Didanosine (oral)

Overview

Didanosine is used, often in conjunction with other medicines, to treat HIV infection. It belongs to a class of medications known as nucleoside reverse transcriptase inhibitors, or NRTIs. While Didanosine does not cure the human immunodeficiency virus, it can decrease the possibility of developing AIDS (acquired immunodeficiency syndrome) and other HIV-related conditions such as cancer or serious infection.

It functions by reducing the amount of HIV present in the blood, and its use - along with lifestyle changes, such as practicing safer sex and avoiding sharing needles, can decrease the risk of transmitting HIV to other people.

During HIV infection, the virus multiplies within cells in the body. These newly-formed viruses are subsequently released from these cells where they are free to spread throughout the body, infecting other healthy cells. HIV targets new, uninfected cells which the body constantly produces. When producing new viruses, HIV must manufacture new DNA every time, and reverse transcriptase is the enzyme required by the virus to form new DNA. When Didanosine is taken, it is converted by the body to an active form of dideoxydenosine triphosphate. This active form is quite similar to a chemical which is required by HIV to produce new DNA. The HIV virus therefore begins to use dideoxydenosine triphosphate for the purposes of creating DNA, and the dideoxydenosine triphosphate interferes with the reverse transcriptase. While Didanosine doesn't kill the HIV virus, it prevents it from attacking healthy cells.

In some instances, Didanosine can also be used with other medicines to help avoid infection in healthcare workers or others who were accidentally exposed to the HIV virus. It can also be used 'œoff label' for a variety of other conditions, at the discretion of the prescribing doctor.

Didanosine was initially designed in 1975, and eventually became approved for use in the US in 1991. It is regarded by the World Health Organization as an essential medicine, on account of its relatively low cost to produce and efficacy in treating HIV infection.

Type Of Medicine

  • Nucleoside reverse transcriptase inhibitor

Conditions Treated

  • Human immunodeficiency virus

Side Effects

Along with its required effects, Didanosine can also cause unwanted side effects. The most commonly reported side effects by users undergoing treatment with this medicine include the following: nausea and vomiting, stomach pain, tingling/burning/numbness in the hands or feet, fevers, chills, shortness of breath, itching, skin rash, unusual bleeding or bruising, yellow eyes or skin, unusual tiredness or weakness, difficulty sleeping, irritability, restlessness and/or sore throat.

As the patient continues to take the medication as prescribed, the previously mentioned side effects should lessen. If any side effects persist over a prolonged period or appear to get worse, the patient is advised to follow this up with their doctor as soon as possible. In some instances, a healthcare professional or pharmacist may be able to advise on ways to alleviate certain symptoms of mild discomfort via treatment with over the counter or natural remedies. For example, a sore throat can be treated with cough medicine or lozenges.

Generally, the majority of patients only experience minimal side effects while taking Didanosine, if they experience any whatsoever. This medication is designed to treat the highly serious HIV infection, and most doctors agree that the benefits of controlling the virus far outweigh the risks of potentially experiencing unwanted side effects.

Other side effects experienced very rarely, albeit often enough to warrant mentioning, include the following:

  • Anxiety
  • Black or tarry stools
  • Abdominal discomfort
  • Bleeding cums
  • Bloating
  • Blindness
  • Blue-yellow color blindness
  • Blood in the stools or urine
  • Blurry vision
  • Changes in the color of the iris
  • Chest pain
  • Cold sweat
  • Clay-colored stools
  • Coma
  • Cool or pale skin
  • Constipation
  • Cough
  • Decrease in appetite
  • Depression
  • Decreased vision
  • Diarrhea
  • Difficulty swallowing
  • Difficult moving
  • Dry eyes
  • Dizziness
  • Dry mouth
  • Fast heartbeat
  • Shallow breathing
  • Eye pain
  • General feeling of discomfort
  • Flushed or dry skin
  • Headache
  • Fruit-like breath odor
  • Hives
  • Increased appetite
  • Increased level of urination
  • Indigestion
  • Increased thirst
  • Light-colored stools
  • Muscle cramps, aches or pains
  • Nightmares
  • Pains in the stomach which radiate to the back
  • Pinpoint spots on skin
  • Swelling of the eyelids, face, lips and/or tongue
  • Shakiness
  • Slurred speech
  • Sleepiness
  • Ulcers, sores or white spots in the mouth or on the lips
  • Swollen glands
  • Sweating
  • Swollen joints
  • Difficult breathing with exertion
  • Unexplained loss of weight
  • Stomach ache
  • Unsteadiness or awkwardness
  • Weakness in the hands, arms, legs or feet
  • Acidic stomach
  • Excess gas
  • A feeling of fullness
  • Indigestion
  • Accumulation of body fat
  • Heartburn
  • Belching

