There are currently three non-nucleoside agents approved for use in HIV treatment. However, patients can develop resistance to this class of drugs, so it is vital that they take them in accordance with the direction of their healthcare providers. Cross-resistance in this class (resistance to one drug causing resistance to the others) is also very common. If cross resistance develops, then patients will be resistant to all the drugs in the class and so the class cannot be used.

Of the four classes of HIV medications, this class of drugs seems to be best tolerated by most people. Even the most bothersome side effects are time limited and can be managed by the primary care provider and the patient.

Not all people react to medications in the same way. Some can have fewer and others can have more or different side effects. It is very important that providers and patients discuss potential side effects and their treatment in detail before any antiretroviral regime is started.

Efavirenz

Efavirenz is taken once-a-day. The most common side effects reported by patients taking Efavirenz are central nervous system side effects. Sleep disturbances may occur. For most patients, this side effect lasts only 6 to 8 weeks and is manageable. Efavirenz is typically taken at bedtime because it can cause sleepiness. However, each patient needs to find his or her own best time of day to take this medication since it can affect everyone differently. If a patient wakes up feeling sluggish, for example, they should take their medication earlier in the evening to minimize any morning lethargy.

It is believed that taking this medication on an empty stomach will minimize vivid dreaming, which can cause sleep disturbances. Depression and other psychiatric problems and symptoms can be aggravated by Efavirenz, so it is important to perform a careful evaluation and screening for these problems prior to starting therapy.

Rash with Efavirenz is rarely life threatening, and most patients can be treated with over-the-counter medications until the rash resolves, while remaining on Efavirenz. There have been a very small number of reports of Stevens Johnson Syndrome (SJS), which is a life-threatening condition. SJS is characterized by painful blistering of the skin and mucus membranes, which is typically preceded by flu-like symptoms. 

If a patient has any rash, it should be reported to the primary care provider as soon as possible for evaluation. Any rash that also includes mouth ulcers, fevers, or nausea and vomiting needs to be reported immediately.

Efavirenz can cause birth defects, so women should not get pregnant or breast-feed infants while taking this drug. Therefore, it is recommended that women be counseled on using two forms of birth control while on the drug.1

Nevirapine

Women who take Nevirapine may be at increased risk of pregnancy because a recently released study suggests that Nevirapine may reduce the effectiveness of oral contraceptives. Patients should be counseled on using barrier birth control while on Neviapine.2

Rash can be common with Nevirapine, and that is one reason this drug is started on a once-daily regimen for the first 2 weeks as a lead-in dose before the dose is increased to twice-daily. If patients get a rash with Nevirapine, it is very important that it be reported to the primary care provider as soon as possible The risk of getting a rash is greatest in the first 42 days of therapy.

Liver toxicity has been reported with Nevirapine, so it is very important that any nausea, vomiting, abdominal pain, fever, skin yellowing (jaundice), or flu-like symptoms or fatigue be reported immediately to the primary care provider. Although developing liver toxicity with Nevirapine is rare, it can be life-threatening. It is important that liver function testing be done while patients are on this drug.

Delavirdine

Rash can also be a common side effect while taking Delavirdine; it occurs in about 1 out of 5 patients. The rash usually appears about 1 to 3 weeks after starting the drug;  in most cases it can be treated with over-the-counter medications. There are many drug-drug interactions with Delavirdine, so it is very important to identify all medications and assess for any potential interactions.

Jon Gothing, RN, BSN is a registered professional nurse at the Massachusetts General Hospital Infectious Disease outpatient unit.

Sheila Davis, MSN, ANP, ACRN is an Adult Nurse Practitioner at the Massachusetts General Hospital Infectious Disease Unit.

References:

     1.   US Food and Drug Administration Report. Available online at: <http://www.fda.gov/fdac/ departs/1999/199_upd.html>

     2.   Mildvan D, Yarrish R, Marshak A, et al. Pharmacokinetic interaction between nevirapine and ethinyl estradiol/norethindrone when administered concurrently to HIV-infected women.

J Acquired Immune Deficiency Syndromes. 2002;29:.

Other Resources

Johns Hopkins AIDS Website: <http://www.hopkins-aids.edu> <http://www.thebody.com>