How does this medication work? What will it do for me?
Didanosine belongs to the class of medications called nucleoside reverse transcriptase inhibitors (NRTIs). Didanosine is used in combination with other medications to treat the infection caused by the human immunodeficiency virus (HIV). HIV is the virus responsible for acquired immune deficiency syndrome (AIDS). HIV infection destroys CD4 (T) cells, which are important to the immune system. The immune system helps fight infections.
Reverse transcriptase is a part of (HIV) required to infect cells and make more virus. Didanosine prevents reverse transcriptase from working properly.
Didanosine does not cure AIDS and does not prevent it from being spread to others. It does help to slow down the progression of the disease. This may help to delay the development of problems related to AIDS or HIV disease.
Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
What form(s) does this medication come in?
Videx® chewable tablets and pediatric solution are no longer available in Canada.
Each white, opaque, enteric-coated beadlet capsule, printed in tan with "BMS 125 mg" and "6671", contains didanosine 125 mg. Nonmedicinal ingredients: carboxymethylcellulose sodium, diethyl phthalate, methacrylic acid copolymer, sodium hydroxide, sodium starch glycolate, and talc; capsule shell: gelatin, sodium lauryl sulfate, and titanium dioxide. Capsules are imprinted with edible ink.
Each white, opaque, enteric-coated beadlet capsule, printed in green with "BMS 200 mg" and "6672", contains didanosine 200 mg. Nonmedicinal ingredients: carboxymethylcellulose sodium, diethyl phthalate, methacrylic acid copolymer, sodium hydroxide, sodium starch glycolate, and talc; capsule shell: gelatin, sodium lauryl sulfate, and titanium dioxide. Capsules are imprinted with edible ink.
Each white, opaque, enteric-coated beadlet capsule, printed in blue with "BMS 250 mg" and "6673", contains didanosine 250 mg. Nonmedicinal ingredients: carboxymethylcellulose sodium, diethyl phthalate, methacrylic acid copolymer, sodium hydroxide, sodium starch glycolate, and talc; capsule shell: gelatin, sodium lauryl sulfate, and titanium dioxide. Capsules are imprinted with edible ink.
Each white, opaque, enteric-coated beadlet capsule, printed in red with "BMS 400 mg" and "6674", contains didanosine 400 mg. Nonmedicinal ingredients: carboxymethylcellulose sodium, diethyl phthalate, methacrylic acid copolymer, sodium hydroxide, sodium starch glycolate, and talc; capsule shell: gelatin, sodium lauryl sulfate, and titanium dioxide. Capsules are imprinted with edible ink.
How should I use this medication?
The recommended adult dose of didanosine is based on body weight. People weighing 60 kg and over should be taking 400 mg once daily. People weighing less than 60 kg should be taking 250 mg once daily.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
Didanosine should be taken on an empty stomach (at least 1.5 hours before or 2 hours after eating) since food appears to reduce the amount of medication that gets absorbed into the bloodstream. It should not be taken with acidic fruit juices, as the acid in these juices can reduce the amount of medication available to be absorbed by the body.
This medication should be swallowed whole, not chewed or crushed.
It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, away from heat, direct light, and moisture. Keep it out of the reach of children.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not take didanosine if you are allergic to didanosine or any ingredient of the medication.