Patients who experience any of these conditions to the point of discomfort should contact their healthcare provider as soon as is practical.

Because Didanosine can affect the motor skills and vision, patients are advised against driving or operating any heavy machinery until it has been observed that these particular side effects are not detrimental to the patient's ability to control a vehicle. This is to protect both the patient and other road users from hazards which may arise as a result of loss of control due to taking Didanosine.

Dosage

As with all medicines, it is incredibly important to only take Didanosine as prescribed by a qualified doctor. This means that patients must avoid taking any more of the drug than they are advised to ' both in terms of frequency and dose size. In addition to this, patients should cease treatment with this medicine if advised to do so by a physician, even if they still have a supply of the drug remaining.

Didanosine is available as an extended release capsule or an oral solution. The prescribing doctor will decide on which course of treatment is best for the patient. It is best taken on an empty stomach, approximately 30 minutes before eating. Alternatively, the patient can take Didanosine two hours after eating. The extended release capsules are typically taken once a day, whereas the liquid solution is administered twice a day. For the best results, patients are advised to take Didanosine at the same time every day. Patients are also advised to follow any directions their doctor may have given them, and to read all of the information provided with the medication.

Patients who are receiving treatment with the extended release capsules should swallow them whole, with a glass of water. Didanosine extended release capsules should not be chewed, crushed, broken or dissolved in liquid. Patients who are unable to swallow the capsules whole should inform their doctor.

Patients who are receiving treatment with Didanosine liquid solution should shake the product well before use, in order to ensure that the medicine is mixed evenly, as contents may settle. A measuring spoon or cup should be used to ensure the correct amount of liquid is administered for each dose, although patients are advised against using a regular household spoon for dose measurement as this may result in inaccurate dosage.

While the manufacturer provides dosage instructions for Didanosine on the literature which ships with the medication, it should be reiterated that these recommendations are for guideline purposes only, and can be altered by the prescribing physician. A doctor will take various factors into account when determining dose size, including the age, height, weight and condition of the patient.

Usual adult dose for HIV infection:

  • Patients taking the delayed release capsules who weigh less than 60kg should take 250mg of Didanosine, orally, once a day.
  • Patients taking the delayed release capsules who weigh in excess of 60kg should take 400mg of Didanosine, orally, once a day.
  • Patients taking Didanosine oral solution who weigh less than 60kg should take 125mg of the liquid, orally, twice a day. Alternatively, patients can take 250mg of the liquid once per day.
  • Patients taking Didaonsine oral solution who weigh more than 60kg should take 200mg of the liquid, orally, twice a day. Alternatively, they can take 400mg of the liquid once per day.

Usual pediatric dose for HIV infection:

  • Young patients receiving treatment with the delayed release capsules who weigh up to 25kg should take 200mg Didanosine, orally, once a day.
  • Young patients receiving treatment with the delayed release capsules who weigh between 25kg and 60kg should take 250mg once a day.
  • Young patients weighing over 60kg should proceed with the adult dosage.

Delayed release Didanosine capsules are recommended in children above the age of six. Infants and newborn babies are more likely to be treated with the liquid solution, as it is easier to administer.

  • Patients aged between 2 weeks and 8 months should receive 100mg Didanosine liquid solution, orally, twice a day.
  • Patients aged older than 8 months should receive 120mg Didanosine liquid solution, orally, twice a day.

