Complications of HIV Medications continued...
Some of the best news is that many of the older nucleoside reverse transcriptase inhibitors (NRTIs) that cause severe complications are now either used less or not at all. This includes AZT ( zidovudine), which causes anemia and fat wasting, as well more subtle side effects like headache or nausea. Stavudine and didanosine are no longer prescribed in the U.S because of notable fat wasting, lipid problems, and severe burning and aching in feet and legs ( neuropathy), Taiwo says.
It is now possible to switch patients to better tolerated alternatives, including tenofovir, Taiwo tells WebMD. But there are some "lingering concerns" about its long-term effects on bones and kidneys, so it is a subject of ongoing study.
There are conflicting reports about the potential risks of abacavir, particularly related to cardiovascular problems. Severe allergic reactions are also possible. But for the most part, it’s possible to identify risk through genetic testing, Taiwo says.
HIV Complications With NNRTIs
Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is included in most initial regimens. Central nervous system side effects, including nightmares or trouble sleeping, are a common problem with this drug, Taiwo says. But this complication tends to go away by itself. Patients with seizures or depression may suffer more severe symptoms, however. "More recently, there are reports that efavirenz can affect metabolism of vitamin D," Taiwo says.
The big issue with another NNRTI, nevirapine, is its potential impact on the liver -- particularly in patients with high counts of CD4, immune system cells that HIV attacks. Some patients may also experience severe and potentially life-threatening allergic reactions. However, unlike some other medications, nevirapine has few effects on lipids, which can be an issue if cardiovascular problems are a concern. In fact, nevirapine increases levels of good cholesterol (HDL) in some patients.
HIV Complications With Protease and Integrase Inhibitors
Low-dose ritonavir, a protease inhibitor, is now the norm in all protease-based regimens. The higher the amount of ritonavir, though, the greater the chance of gastric side effects and metabolic complications such as central obesity, insulin resistance, and lipid problems, Taiwo says. Paired with the PIs atazanavir or darunavir, the low-dose ritonavir boosts the drug levels of the primary PIs.
Raltegravir is currently the only FDA-approved integrase inhibitor, but several others are in development. "These novel drugs seem to be very well tolerated," Taifo says.
HIV Complications With Fusion Inhibitors
If you become resistant to other medications, your doctor may prescribe a fusion inhibitor called enfuvirtide. With this medication, it is common to have a reaction at the injection site. This may cause pain and other symptoms. However, complications are not common. A rare hypersensitivity reaction causes symptoms that may include a rash, fever, and nausea, for example. And with this medication, you also have an increased risk of bacterial pneumonia.