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- dry eyes
- dryness of mouth
- loss of appetite
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- abdominal pain
- fever and chills
- increased fat on the upper back, neck, breasts, and around the trunk; and loss of fat from the legs, arms, and face
- muscle aches
- signs of anemia (low red blood cells; e.g., pale skin, unusual tiredness or weakness)
- signs of bleeding, e.g.:
- blood in stools
- blood in urine
- bloody nose
- coughing blood
- cuts that don't stop bleeding
- signs of diabetes, e.g.:
- fruity smell to the breath
- increased thirst
- increased urination
- wounds that don't heal
- signs of infections, e.g.:
- fever or chills
- prolonged dizziness
- severe diarrhea
- shortness of breath
- stiff neck
- weight loss
- signs of liver problems, e.g.:
- dark urine
- loss of appetite
- pale stools
- weight loss
- yellowing of the skin or whites of the eyes
- tingling, burning, or numbness and pain in the hands or feet
- vision changes
Stop taking the medication and seek immediate medical attention if any of the following occur:
- signs of lactic acidosis, e.g.:
- abdominal pain
- increased breathing rate
- rapid heart rate
- unusual tiredness
- signs of pancreatitis, e.g.:
- abdominal pain on the upper left side
- back pain
- rapid heartbeat
- swollen abdomen
- signs of a serious allergic reaction, e.g.:
- abdominal cramps
- difficulty breathing
- nausea and vomiting
- swelling of the face and throat
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.
Fat redistribution: Over time, this medication may change how fat is distributed in your body and may change your body shape. You may notice increased fat in the upper back and neck, breast, around the back, chest, and stomach area; or loss of fat from the legs, arms, and face. The long-term effects of this are not known.
Immune reconstitution syndrome: This medication may cause immune reconstitution syndrome, where signs and symptoms of inflammation from previous infections appear. These symptoms occur soon after starting anti-HIV medication and can vary. They are thought to occur as a result of the immune system improving and being able to fight infections that have been present without symptoms (such as pneumonia, herpes, or tuberculosis). Report any new symptoms to your doctor as soon as possible.
Kidney function: Didanosine is removed from the body by the kidneys. Decreased kidney function may cause an increase in side effects due to an increased amount of medication in the body.
If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. People with severely reduced kidney function should not take this medication.
Lactic acidosis and enlarged fatty liver: Didanosine can cause a rare but serious condition called lactic acidosis (build-up of lactic acid in the blood) together with an enlarged liver. This tends to occur more often in women, especially if they are overweight. If you experience any of the following symptoms, call your doctor immediately:
- abdominal pain, swelling, or bloating
- feeling unwell
- shortness of breath
- weight loss
Your doctor will monitor your liver function periodically by ordering laboratory tests.
Liver function: People with liver disease or reduced liver function appear to have an increased risk of additional liver damage due to taking didanosine. If you have liver disease or decreased liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver failure has occurred in people taking didanosine who have had no previous liver problems. If you experience symptoms of liver problems (e.g., abdominal pain, persistent vomiting, feeling unwell, fever, itching, yellowing of the skin and eyes, dark urine), contact your doctor immediately.
Pancreatitis (inflammation of the pancreas): Didanosine may cause or worsen pancreatitis. If you have a history of or are at risk for developing pancreatitis, you should be closely monitored by your doctor while taking this medication. If you develop signs of pancreatitis (e.g., upper left abdominal pain, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen), contact your doctor.
Peripheral neuropathy: Didanosine may cause numbness, tingling or pain in the feet or hands. This is known as peripheral neuropathy, a nervous system complication of both the disease and this medication. If you experience these symptoms, contact your doctor as soon as possible.
Portal hypertension: Portal hypertension (increased blood pressure in the large vein of the liver) may occur with normal use of didanosine. Your doctor will order blood tests to check for early signs of this complication. If you experience vomiting blood or an unusual increase in the size of your abdomen, contact your doctor as soon as possible.
Pregnancy: Adequate studies of the use of this medication by pregnant women are not available. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if didanosine passes into breast milk. Women who have HIV infection are cautioned against breast-feeding because of the risk of passing HIV to a baby who does not have the infection.
Children: The safety and effectiveness of this medication have not been established for children.
Seniors: Seniors have an increased risk of side effects with didanosine. They may require lower doses and closer monitoring by the doctor.
What other drugs could interact with this medication?
There may be an interaction between didanosine and any of the following:
- "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole)
- quinolone antibiotics (e.g., ciprofloxacin, moxifloxacin, norfloxacin)
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.