Table 1. Drug therapy used to treat HBV.
Costing is based on the International Medical Products Price Guide: http://mshpriceguide.org/en (data accessed May 2017. Price for lamivudine (3TC)—South Africa Department of Health; Price for tenofovir (TDF)—Supply Chain Management Project; price for HBV immunoglobulin (HBIG)—Sudan Medicins Sans Frontieres). WHO essential medicines: http://who.int/medicines/publications/essentialmedicines/EML_2015_FINAL_amended_NOV2015.pdf?ua=1.
| Drug name | Drug class | Potency against HBV* | Resistance | Severe adverse effects | Safe in pregnancy? | Use in children | Use as part of combined ART? | WHO “essential medicine” | Monitoring | Cost (International Medical Products Price Guide) |
|---|---|---|---|---|---|---|---|---|---|---|
| Tenofovir (TDF) | Nucleotide reverse transcriptase inhibitor | + | Rare | Lactic acidosis, hepatitis, renal injury, bone demineralization | Yes | >12 years for HBV** | Yes | Yes | LFTs, renal function | US$3.91/month |
| Entecavir (ETV) | Nucleoside reverse transcriptase inhibitor | ++ | <10% at 3 years. Increased in 3TC resistance | Lactic acidosis, steatosis | Not known | From age 2 years | No | Yes | LFTs, FBC | Not listed |
| Lamivudine (3TC) | Nucleoside reverse transcriptase inhibitor | + (potentially limited by resistance) | 50% at 3 years. Best-recognized mutations are in YMDD motif in viral polymerase. | Lactic acidosis, hepatomegaly and steatosis, pancreatitis | Yes | From birth | Yes | Yes | LFTs, FBC | US$1.43/month |
| Interferon (IFN) | Biologic response modifier | + (genotype dependent) | No | Anorexia, diarrhea, flu-like symptoms, neurotoxicity, seizures, hepatotoxicity | No | Not recommended in children (>18 years only)*** | N/A | Yes | LFTs, FBC, TFTs | Not listed |
| HBV immuno-globulin (HBIG) for prophylaxis | Biologic response modifier | ++ | N/A | Abdominal pain, buccal ulceration, chest pain | Yes | From birth | N/A | No | N/A | US$38.02/dose |
Abbreviations: ART, antiretroviral therapy (for HIV infection); FBC, full blood count; HBV, hepatitis B virus; LFT, liver function test; N/A, nonapplicable; TFT, thyroid function test; YMDD, tyrosine-methionine-aspartic acid-aspartic acid motif.
*Potency against HBV is defined as + or ++ to differentiate between agents with lower and higher suppressive capacity, respectively.
** British National Formulary (https://www.bnf.org/) states tenofovir can be prescribed for HIV in infants >2 years, but data for HBV treatment are lacking.
*** British National Formulary (https://www.bnf.org/) states Peg-interferon-alpha can be prescribed for chronic hepatitis C virus (HCV) in infants >5 years, but data for HBV treatment are lacking. https://www.medicinescomplete.com/mc/bnfc/current/