguria, anuria, azotemia

Very rare (less than 0.01%): Proteinuria

Frequency not reported: Cystitis, hematuria

Common (1% to 10%): Leukocytopenia, thrombocytopenia, anemia

Uncommon (0.1% to 1%): Pancytopenia, agranulocytosis, hematopoietic disorders

Rare (0.01% to 0.1%): Megaloblastic anemia

Very rare (less than 0.01%): Severe bone marrow depression, aplastic anemia, lymphadenopathy, lymphoproliferative disorders (partly reversible), eosinophilia, neutropenia

Frequency not reported: Hemorrhage, hematoma, myelosuppression

Very common (10% or more): Increase in liver related enzymes (ALAT, ASAT, alkaline phosphatase, bilirubin, and LDH levels) is commonly reported but usually resolves within one month after cessation of therapy

Uncommon (0.1% to 1%): Development of liver fattening, fibrosis and cirrhosis (occurs frequently despite regularly monitored, normal values of liver enzymes), drop of serum albumin

Rare (0.01% to 0.1%): Acute hepatitis, hepatotoxicity

Very rare (less than 0.01%): Reactivation of chronic hepatitis, acute liver degeneration, liver insufficiency, liver failure, liver atrophy, necrosis

Uncommon (0.1% to 1%): Allergic vasculitis, severe allergic reactions progressing to anaphylactic shock

Common (1% to 10%): Disseminated herpes zoster, pneumocystis carinii pneumonia

Very rare (less than 0.01%): Immunosuppression, hypogammaglobulinemia, sepsis, opportunistic infections (may be fatal in some cases), infections caused by the cytomegalic virus, acute paronychia

Frequency not reported: Nocardiosis, cryptococcus mycosis, disseminated herpes simplex, listeria meningitis, mycobacterium avium, intracellular pneumonia, systemic fungal infections (e.g., cryptococcosis, nocardiosis, aspergillosis, histoplasmosis), sepsis, decreased resistance to infection, pneumocystis jiroveci, pneumonia (most common infection), respiratory tract infection, cutaneous bacterial infections, pneumonia, reactivation of hepatitis B infection, worsening of hepatitis C infection

Uncommon (0.1% to 1%): Osteoporosis, arthralgia, myalgia

Rare (0.01% to 0.1%): Stress fracture, nodulosis

Very rare (less than 0.01%): Pain, muscular asthenia or paresthesia of the extremities

Frequency not reported: Osteoporosis, osteonecrosis (aseptic necrosis of the femoral head), soft tissue necrosis, abnormal tissue cell changes, arthralgia/myalgia, back pain

Common (1% to 10%): Headache, fatigue, drowsiness

Uncommon (0.1% to 1%): Vertigo, confusion, seizures, convulsion, encephalopathy

Very rare (less than 0.01%): Paresis, effect on speech including dysarthria and aphasia, myelopathy, changes in sense of taste (metallic taste), meningism, acute aseptic meningitis

Rare (0.01% to 0.1%): Severely impaired vision, visual disturbances, blurred vision

Very rare (less than 0.01%): Conjunctivitis, retinopathy, transient blindness/loss of vision, periorbital edema, blepharitis, epiphora, photophobia, eye discomfort

Frequency not reported: Lymphomas and leukemias have been associated with this drug

Very rare (less than 0.01%): Fever, impaired wound healing

Frequency not reported: Fetal death, fetal damage, abortion, tinnitus, chills, malaise, fatigue

Uncommon (0.1% to 1%): Inflammation and ulceration of the urinary bladder (possibly with hematuria)

Rare (0.01% to 0.1%): Renal failure, elevated serum creatinine and urea level

Frequency not reported: Renal insufficiency (usually with high doses), severe nephropathy

Common (1% to 10%): Pulmonary complications due to interstitial alveolitis pneumonitis (e.g., general illness, dry/nonproductive cough, shortness of breath progressing to rest dyspnea, chest pain, fever)

Uncommon (0.1% to 1%): Pulmonary fibrosis

Rare (0.01% to 0.1%): Pharyngitis, apnea, bronchial asthma

Very rare (less than 0.01%): Pneumocystis carinii pneumonia, chronic obstructive pulmonary disease, pleural effusion

Frequency not reported: Acute pulmonary edema, pleurisy, hypoxia, respiratory failure

Rare (0.01% to 0.1%): Diabetes mellitus, hyperuricemia

Frequency not reported: Metabolic disorder, tumor lysis syndrome

Rare (0.01% to 0.1%): Mood alterations

Very rare (less than 0.01%): Insomnia, cognitive dysfunction

Frequency not reported: Psychosis, depression, confusion, irritability