Nalidixic Acid Side Effects

Medically reviewed by Drugs.com. Last updated on Sep 8, 2023.

Applies to nalidixic acid: oral suspension, oral tablet.

Serious side effects of nalidixic acid

Along with its needed effects, nalidixic acid 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 nalidixic acid:

More common

• skin rash

Less common

• blurred or decreased vision
• change in color vision
• confusion
• double vision
• halos around lights
• lightheadedness
• overbright appearance of lights
• restlessness
• tremor

Rare

• abdominal or stomach cramps or pain (severe)
• blistering, peeling, or loosening of the skin and mucous membranes
• bulging of fontanel (soft spot) on top of the head of an infant
• burning or tingling skin sensation
• changes in facial skin color
• chills
• convulsions (seizures)
• dark or amber urine
• diarrhea, watery and severe, which may also be bloody
• fever
• general feeling of discomfort or illness
• hallucinations (seeing, hearing, or feeling things that are not there)
• headache (severe)
• hives
• hoarseness
• increased frequency of breathing
• itching
• joint pain, stiffness, or swelling
• mood or other mental changes
• nausea or vomiting
• pale skin
• pale stools
• red skin lesions, often with a purple center
• shortness of breath
• sore throat
• sudden trouble in swallowing or breathing
• swelling of the face, mouth, hands, or feet
• unusual bleeding or bruising
• unusual tiredness or weakness
• visual changes
• yellow eyes or skin

Incidence not known

• black, tarry stools
• bone pain
• burning, numbness, tingling, or painful sensations
• chest pain
• cough
• difficulty with swallowing
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• lower back or side pain
• painful or difficult urination
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• redness of the skin
• sores, ulcers, or white spots on the lips or in the mouth
• swollen glands
• tightness in the chest
• unsteadiness or awkwardness
• weakness in the arms, hands, legs, or feet
• welts
• wheezing

Get emergency help immediately if any of the following symptoms of overdose occur while taking nalidixic acid:

Symptoms of overdose

• aggressive and violent behavior
• change in the ability to see colors, especially blue or yellow
• drowsiness
• headache
• loss of appetite
• rapid, deep breathing
• trouble with sleeping
• unable to sleep
• unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

Other side effects of nalidixic acid

Some side effects of nalidixic acid 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

• diarrhea
• dizziness
• feeling of constant movement of self or surroundings
• stomach pain
• weakness

Less common

• increased sensitivity of the skin to sunlight

Incidence not known

• difficulty with moving
• muscle pain or stiffness

For healthcare professionals

Applies to nalidixic acid: compounding powder, oral suspension, oral tablet.

Hypersensitivity

• Frequency not reported: Allergic reactions (including rash, pruritus, urticaria, angioedema, eosinophilia, arthralgia with joint stiffness and swelling, anaphylactoid reactions [including anaphylactic shock]), serious and occasionally fatal hypersensitivity (anaphylactoid) reactions^[Ref]

Dermatologic

• Frequency not reported: Rash, erythema multiforme, Stevens-Johnson syndrome, photosensitivity reactions (consisting of erythema and bullae on exposed skin surfaces), phototoxicity (moderate to severe)^[Ref]

Rash was reported most often.

Photosensitivity reactions appeared to be related to the amount of sun exposure rather than amount of drug taken. Most reactions were reported following intense sun exposure during the summer. Large bullae developed most commonly on the dorsum of the hands and feet. Photosensitivity reactions usually resolved 2 weeks to 2 months after drug discontinuation. In some cases, bullae continued to appear with additional sun exposure or with mild skin trauma for up to 3 months after discontinuation of nalidixic acid. Recurrence of bullae have been reported after 1 year.^[Ref]

Gastrointestinal

• Frequency not reported: Nausea, vomiting, abdominal pain, diarrhea, Clostridium difficile associated diarrhea^[Ref]

Nervous system

• Rare (less than 0.1%): Convulsions/seizures, sensory or sensorimotor axonal polyneuropathy affecting small and/or large axons (resulting in paresthesias, hypoesthesias, dysesthesias, weakness)
• Frequency not reported: Drowsiness, weakness, headache, dizziness, vertigo, peripheral neuropathy, paresthesia

Infants and children:

• Frequency not reported: Increased intracranial pressure with bulging anterior fontanel, papilledema, headache, 6th cranial nerve palsy^[Ref]

Brief convulsions were usually associated with excessive doses. In general, the convulsions were reported in patients with predisposing factors such as epilepsy or cerebral atherosclerosis.^[Ref]

Psychiatric

• Rare (less than 0.1%): Toxic psychosis, psychotic reactions (involving delirium, photophobia, paranoia, visual hallucinations)^[Ref]

Toxic psychosis was usually associated with excessive doses.

Psychotic reactions involving delirium, photophobia, paranoia, and visual hallucinations have rarely been reported with nalidixic acid. Seizures may also be involved and hyperglycemia was often present.^[Ref]

Musculoskeletal

• Frequency not reported: Arthralgias, myalgias, tendon disorders (including tendon rupture)^[Ref]

Ocular

• Rare (less than 0.1%): Reversible subjective visual disturbances without objective findings (including overbrightness of lights/photophobia, change in color perception, difficulty in focusing, decrease in visual acuity, double vision)^[Ref]

Visual disturbances usually resolved with dosage reduction or drug discontinuation.^[Ref]

Hematologic

• Rare (less than 0.1%): Thrombocytopenia, leukopenia, eosinophilia, hemolytic anemia (sometimes associated with glucose 6-phosphate deficiency)^[Ref]

Hemolytic anemia secondary to nalidixic acid most commonly occurred in patients with G6PD deficiency but was also reported in patients without this deficiency. Direct Coombs' tests were generally positive. Death from nalidixic acid induced hemolytic anemia has been reported.^[Ref]

Metabolic

• Rare (less than 0.1%): Metabolic acidosis, lactic acidosis^[Ref]

Metabolic acidosis has been reported in a few patients, generally after an overdose of nalidixic acid. Lactic acidosis resulting in death occurred in a diabetic woman.^[Ref]

Hepatic

• Rare (less than 0.1%): Cholestasis^[Ref]

Further information

Nalidixic acid side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

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