Renal dose adjustments:

Patients with kidney issues may require a dose adjustment so that the drug remains safe to take, dependent on their creatinine clearance calculations as follows:

  • Patients with CrCl of 30 to 59 mL/min who weigh less than 60kg should take 125mg Didanosine, orally, once a day.
  • Patients with CrCl of 30 to 59 mL/min who weigh more than 60kg should take 200mg Didanosine, orally, once a day.
  • Patients with CrCl of 10 to 29 mL/min who weigh less than 60kg should take 125mg Didanosine, orally, once a day.
  • Patients with CrCl of 10 to 29 mL/min who weigh more than 60kg should take 125mg Didanosine, orally, once a day.

Treatment with Didanosine is not recommended in patients with CrCl of less than 10mL/min. In this instance, a doctor should be able to prescribe an alternative course of treatment.

If the patient misses a dose, he or she is advised against taking a double dose to make up for the missed dose. If the patient notices they have missed a dose shortly after the scheduled dose time, they may take the missed dose and then continue with the schedule as normal. If it is nearer to the time for the next scheduled dose, the patient should simply omit the missed dose and take the next dose as standard, before continuing with the dose scale as prescribed by their doctor.

In the event of an overdose, the patient is advised to contact their local poison control center on 1800-1222-222 or the emergency services on 911. Alternatively, the patient should make their way to their local ER if they are in close enough proximity to it. Symptoms of overdose include difficulty breathing, extremely slow or fast heartbeat, loss of co-ordination, seizures and/or loss of consciousness.

Interactions

All medications have the potential to interact with other chemicals or drugs within the human body. These interactions can potentially change the effects of each medication, causing one or more of them to become ineffective in treating the condition they were originally prescribed to combat. In other instances, interactions can cause dangerous and even fatal side effects. Because of these risks, patients are advised to keep a full, detailed list of all medications they are currently taking. This extends to over the counter remedies, vitamins, herbal supplements and complimentary medicines as well as prescribed drugs.

Below is a list of medicines known to have interacted negatively with Didanosine. Patients who are already taking one or more of these medicines should notify their doctor or healthcare provider prior to undergoing treatment with Didanosine:

