Mutations & Resistance in HIV

Managing Resistance to HIV Therapy
Causes of Treatment Failure
- Rational Treatment Sequencing
- Treatment Choices
- Hidden Dangers?
- Resistance Studies
- Measuring Resistance

Resistance Quiz

References

Credits

Managing Resistance to HIV Therapy

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Rational Treatment Sequencing
Even in individuals who initially respond well to drug treatment, virological control (maintenance of undetectable viral load) may fail eventually (Figure 2). A long term treatment plan is therefore likely to involve a sequence of different anti-HIV drug combinations. If therapeutic benefit is lost it seems logical to switch to other drugs that the individual has not previously tried and to which HIV is unlikely to be resistant.

Figure 2: Durability of response to Triple Therapy
106 Indinivar optimal responders (Virological Load (VL) <500 copies/ml
before week 24 and maintained for >12 weeks)
Holder DJ. HIV Drug Resistance Workshop, St Petersburg 1997: Abstract 129

Choice of initial and subsequent drug therapy should be both uncompromising in terms of drug activity and based rationally on a knowledge of drug resistance and cross-resistance patterns. However, issues such as drug tolerability (severity of side-effects), convenience of administration and low potential for drug interactions will also be critical, because therapy is likely to be life-long¹² (Table 1).

Table 1: Principles guiding drug choice in therapy combinations

Switching anti-HIV treatment as soon as there are signs of drug failure (increased viral load), or when the first mutation is detected, may limit the development of further mutations that may adversely affect the course of the disease or response to subsequent therapies.