Classification: NRTI

Mechanism of Action:

Chemically similar to nucleotides

Bind to catalytic site of reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

Serious, possibly fatal hypersensitivity reaction

All NRTIs: Lactic acidosis and severe hepatic steatosis may occur

Contraindications: Positive HLA-B*5701 allele

Side Effects: N/V, Headache, Rash, Increased LFTs, Hypersensitivity

Monitoring: LFTs, signs and symptoms of hypersensitivity

Drug Interactions: Ribavirin: may increase NRTI levels

Role in therapy (preferred, acceptable, or avoid): Acceptable

Available combinations:

+Lamivudine

+Lamivudine and Zidovudine

Classification: NRTI

Mechanism of Action: 

Chemically similar to nucleotides

Binds to catalytic site of reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

Pancreatitis (sometimes fatal)

Lactic acidosis and severe hepatic steatosis

Contraindications: Concurrent use of allopurinol or ribavirin

Side Effects:

Peripheral neuropathy

Nausea/vomiting/diarrhea

Retinal changes and optic neuritis (rare)

Insulin resistance

Portal hypertension

Possible increased risk of MI

Monitoring: LFT, eye exam, CBC, blood chemistry, renal function (must decrease dose if CrCl <60), amlyase and lipase (with pancreatitis)

Drug Interactions:

Avoid combination with stavudine (inc. risk of pancreatitis, peripheral neuropathy, and hyperlactatemia)

Avoid combination with tenofovir (inc. resistance and virologic failure)

Role in therapy (preferred, acceptable, or avoid): avoid

Available combinations: None

Classification: NRTI

Mechanism of Action:

Chemically similar to nucleotides

Binds to catalytic site of reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

May exacerbate Hepatits B once drug is discontinued or HBV resistance may develop

Lactic acidosis and hepatic steatosis

Contraindications: --

Side Effects: Hyperpigmentation of palms/soles, N/V/D

Monitoring: LFTs, renal function

Drug Interactions:

Avoid with lamivudine (no clinical benefit)

Ribavirin may inc. levels of NRTIs (inc. risk of lactic acidosis)

Role in therapy (preferred, acceptable, or avoid): Preferred

Available combinations:

+Tenofovir (Truvada)

+Efavirenz and tenofovir (Atripla)

+Tenofovir, Elvitegravir, and Cobicistat (Stribild)

Classification: NRTI

Mechanism of Action:

Chemically similar to nucleotides

Binds to catalytic site of reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

Do not use the HBV version for treatment of HIV (contains lower doses)

May exacerbate Hepatitis B once drug is discontinued or Hepatitis B resistance may develop

Lactic acidosis and hepatic steatosis

Contraindications: --

Side Effects: Headache, N/V/D

Monitoring: LFTs, renal function

Drug Interactions:

Avoid combining with emtricitabine (No benefit)

Role in therapy (preferred, acceptable, or avoid): Preferred

Available combinations:

+Zidovudine (Combivir)

+Abacavir (Epzicom)

+Abacavir and zidovudine (Trizivir)

Classification: NRTI

Mechanism of Action:

Chemically similar to nucleotides

Binds to catalytic site on reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

Pancreatitis (sometimes fatal) has occurred during combination with didanosine

Lactic acidosis and hepatic steatosis

Contraindications: --

Side Effects: Insulin resistance, peripheral neuropathy, lipoatrophy, hyperlipidemia

Monitoring: LFTs, renal function (must decrease dose when CrCl <50), signs and symptoms of peripheral neuropathy, lipids

Drug Interactions:

Avoid combination with didanosine (inc. risk pancreatitis, peripheral neuropathy, and hyperlactatemia)

Do not combine with zidovudine (Antagonistic)

Role in therapy (preferred, acceptable, or avoid): Avoid

Available combinations: --

Classification: NRTI

Mechanism of Action:

Chemically similar to nucleotides

Binds to catalytic site of reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

Associated with bone marrow suppression/hematologic toxicities (neutropenia and anemia), especially in advanced HIV

Prolonged use associated with symptomatic myopathy

Lactic acidosis and hepatic steatosis

Contraindications: --

Side Effects: N/V, nail hyperpigmentation, myopathy, lipoatrophy, insulin resistance, hyperlipidemia, bone marrow suppression, macrocytic anemia

Monitoring: CBC, LFTs, mean corpuscular volume (MCV), CPK, lipids

Drug Interactions: 

Avoid combining with stavuidne (antagonistic)

Role in therapy (preferred, acceptable, or avoid): Acceptable

Available combinations:

+Lamivudine (Combivir)

+Abacavir and lamivudine (Trizivir)

Classification: NRTI

Mechanism of Action:

Chemically similar to nucleotides

Binds to catalytic site of reverse transcriptase, preventing viral RNA from being transcribed into DNA

Black Box Warnings:

May exacerbate Hepatitis B once drug is discontinued or HBV resistance may develop

Lactic acidosis and hepatic steatosis

Contraindications: --

Side Effects:

Fanconi syndrome (excreting lots of stuff that you shouldn't in urine), renal insufficiency, osteomalacia and decreased bone density

GI upset (N/V/D)

Monitoring: LFTs, CBC, renal function, phosphorus, UA, bone density (long term)

Drug Interactions:

Avoid use with didanosine due to resistance and virologic failure, as well as inc. didanosine conc.

Role in therapy (preferred, acceptable, or avoid): Preferred

Available combinations:

+Emtricitabine (Truvada)

+Emtricitabine and Efavirenz (Atripla)

+Emtricitabine, Elvitegravir, and Cobicistat (Stribild)