  • Zidovudine
  • Zalcitabine
  • Zafirlukast
  • Vinorelbine
  • Vincristine Liposome
  • Vincristine
  • Vinblastine
  • Valganciclovir
  • Trovafloxacin
  • Triazolam
  • Trandolapril/Verapamil
  • Trandolapril
  • Trabectedin
  • Tocilizumab
  • Tipranavir
  • Tinidazole
  • Thyroid Desiccated
  • Thioguanine
  • Thalidomide
  • Tetracycline
  • Teriflunomide
  • Teniposide
  • Temazepam
  • Telbivudine
  • Stavudine
  • Sparfloxacin
  • Sodium Thiosalicylate
  • Sodium Salicylate
  • Simvastatin/Sitagliptin
  • Simvastatin
  • Secnidazole
  • Salsalate
  • Rosuvastatin
  • Ritonavir
  • Rifampin
  • Ribavirin
  • Red Yeast Rice
  • Ranitidine Bismuth Citrate
  • Ranitidine
  • Ramipril
  • Quinapril
  • Quazepam
  • Pravastatin
  • Ponatinib
  • Pomalidomide
  • Pitavastatin
  • Perindopril
  • Pentamidine
  • Peginterferon Beta-1A
  • Peginterferon Alfa-2B
  • Peginterferon Alfa-2A
  • Paclitaxel Protein-Bound
  • Paclitaxel
  • Oxytetracycline/Phenazopyridine/Sulfamethizole
  • Oxytetracycline
  • Oxazepam
  • Oxaliplatin
  • Orlistat
  • Ombitasvir/Paritaprevir/Ritonavir
  • Ofloxacin
  • Norfloxacin
  • Nitrofurantoin
  • Niacin/Simvastatin
  • Nelfinavir
  • Nelarabine
  • Naltrexone/Oxycodone
  • Naltrexone
  • Nalidixic Acid
  • Mycophenolic Acid
  • Mycophenolate Mofetil
  • Moxifloxacin
  • Morphine/Naltrexone
  • Moexipril
  • Mipomersen
  • Minocycline
  • Midazolam
  • Metronidazole
  • Methotrexate
  • Methamphetamine
  • Methadone
  • Magnesium Salicylate/Phenyltoloxamine
  • Magnesium Salicylate
  • Lovastatin/Niacin
  • Lovastatin
  • Lorazepam
  • Lopinavir/Ritonavir
  • Lomitapide
  • Lomefloxacin
  • Lisinopril
  • Lisdexamfetamine
  • Liotrix
  • Liothyronine
  • Linezolid
  • Lidocaine/Oxytetracycline
  • Levothyroxine
  • Levofloxacin
  • Levodopa
  • Leflunomide
  • Lamivudine/Zidovudine
  • Ketoconazole
  • Ixazomib
  • Ixabepilone
  • Itraconazole
  • Isoniazid/Rifampin
  • Isoniazid/Pyrazinamide/Rifampin
  • Isoniazid
  • Ipilimumab
  • Iodoquinol
  • Interferon Beta-1B
  • Interferon Beta-1A
  • Interferon Alfa-N1
  • Interferon Alfacon-1
  • Interferon Alfa-2B/Ribavirin
  • Interferon Alfa-2B
  • Interferon Alfa-2A
  • Infliximab
  • Indinavir
  • Idelalisib
  • Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate/Sodium Biphosphate
  • Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate
  • Hydroxyurea
  • Hydroxychloroquine
  • Hydrochlorothiazide/Quinapril
  • Hydrochlorothiazide/Moexipril
  • Hydrochlorothiazide/Lisinopril
  • Hydralazine/Isosorbide Dinitrate
  • Hydralazine/Hydrochlorothiazide/Reserpine
  • Hydralazine/Hydrochlorothiazide
  • Hydralazine
  • Halazepam
  • Grepafloxacin
  • Golimumab
  • Gold Sodium Thiomalate
  • Gemifloxacin
  • Gatifloxacin
  • Ganciclovir
  • Fosinopril/Hydrochlorothiazide
  • Fosinopril
  • Fluvastatin
  • Flurazepam
  • Fludarabine
  • Ezetimibe/Simvastatin
  • Etravirine
  • Etoposide
  • Ethionamide
  • Ethambutol
  • Etanercept
  • Estazolam
  • Eribulin
  • Epirubicin
  • Enoxacin
  • Enalapril/Hydrochlorothiazide
  • Enalapril/Felodipine
  • Emtricitabine/Nelfinavir/Tenofovir
  • Emtricitabine/Lopinavir/Ritonavir/Tenofovir
  • Elvitegravir
  • Elotuzumab
  • Efavirenz/Emtricitabine/Tenofovir
  • Efavirenz
  • Doxycycline/Salicylic Acid Topical
  • Doxycycline/Omega-3 Polyunsaturated Fatty Acids
  • Doxycycline
  • Dolutegravir
  • Docetaxel
  • Disulfiram
  • Diphenhydramine/Magnesium Salicylate
  • Diltiazem/Enalapril
