Didanosine resources

DRUG INFO
Didanosine

Drug Name: Didanosine

Indication: For treatment of Human immunovirus (HIV) infections

Pharmacology: Didanosine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Didanosine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated.

Mechanism Of Action: Didanosine (ddI) is metabolized intracellularly by a series of cellular enzymes to its active moiety, 2,3–dideoxyadenosine-5-triphosphate (ddA-TP), which inhibits HIV DNA polymerase (reverse transcriptase). Didanosine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA.

Drug Category: Anti-HIV Agents; Antimetabolites; Nucleoside and Nucleotide Reverse Transcriptase Inhibitors; ATC:J05AF02

Brand Names/Synonyms: 2'3'-DIDEOXYINOSINE; 2DI; CCRIS 805; DDI; DIDEOXYINOSINE; Ddi; Ddi, Didanosine; Didanosine; Didanosine [Usan:Ban:Inn]; Dideoxyinosine; Videx; Videx Ec; [Inn-Latin]; [Inn-Spanish]

Dosage Forms: CAPSULE (ENTERIC-COATED); POWDER FOR SOLUTION; TABLET

Absorption: Rapidly absorbed (bioavailability = 30-40%) with peak plasma concentrations appearing within 0.5 and 1.5 hrs.

Interactions: Coadministration of VIDEX with drugs that are known to cause pancreatitis may increase the risk of this toxicity (see WARNINGS) and should be done with extreme caution, only if other alternatives are not available, and only if clearly indicated. Neuropathy has occurred more frequently in patients with a history of neuropathy or neurotoxic drug therapy, including stavudine, and these patients may be at increased risk of neuropathy during VIDEX therapy (see ADVERSE REACTIONS). Allopurinol: The AUC of didanosine was increased about 4-fold when allopurinol at 300 mg/day was coadministered with a single 200-mg dose of VIDEX to two patients with renal impairment (CLcr=15 and 18 mL/min). The effects of allopurinol on didanosine pharmacokinetics in subjects with normal renal function are not known. Antacids: Concomitant administration of antacids containing magnesium or aluminum with VIDEX Chewable/Dispersible Buffered Tablets or Pediatric Powder for Oral Solution may potentiate adverse events associated with the antacid components. Drugs Whose Absorption Can Be Affected by the Level of Acidity in the Stomach: Drugs such as ketoconazole and itraconazole should be administered at least 2 hours prior to dosing with VIDEX. Ganciclovir: Administration of VIDEX 2 hours prior to or concurrent with oral ganciclovir was associated with a 111 (114)% increase in the steady-state AUC of didanosine (n = 12). A 21 (17)% decrease in the steady-state AUC of ganciclovir was observed when VIDEX was administered 2 hours prior to ganciclovir, but not when the two drugs were administered simultaneously (n = 12). Quinolone Antibiotics: VIDEX should be administered at least 2 hours after or 6 hours before dosing with ciprofloxacin because plasma concentrations of ciprofloxacin are decreased when administered with antacids containing magnesium, calcium, or aluminum. In eight HIV-infected patients, the steady-state AUC of ciprofloxacin was decreased an average of 26% (95% CI = 14%, 37%) when ciprofloxacin was administered 2 hours prior to a marketed chewable/dispersible tablet formulation of VIDEX. The AUC of ciprofloxacin was decreased an average of 15-fold in 12 healthy subjects given ciprofloxacin and didanosine-placebo tablets concurrently. In a single subject given one dose of ciprofloxacin 2 hours after a dose of didanosine-placebo tablets, a greater than 50% reduction in the AUC of ciprofloxacin was observed. Plasma concentrations of quinolone antibiotics are decreased when administered with antacids containing magnesium, calcium, or aluminum. The optimal dosing interval for coadministration with VIDEX should be determined by consulting the appropriate quinolone package insert. Interactions with Other Antiretroviral Drugs: Significant decreases in the AUC of delavirdine (20%) and indinavir (84%) occurred following simultaneous administration of these agents with VIDEX. To avoid this interaction, delavirdine or indinavir should be given 1 hour prior to dosing with VIDEX. The pharmacokinetics of nelfinavir are not altered to a clinically significant degree when it is administered with a light meal 1 hour after VIDEX.

