ODIVIR KIT: PLACE IN THERAPY

The lifelong duration of therapy makes adherence a significant challenge. Towards this end, the simplification of antiretroviral regimens represents a key milestone. Odivir Kit is a specially packed kit that contains once-daily doses of three antiretrovirals-efavirenz, didanosine and lamivudine - that are commonly co-prescribed as a triple drug regimen. Furthermore, the specially formulated kit form ensures that patients do not miss even one dose of any drug, since each kit contains one day's quota of drugs.

The current goal of anti-HIV therapy is to achieve a sustained suppression of viral replication using a combination of potent antiretroviral agents. Sustained viral suppression permits immune reconstitution that results in a marked reduction of disease progression and death. Additionally, complete viral suppression delays or prevents the emergence of drug-resistant virus.

In order to achieve this goal, persons living with HIV are often faced with very demanding daily therapeutic schedules. Forgetfulness, frequent dosing, high pill burden, food restrictions, and long-term toxicities have been widely recognized as factors that lead to poor adherence and the consequent emergence of drug-resistant viruses, a frequent pathway for treatment failure. This brings into focus the need for more conveniently dosed, patient-friendly regimens.

Patient surveys clearly indicated the preference for once-daily regimens with low pill burdens. Patients perceive that once-daily regimens would fit best into their lifestyle. Moreover, these surveys also indicate that patients feel that they are less likely to forget taking their dose with a once-daily regimen. This is another important aspect, since forgetfulness is the most commonly cited reason for not taking medications.

In response to this need, once-daily antiretroviral combinations are being evaluated. A promising once-daily regimen is that of efavirenz + didanosine + lamivudine. Both lamivudine and didanosine have long intracellular half-lives, and can be dosed once daily. Lamivudine is already available as a 300 mg tablet. An improved once-daily enteric-coated formulation has also been introduced which has better tolerability and patient appeal. Efavirenz has a favourable pharmacokinetic profile and high antiviral potency. Moreover, recently a 600 mg tablet formulation of efavirenz has been made available, enabling one-pill-a-day dosing, as opposed to the earlier 3 pills-a-day dosing.

Clinical studies using this combination demonstrate its efficacy in reducing viral loads and improving CD4 counts. This regimen was found to be similarly effective in patients with high baseline viral loads. Moreover, the sustained viral suppression achieved with this combination was similar to that obtained in naïve patients with other more complex triple drug regimens (INCAS Study - JAMA 1998; 279: 930-37; Study 006 - NEJM 1999; 341: 1865-73; START II - AIDS 2000; 14: 1601-10

Thus, not only is once-daily administration of efavirenz + lamivudine + didanosine a compact, once daily patient-friendly regimen, it is also associated with sustained virological and immunological benefits.

To conclude, simpler, patient-friendly regimens can improve medication adherence, and help achieve the goals of HAART. The availability of once-daily HAART regimens opens up a whole new chapter in adherence to HAART.