Changing treatment

If you can’t tolerate one treatment, then you can switch to an alternative. It is vitally important that you discuss the issues involved with your doctor.

Reasons to change treatment
Switching between nukes
Switching between NNRTIs
Switching between PIs
Using new drugs and new classes of drugs

Reasons to change treatment

As many side effects become easier over the first few weeks of treatment, if your initial symptoms are only mild or moderate, seeing whether they settle down before changing treatment, can be good advice.

But, if you can’t tolerate one treatment, then you can switch to an alternative without it affecting your future options.

If you are considering stopping or interrupting any treatment it is vital that you discuss this with your doctor.

The decision to change treatment in order to manage side effects will depend on whether:

there are other HIV drugs you can use.
the side effects are likely to get worse if you remain on the same drugs.
you think that the side effects are related to drugs. Even though there may not have been a proven link, this may be a new report, and you may be the first person to experience this.

Close monitoring after a change of drugs will help you know whether the treatment that you switched from was causing that side effect.

Switching individual drugs is safe and can improve your quality of life - and still keep your viral load undetectable.

When switching drugs it may be safer to add in the new drug to check that it is tolerable before discontinuing the drug that is causing the side effect. If you have a detectable viral load before switching you should also have a resistance test first.

If your current combination is not your first treatment, your treatment history will determine your options,

Changing only one or two drugs in a combination is only recommended when viral load is undetectable prior to the switch. Some people may switch to four or more drugs if they have resistance from earlier combinations.

Switching between nukes

Most combinations involve at least two ‘nukes’ (AZT, d4T, ddI, 3TC, FTC, abacavir, tenofovir).

So long as you haven’t developed resistance to the other nucleosides (and you don’t use AZT and d4T together; or 3TC and FTC together in the same combination), you can use these drugs in many different combinations.

If you get peripheral neuropathy (pain or numbness in your hands or feet) this may be due to d4T, ddI or 3TC and you should switch or reduce the doses of those drugs, before the neuropathy becomes more serious.
d4T and AZT are associated with fat loss from the face, arm and legs. Switching to abacavir or tenofovir will reduce this risk and may reverse previous fat loss.
If you continue to get nausea or fatigue using AZT (or Combivir or Trizivir, which both contain AZT) then you could switch to another nuke.

Switching between NNRTIs

Nevirapine and efavirenz have similar potency but they have different side effect profiles. Nevirapine has been more associated with skin rash and liver toxicity – usually in the first 1-2 months of treatment. Efavirenz is linked to mood disturbance, disturbed sleep patterns and vivid dreams when starting and more rarely in the long term.

If you have difficult side effects from one of these drugs, you should be able to switch from one to the other without stopping treatment or changing your other drugs.

Switching between PIs

Switching from one PI to another is also straight-forward, especially if both PIs are being boosted by ritonavir.

Switching ffom one boosted PI to another (such as from Kaletra to atazanavir/r) is likely to be okay
Switching between PIs used in dual-PI combinations, although less well studied, is also likely to be okay
Switching from a boosted PI to an unboosted PI is not recommended unless drug levels are checked with TDM

Using new drugs and new classes of drugs

One of the advantages of new drugs is that they hopefully have fewer side effects.

In 2008 there are several new drugs available including drugs that work in different ways.

These include the integrase inhibitor raltegravir, the CCR5 inhibitor maraviroc, a new NNRTI called etravirine and a new protease inhibitor called darunavir.

Each of these drugs may have a different role as switch options based on their side effects.

For example, raltegravir does not increase cholesterol or triglycerides. As a drug from a new class, it could also be used as a switch option for people who are currently having trouble with T-20.

Darunavir uses a lower boosting dose of ritonavir than some other protease inhibitors, and may be more tolerable than drugs that need a higher ritonavir dose.

As each new drug becomes more widely used, they will probably be used as switch options.

Each choice will be individually based on your situation and treatment history.

It may also depend on how the drug is licensed and on practical issues like cost.