  • Diazepam
  • Dextroamphetamine
  • Demeclocycline
  • Delavirdine
  • Delafloxacin
  • Dasatinib
  • Dasabuvir/Ombitasvir/Paritaprevir/Ritonavir
  • Darunavir
  • Dapsone
  • Crizotinib
  • Colchicine/Probenecid
  • Colchicine
  • Cobicistat/Darunavir
  • Cobicistat
  • Clorazepate
  • Clonazepam
  • Clofarabine
  • Clobazam
  • Cladribine
  • Cisplatin
  • Ciprofloxacin
  • Cinoxacin
  • Choline Salicylate/Magnesium Salicylate
  • Choline Salicylate
  • Chloroquine
  • Chlordiazepoxide/Methscopolamine
  • Chlordiazepoxide/Clidinium
  • Chlordiazepoxide
  • Chloramphenicol
  • Certolizumab
  • Cerivastatin
  • Cefuroxime
  • Cefpodoxime
  • Cefditoren
  • Carfilzomib
  • Carboplatin
  • Carbidopa/Levodopa
  • Carbidopa/Entacapone/Levodopa
  • Captopril/Hydrochlorothiazide
  • Captopril
  • Caffeine/Pheniramine/Phenylephrine/Sodium Citrate/Sodium Salicylate
  • Caffeine/Magnesium Salicylate
  • Cabazitaxel
  • Bupropion/Naltrexone
  • Brentuximab
  • Bortezomib
  • Black Cohosh
  • Bismuth Subsalicylate/Metronidazole/Tetracycline
  • Bismuth Subcitrate Potassium/Metronidazole/Tetracycline
  • Bexarotene
  • Benzphetamine
  • Benzoic Acid/Methenamine/Sodium Salicylate
  • Benzoic Acid/Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate
  • Benznidazole
  • Benazepril/Hydrochlorothiazide
  • Benazepril
  • Bedaquiline
  • Bacampicillin
  • Azithromycin/Trovafloxacin
  • Aurothioglucose
  • Auranofin
  • Atovaquone/Proguanil
  • Atovaquone
  • Atorvastatin/Ezetimibe
  • Atorvastatin
  • Atazanavir/Cobicistat
  • Atazanavir
  • Aspirin/Pseudoephedrine
  • Aspirin/Pravastatin
  • Aspirin/Phenyltoloxamine
  • Aspirin/Pentazocine
  • Aspirin/Oxycodone
  • Aspirin/Omeprazole
  • Aspirin/Methocarbamol
  • Aspirin/Meprobamate
  • Aspirin/Hydrocodone
  • Aspirin/Dipyridamole
  • Aspirin/Diphenhydramine/Phenylpropanolamine
  • Aspirin/Diphenhydramine
  • Aspirin/Codeine
  • Aspirin/Citric Acid/Sodium Bicarbonate
  • Aspirin/Chlorpheniramine/Phenylpropanolamine
  • Aspirin/Chlorpheniramine/Phenylephrine
  • Aspirin/Chlorpheniramine/Dextromethorphan/Phenylpropanolamine
  • Aspirin/Chlorpheniramine/Dextromethorphan
  • Aspirin/Carisoprodol/Codeine
  • Aspirin/Carisoprodol
  • Aspirin/Calcium Carbonate
  • Aspirin/Caffeine/Salicylamide
  • Aspirin/Caffeine/Propoxyphene
  • Aspirin/Caffeine/Orphenadrine
  • Aspirin/Caffeine/Dihydrocodeine
  • Aspirin/Caffeine
  • Aspirin/Butalbital/Caffeine/Codeine
  • Aspirin/Butalbital/Caffeine
  • Aspirin/Butalbital
  • Aspirin/Brompheniramine/Dextromethorphan/Phenylpropanolamine
  • Aspirin
  • Amprenavir
  • Amphetamine/Dextroamphetamine
  • Amphetamine
  • Amlodipine/Perindopril
  • Amlodipine/Benazepril
  • Amlodipine/Atorvastatin
  • Amitriptyline/Chlordiazepoxide
  • Amiodarone
  • Aluminum Hydroxide/Aspirin/Calcium Carbonate/Magnesium Hydroxide
  • Alprazolam
  • Allopurinol/Lesinurad
  • Allopurinol
  • Ado-Trastuzumab Emtansine
  • Adalimumab
  • Acetaminophen/Magnesium Salicylate/Pamabrom
  • Acetaminophen/Magnesium Salicylate
  • Acetaminophen/Caffeine/Magnesium Salicylate/Phenyltoloxamine
  • Acetaminophen/Caffeine/Magnesium Salicylate
  • Acetaminophen/Aspirin/Phenylpropanolamine
  • Acetaminophen/Aspirin/Diphenhydramine
  • Acetaminophen/Aspirin/Caffeine/Salicylamide
  • Acetaminophen/Aspirin/Caffeine
  • Acetaminophen/Aspirin
  • Acetaminophen/Aluminum Hydroxide/Aspirin/Caffeine/Magnesium Hydroxide
  • Abacavir/Lamivudine/Zidovudine
  • Abacavir/Dolutegravir/Lamivudine

