Disoproxil (tenofovir disoproxil): what it is and when it’s used
Disoproxil usually appears as part of tenofovir disoproxil fumarate (TDF). It’s a prodrug—meaning it converts in your body into the active drug tenofovir. Doctors prescribe TDF mainly for HIV treatment, HIV prevention (PrEP), and chronic hepatitis B. You’ll often see it combined with other antivirals, for example TDF + emtricitabine for PrEP.
How disoproxil works
Once taken by mouth, disoproxil turns into tenofovir diphosphate inside cells. That active form blocks viral reverse transcriptase, an enzyme the virus needs to copy itself. Stopping replication helps control viral load, lower transmission risk, and slow liver damage in hepatitis B.
Safety tips and what to watch for
Common short-term side effects include nausea, diarrhea, headache, and mild stomach upset. The two issues to watch closely are kidney function and bone health. TDF can reduce kidney function in some people and may lower bone mineral density over time.
Before starting TDF, doctors usually check baseline kidney tests (creatinine, eGFR) and may repeat them periodically. If you have reduced kidney function, your dose or choice of drug will change. Long-term users sometimes need a bone density scan if there are risk factors for fracture.
Disoproxil can interact with other drugs. Notable interactions: didanosine (can raise didanosine levels and cause harm) and some boosted HIV protease inhibitors (which can change tenofovir levels). Also avoid strong nephrotoxins together when possible—talk to your provider about NSAIDs, certain antibiotics, and IV contrast.
If you’re pregnant, TDF is commonly used in pregnancy when needed for HIV or hepatitis B, but your provider will weigh benefits and risks and monitor you closely.
Typical adult dosing for TDF is 300 mg once daily for HIV treatment or PrEP, but dosing must be adjusted for reduced kidney function and children. Never change dose or stop without checking with your prescriber.
Storage is simple: keep tablets at room temperature, dry, and away from children. Don’t share prescriptions; formulations and dosing can differ between people.
Thinking about buying TDF online? Only use pharmacies that require a valid prescription, show clear contact info, and have verified credentials. Fake or low-quality medications risk serious harm. If cost is an issue, ask your clinic about assistance programs or generic options.
Questions for your clinician: ask how often your kidneys and bone health will be checked, what other drugs you should avoid, and what symptoms should prompt immediate care (severe fatigue, sudden muscle pain, dark urine, or bone pain). Keep a list of your current medications and supplements to review at each visit.
Need a quick recap? Disoproxil is the prodrug form used in TDF. It’s effective for HIV and hepatitis B but needs kidney and bone monitoring. Use under medical supervision, watch interactions, and get prescriptions only from trusted sources.
