Severe worsening of hepatitis (rarely including death) has occurred when treatment with adefovir dipivoxil is stopped. When you are instructed to stop taking this medication, your doctor will monitor you closely for signs of worsening hepatitis. If you are instructed to stop taking this medication, be sure to keep all doctor and lab appointments after you stop taking this drug. Rarely, severe (sometimes fatal) liver and blood acid-base balance problems (lactic acidosis) have occurred in patients (especially if overweight) while using similar types of medication (nucleoside analogs such as didanosine or stavudine). Tell your doctor right away if you have unusual weakness/tiredness, dark urine, yellowing eyes/skin, stomach/abdominal pain, drowsiness, muscle aches/weakness, fast/difficult breathing, or fast/irregular heartbeat. In patients with kidney disease, adefovir dipivoxil can cause kidney problems. Tell your doctor right away if you develop signs of kidney problems such as a change in the amount of urine. If you get or have HIV infection that is not being treated with medication, adefovir dipivoxil may cause your HIV infection to become untreatable with the usual HIV drugs (development of HIV resistance). Talk to your doctor or pharmacist for more details.

Weakness, headache, fever, increased cough, nausea, vomiting, diarrhea, or gas may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: signs of kidney problems (such as change in the amount of urine). A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

A product that may interact with this drug is: cidofovir. Do not take products that contain tenofovir with this medication.