Warnings

Didanosine can potentially cause a serious condition known as lactic acidosis. Patients are advised to get emergency medical help if they develop symptoms of this condition, which include muscle pain, a cold feeling in the legs or arms, difficulty breathing, nausea, vomiting, uneven hear rate, dizziness or a feeling of unusual weakness or tiredness. Women and/or patients who are overweight are more likely to experience this condition, and those who have lived with HIV or AIDS for a long time may be more susceptible to it. Patients who fit into these groups are advised to consult their doctor.

This medicine can also potentially have serious or even life-threatening effects on the pancreas or liver. Patients should call a doctor immediately if they notice severe pain in the upper stomach, a fast heart rate, loss or appetite, dark urine and/or jaundice (yellow skin or eyes).

Patients who have ever experienced an allergic reaction to foods, substances or medicines in the past should inform their doctor of the symptoms they experienced and the nature of their allergy. This is because Didanosine may contain active or inactive ingredients which could potentially cause allergic reactions in some patients.

Didanosine may not be safe for patients with the following conditions:

  • Kidney disease
  • Liver disease
  • Pancreatitis
  • Raynaud's syndrome
  • Alcoholism

Alcohol should be completely avoided by patients undergoing treatment with Didaonsine. This is because alcohol could increase the risk of pain and swelling of the pancreas, or could damage the liver which may already be under strain due to the course of this medication or other medicines used in conjunction with Didanosine to treat and control HIV.

Pregnant women are advised against taking Didanosine in conjunction with Stavudine. This is because the two medicines combined have a propensity to increase lactic acidosis or liver conditions, both of which can be incredibly dangerous during pregnancy, both to the fetus and the expectant mother. A doctor should be able to prescribe an alternative course of treatment under such circumstances.

Because HIV can be passed to a fetus during pregnancy, HIV-positive expectant mothers are advised to take all of their medicines as directed by a doctor to control the infection. Didanosine can be excreted into breast milk 'however, as the HIV virus can be passed to an infant via breast milk, mothers are advised to avoid breastfeeding altogether if they have HIV, even if the baby is born with the virus.

Storage

Didanosine extended release capsules should be kept in a tightly closed container, preferably the one the tablets were shipped in, at room temperature (15C to 30C). Bottles of Didanosine oral solution should be stored in a refrigerator, in a tightly closed container, and at a temperature between 2C and 8C. Any of the liquid solution remaining after 30 days should be disposed of in a safe and hygienic manner, in accordance with state law.

Patients are advised to avoid using Didanosine if the original seal over the container is missing or broken. Unwanted, unused or expired medicines which need to be discarded should be done so under FDA guidelines on medication disposal. Many pharmacies offer 'œtake back'schemes where they will recycle or destroy unwanted medicines for free. The patient should contact their pharmacist or local waste disposal department for further information.

Didanosine should be kept out of sight and reach of children.

Summary

While Didanosine is greatly beneficial to patients suffering from human immunodeficiency syndrome, it can also pose a risk to those who do not communicate effectively with their healthcare providers. As a treatment designed to stop HIV from spreading throughout the body, Didanosine converts to an enzyme which the virus mistakes for healthy cells, but it can also cause a variety of unwanted side effects which can impair the day-to-day functioning of the patient and potentially create dangerous situations unless the correct precautions are taken.

For these reasons, it is imperative that the patient is upfront about their medical history, providing as much information as possible on any lifestyle habits which may affect treatment (such as intravenous drug use or regular unsafe sex). There are hundreds of medicines which could interact with Didanosine, which is why it is in the best interests of the patient to be honest with their healthcare provider.

When taken correctly, Didanosine can prevent the HIV virus from spreading throughout the body. While there is no known cure for HIV, Didanosine can stop the spread of the disease and help in reducing its levels throughout the body to near-negligible amounts, allowing the patient to enjoy a much greater quality of life. In some cases, the symptoms of the disease can even be reduced to the level where the patient feels no adverse effects at all, allowing them to live almost as if they do not have the condition. To achieve these results, the patient and doctor need to work together to ascertain the correct dosage and frequency of use.