What is true about all antiviral drugs used to treat HIV?

Antiviral drugs used to treat HIV are known to interact with the cytochrome P450 (CYP450) enzyme system in the liver. This interaction is significant because it can affect how these drugs are metabolized in the body. Some HIV medications can either inhibit or induce CYP450 enzymes, leading to altered drug levels in the bloodstream, which can impact efficacy and toxicity. This property not only helps in understanding drug interactions with other medications a patient may be taking but also informs healthcare providers on the appropriate management of those interactions to ensure therapeutic effectiveness and safety in HIV treatment regimens.

The other options, while they may hold some truth in specific contexts, do not universally apply to all HIV antiviral drugs. Some antiviral medications are indeed available in forms other than oral, side effects can vary in severity, and not all are sourced from plants, making the option regarding CYP450 isoenzymes the most accurate and encompassing regarding the characteristics of all drugs in this class.