Chemical IUPAC Name: 9-[5-(hydroxymethyl)tetrahydrofuran-2-yl]-3,9-dihydropurin-6-one

Chemical Formula: C10H12N4O3

Half Life: 1.5 +/- 0.4 hours

Drug Type: Approved Drug

# Accession No: APRD00240

CAS Registry Number: 69655-05-6

Didanosine News
(When available)

CROI: Tenofovir and kidney toxicity - low rates seen, but some ... 09 Feb 2006
Abstract #778. Crane H Didanosine and lower baseline body weight are associated with declining renal function among patients receiving tenofovir. ... - Aidsmap,

Simplified treatment regimens show promise in HIV-infected ... Feb 6, 2006
They treated the patients with a once-daily regimen of three anti-HIV drugs comprising ddI (didanosine, Videx / Videx EC), FTC (emtricitabine, Emtriva) and ... - Aidsmap,

Barr reports strong quarterly earnings Feb 8, 2006
...was largely attributable to Barr's introductions of its versions of desmopressin, used to treat bed wetting and frequent urination, and didanosine, an HIV drug ... - The Journal News.com,

Multi-component drug delivery system: An emerging trend Feb 8, 2006
3TC (Epivir), tenofovir (Viread), abacavir/lamivudine /zidovudine (Trizivir), lamivudine/zidovudine (Combivir), stavudine, d4T (Zerit), didanosine, ddI (Videx ... - Express Pharma Pulse,

Barr Reports Second Quarter Fiscal 2006 GAAP Earnings of $0.88 Per ... Feb 7, 2006
...increase is primarily related to strong sales of the Company's Desmopressin product that was launched in July 2005 and sales of its Didanosine product that was ... - PR Newswire (press release),

Bristol-Myers Squibb and Gilead Announce Data Supporting ... Jan 9, 2006
Drug interactions have been observed when didanosine, atazanaviror lopinavir/ritonavir is co-administered with Viread and doseadjustments may be necessary. ... - Finanzen.net,

Data Comparing Viread(R) and Emtriva(R) to Combivir(R) as Part of ... Jan 18, 2006
Drug interactions have been observed when didanosine, atazanavir, or lopinavir/ritonavir are co-administered with Viread, a component of Truvada, and dose ... - Genetic Engineering News,

Drug price reduction makes Aids manageable Jan 25, 2006
Since then, it has secured voluntary licenses from Bristol-Myers Squibb (for stavudine and didanosine), Boehringer Ingleheim (for nevirapine) and Merck Sharp & ... - iAfrica.com,

FDA Accepts for Filing Oscient Pharmaceuticals' Supplemental New ... Jan 20, 2006
Drug-drug interactions include probenicid, sucralfate, antacids containing aluminum or magnesium, iron, multivitamins containing metal cations, and didanosine. ... - Genetic Engineering News,

Increase ribavirin dose for better HCV treatment response in ...  Jan 18, 2006
...therapy. Exclusion criteria include psychiatric illness, alcohol abuse, ddI (didanosine, Videx / VidexEC) use, and cirrhosis. Around ... - Aidsmap, Macworld Conference & Expo 2006 Exhibitor Profiles  Jan 10, 2006
TMCnet Come visit our booth #107 to see brand new version 3.0 make its debut at the Show and meet the software developer in person. Company: Videx, Inc. ...

DELIVERING NEWS AND OPINION SINCE MAY 9, 2005  Dec 18, 2005
Huffington Post, The drug was ddI, an AIDS drug invented and patented by the US government and licensed to BMS, which it sells under the brand name of Videx. ...

Didanosine resources

DRUG INFO Didanosine

DRUG INFO
Didanosine