Fixed-dose combinations

Some pharmaceutical companies have produced fixed-dose combinations that contain two or more drugs in a single tablet. The currently licensed brand-name coformulations are:

  • Combivir: AZT + 3TC.
  • Kivexa: 3TC + abacavir.
  • Trizivir: AZT + 3TC + abacavir.
  • Truvada: tenofovir + emtricitabine.
  • Atripla: tenofovir + emtricitabine + efavirenz.
  • Kaletra: lopinavir + boosting dose of ritonavir.

Other fixed-dose coformulations containing these and other drugs are produced by generic drug manufacturers for use in resource-limited countries.

Fixed-dose combinations allow patients to take fewer pills. Atripla, for example, packs a complete two-class antiretroviral regimen into a single once-daily pill. In order to gain regulatory approval, companies must show that a fixed-dose tablet works as well as the separate drugs used together.

The drawback of fixed-dose combination pills is that the dosages of the individual drugs cannot be adjusted independently. This might be a problem, for example, if a person with kidney disease needs to take a lower than usual dose of tenofovir. For such people, using the separate pills may be a better option.