AccessPak for HIV PEP Expanded with Kaletra and Videx

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Talk to your doctor before using didanosine together with tenofovir. Combining these medications may increase the blood levels and effects of didanosine. This can increase the risk of serious side effects such as pancreatitis (inflammation of the pancreas), lactic acidosis (the buildup of lactic acid in the body), and peripheral neuropathy (nerve damage, particularly in the hands and feet). You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if you experience nausea, vomiting, abdominal pain, fatigue, weight loss, loss of appetite, shortness of breath, muscle weakness, or numbness, tingling, or pain in the hands and feet. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

ADJUST DOSE: Coadministration with tenofovir disoproxil fumarate may increase the plasma concentrations and toxicity of didanosine (ddI). The mechanism of interaction has not been established but may involve competitive inhibition of didanosine renal tubular secretion into the urine via human organic anion transporter 1 (hOAT1). In 14 healthy volunteers, tenofovir DF (300 mg/day) increased the steady-state peak plasma concentration (Cmax) and systemic exposure (AUC) of ddI (buffered tablets 250 or 400 mg/day, depending on weight) by an average of 28% and 44%, respectively, while ddI had no effect on the pharmacokinetics of tenofovir. Similar findings have been reported in pharmacokinetic studies using enteric-coated ddI, and the interaction occurred whether the drugs were administered simultaneously or 1 to 2 hours apart and with or without a light meal. Clinically, the interaction has been suspected in several cases of pancreatitis and lactic acidosis, some resulting in death, in patients who have previously tolerated ddI without tenofovir DF. Likewise, a retrospective analysis of 575 patients from an HIV clinic within a 2-year period found a higher incidence of pancreatitis in patients receiving ddI plus tenofovir DF than in those receiving ddI without tenofovir DF or tenofovir DF without ddI (2.7% vs. 0.5% and 0%, respectively). The interaction has also been associated with several cases of acute tubular necrosis and Fanconi's syndrome. In addition, compromised immunologic response and even deleterious effects on CD4 and CD8 cell counts have been reported with the combination. In one study, more than half of the 302 patients receiving regimens containing standard-dose ddI and tenofovir DF experienced a decline of more than 100 CD4 cells/mm3 (up to 30% had a decrease of more than 200 cells/mm3) at 48 weeks follow-up despite the maintenance of viral suppression, whereas patients receiving tenofovir DF without ddI or vice versa did not. Subsequent dose reduction of ddI led to a decrease in ddI plasma levels and a recovery of CD4, CD8, and total lymphocyte counts in a subgroup of the patients. A high rate of early virological failure has also been reported in patients receiving tenofovir DF and ddI with a nucleoside or nonnucleoside reverse transcriptase inhibitor.

MANAGEMENT: Due to reports of poor immunologic response and high rate of early virological failure, some experts do not recommend the coadministration of tenofovir DF and ddI within any antiretroviral regimen, particularly in patients with high viral load and low CD4 cell count. If the combination is prescribed, patients should be monitored closely for long-term ddI adverse effects such as pancreatitis, peripheral neuropathy, lactic acidosis, and nephropathy. In adults with normal renal function weighing more than 60 kg, the ddI dosage should be reduced from 400 to 250 mg/day when prescribed with tenofovir DF. For patients under 60 kg, the ddI dosage should be reduced from 250 mg to 200 mg once daily. During coadministration, the drugs may be taken on an empty stomach or with a light meal (less than 400 kcal, less than 20% fat) if the enteric-coated formulation of ddI is used. The drugs should be taken on an empty stomach if ddI is administered as one of the buffered formulations. Patients should be advised to seek medical attention promptly if they experience potential symptoms of ddI toxicity such as nausea, vomiting, abdominal pain/distention, fatigue, anorexia, unexplained weight loss, tachypnea, dyspnea, motor weakness, numbness, tingling, and pain in hands and feet.

AccessPak for HIV PEP Expanded with Kaletra

Generic Name: emtricitabine / lopinavir / ritonavir / tenofovir

Brand name: AccessPak for HIV PEP Expanded with Kaletra

Synonyms: n.a.

What is AccessPak for HIV PEP Expanded with Kaletra?

Videx

Generic Name: didanosine

Brand name: Videx, Videx EC

Synonyms: n.a.

What is Videx?