Abacavir Sulfate and Zonisamide

• Generic Name: abacavir
• Dosage Forms: n.a.
• Other Brand Names: Ziagen

Treatment of HIV-1 infection in adults, adolescents, and pediatric patients ≥3 months of age; used in conjunction with other antiretrovirals.

Single-entity abacavir used with another NRTI (dual NRTIs) in conjunction with an HIV integrase strand transfer inhibitor (INSTI), HIV nonnucleoside reverse transcriptase inhibitor (NNRTI), or HIV protease inhibitor (PI) in INSTI-, NNRTI-, or PI-based regimens. Also commercially available in fixed combinations containing abacavir and lamivudine with or without a third antiretroviral; these fixed combinations used in certain patient groups to decrease pill burden and improve compliance.

For initial treatment in HIV-infected adults and adolescents, experts state that the dual NRTI option of abacavir and lamivudine is a recommended dual NRTI option for use in most INSTI-, NNRTI-, and PI-based regimens, but should be used only in patients who are HLA-B*5701 negative.

For initial treatment in antiretroviral-naive pediatric patients, experts state that abacavir and lamivudine (or emtricitabine) is a preferred dual NRTI option and abacavir and zidovudine is an alternative dual NRTI option for use in PI-, NNRTI-, or INSTI-based regimens in children ≥3 months of age who are HLA-B*5701 negative.

Abacavir/lamivudine fixed combination (Epzicom) can be used in adults and pediatric patients weighing ≥25 kg when dual NRTI option of abacavir and lamivudine is indicated; used in conjunction with antiretrovirals from another class (not another NRTI).

Abacavir/dolutegravir/lamivudine fixed combination (Triumeq) can be used in adults; used alone as a complete treatment regimen or in conjunction with other antiretrovirals.

Abacavir/lamivudine/zidovudine fixed combination (Trizivir) can be used in adults and adolescents weighing ≥ 40 kg; used alone as a complete treatment regimen or in conjunction with other antiretrovirals. Intended only for regimens that require all 3 drugs; data limited regarding use in patients with baseline viral loads >100,000 copies/mL.

Triple NRTI regimen of abacavir, lamivudine, and zidovudine not recommended for initial treatment in antiretroviral-naive patients because of inferior antiretroviral activity.

Triple NRTI regimen of abacavir, tenofovir disoproxil fumarate (tenofovir DF), and either lamivudine or emtricitabine not recommended at any time because of high rate of virologic failure.

Do not use abacavir or fixed combinations containing abacavir in HLA-B*5701-positive individuals. (See Hypersensitivity Reactions under Cautions.)

Postexposure prophylaxis of HIV infection following occupational exposure (PEP) in health-care personnel and others exposed via percutaneous injury (e.g., needlestick, cut with sharp object) or mucous membrane or nonintact skin (e.g., chapped, abraded, dermatitis) contact with blood, tissue, or other body fluids that might contain HIV.

USPHS recommends 3-drug regimen of raltegravir in conjunction with emtricitabine and tenofovir DF as the preferred regimen for PEP following occupational exposures to HIV. Abacavir is one of several alternative agents that may be used in PEP regimens, but use only with expert consultation since HLA-B*5701 testing required and such testing may not be available or practical prior to initiating PEP.

Management of occupational exposures to HIV is complex and evolving; consult infectious disease specialist, clinician with expertise in administration of antiretroviral agents, and/or National Clinicians’ Postexposure Prophylaxis Hotline (PEPline at 888-448-4911) whenever possible. Do not delay initiation of PEP while waiting for expert consultation.

Antiretrovirals are used for postexposure prophylaxis of HIV infection following nonoccupational exposure (nPEP) in individuals exposed to blood, genital secretions, or other potentially infectious body fluids that might contain HIV when the exposure represents a substantial risk for HIV transmission.

When nPEP indicated in adults and adolescents ≥13 years of age with normal renal function, CDC states preferred regimen is either raltegravir or dolutegravir used in conjunction with emtricitabine and tenofovir DF (given as emtricitabine/tenofovir DF; Truvada); recommended alternative in these patients is ritonavir-boosted darunavir used in conjunction with emtricitabine/tenofovir DF.

CDC states do not use abacavir in any nPEP regimens; need for prompt initiation of nPEP does not allow time for HLA-B*5701 screening.

Consult infectious disease specialist, clinician with expertise in administration of antiretroviral agents, and/or the National Clinicians’ Postexposure Prophylaxis Hotline (PEPline at 888-448-4911) if nPEP indicated in certain exposed individuals (e.g., pregnant women, children, those with medical conditions such as renal impairment) or if considering a regimen not included in CDC guidelines, source virus is known or likely to be resistant to antiretrovirals, or healthcare provider is inexperienced in prescribing antiretrovirals. Do not delay initiation of nPEP while waiting for expert consultation.

• Generic Name: zonisamide
• Dosage Forms: n.a.
• Other Brand Names: Zonegran

Zonisamide is a sulfa drug with anti-convulsant effects.

Zonisamide is used together with other anti-convulsant medications to treat partial seizures in adults with epilepsy.

Zonisamide may also be used for purposes not listed in this medication guide.