Note: This document contains side effect information about etidronate. Some dosage forms listed on this page may not apply to the brand name Didronel.

Applies to etidronate: oral tablet.

Serious side effects of Didronel

Along with its needed effects, etidronate (the active ingredient contained in Didronel) 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 etidronate:

More common

• Bone pain or tenderness (increased, continuing, or returning—in patients with Paget's disease)

Less common

• Bone fractures, especially of the thigh bone

Rare

• Abdominal or stomach pain or burning
• bloody, black, or tarry stools
• chest pain
• chills
• cough or hoarseness
• fever
• general feeling of tiredness or weakness
• hives
• lower back or side pain
• noisy breathing
• painful or difficult urination
• pale skin
• skin rash or itching
• sore throat
• sores, ulcers, or white spots on the lips or inside the mouth
• swelling of the arms, legs, face, lips, tongue, or throat
• swollen glands
• tightness in the chest
• unusual bleeding or bruising

Incidence not known

• Blistering, peeling, loosening of the skin
• bone, joint, or muscle pain that is severe and occasionally disabling
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• difficulty in moving
• difficulty in swallowing
• discouragement
• feeling sad or empty
• heartburn
• heavy jaw feeling
• irritability
• lack of appetite
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• loosening of a tooth
• loss of interest or pleasure
• loss of memory
• pain or burning in the throat
• pain, swelling, or numbness in the mouth or jaw
• problems with memory
• rash with flat lesions or small raised lesions on the skin
• red irritated eyes
• red skin lesions, often with a purple center
• redness or discoloration of the skin
• seeing, hearing, or feeling things that are not there
• trouble concentrating
• trouble sleeping
• unusual tiredness or weakness
• vomiting

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

Symptoms of overdose

• Abdominal or stomach cramps
• confusion
• convulsions
• difficulty in breathing
• irregular heartbeats
• mood or mental changes
• muscle cramps in the hands, arms, feet, legs, or face
• numbness and tingling around the mouth, fingertips, or feet
• shortness of breath
• tremor

Other side effects of Didronel

Some side effects of etidronate 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
• nausea

Incidence not known

• Burning feeling in the chest or stomach
• hair loss, thinning of hair
• headache
• indigestion
• leg cramps
• stomach upset
• tenderness in the stomach area

For Healthcare Professionals

Applies to etidronate: intravenous solution, oral tablet.

Gastrointestinal

Gastrointestinal side effects are more common with higher doses (10 to 20 mg/kg) and may be alleviated by dividing the daily dose.^[Ref]

Common (1% to 10%): Diarrhea, nausea

Rare (less than 0.1%): Burning of the tongue

Frequency not reported: Exacerbation of peptic ulcer disease including perforation in a few patients, gastritis

Postmarketing reports: Esophagitis; glossitis, duodenal ulcer^[Ref]

Dermatologic

Rare (less than 0.1%): Erythema multiforme, alopecia

Frequency not reported: Angioedema, follicular eruption, macular rash, maculopapular rash, pruritus, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria^[Ref]

Hypersensitivity

Rare (less than 0.1%): Hypersensitivity reactions, including angioedema, urticaria, rash, pruritus^[Ref]

Musculoskeletal

Uncommon (0.1% to 1%): Arthropathies (arthralgia and arthritis)

Rare (less than 0.1%): Atypical subtrochanteric and diaphyseal femoral fractures

Frequency not reported: Osteonecrosis of the jaw (ONJ), leg cramps, increased or recurrent bone pain at pagetic sites and onset of pain at previously asymptomatic sites

Postmarketing reports: Bone fracture, osteomalacia^[Ref]

At higher doses the incidence of increased or recurrent bone pain at pagetic sites and/or onset of pain at previously asymptomatic sites rise. When therapy continues, pain resolves in some patients but persists in others.^[Ref]

Psychiatric

Rare (less than 0.1%): Confusion

Postmarketing reports: Depression, hallucination^[Ref]

Nervous system

Rare (less than 0.1%): Paresthesia, peripheral neuropathy

Frequency not reported: Headache

Postmarketing reports: Neuropsychiatric events including amnesia^[Ref]

Respiratory

Rare (less than 0.1%): Exacerbation of asthma^[Ref]

Hematologic

Rare (less than 0.1%): Leukopenia, agranulocytosis pancytopenia^[Ref]