Truvada® / Emtricitabine/Tenofovir Disoproxil

Truvada® and its generics (emtricitabine/tenofovir disoproxil) are used for HIV pre-exposure prophylaxis (PrEP). PrEP is a prescription-only medication for HIV-negative people at increased risk of infection; when taken daily, it protects against HIV infection.

Since September 2019, the costs of PrEP in Germany have been covered by the statutory health insurance funds. It is prescribed by specialized physicians or HIV specialist practices. In addition to the brand-name product Truvada®, generics are available that contain identical active ingredients.

Mechanism of action: Emtricitabine is a nucleoside reverse transcriptase inhibitor, tenofovir a nucleotide reverse transcriptase inhibitor:

• Emtricitabine: Is activated in the cell to emtricitabine triphosphate and inhibits HIV reverse transcriptase
• Tenofovir: Is activated to tenofovir diphosphate and likewise blocks reverse transcriptase

Protective mechanism:

• The active ingredients accumulate in the cells that HIV uses as a point of entry
• Upon contact with HIV, viral replication is blocked immediately

Protective effect:

• Protection during anal sex: after 7 days of daily use
• Protection during vaginal sex: after approx. 20 days of daily use

PrEP with Truvada® is suitable for:

• HIV-negative people at increased risk of HIV
• Men who have sex with men (MSM) and have changing partners
• Heterosexual people with an HIV-positive partner (without viral load suppression)
• People who do sex work
• People with changing sexual partners and inconsistent condom use
• People with recurrent STIs

Requirements:

• Confirmed negative HIV test (before starting!)
• Kidney function within the normal range (GFR > 60 ml/min)
• Regular medical check-ups (every 3 months)

Not suitable:

• People with HIV infection (PrEP is NOT an HIV treatment!)
• Impaired kidney function (GFR < 60 ml/min)
• Acute HIV infection or unclear HIV status

Daily PrEP (standard):

• 1 tablet (emtricitabine 200 mg / tenofovir 245 mg) once daily

Lead-in time:

• Anal sex: 7 days of daily use
• Vaginal sex: approx. 20 days of daily use

Event-based PrEP (only for MSM with anal exposure):

• 2 tablets 2–24 hours before sex
• 1 tablet 24 hours after the first dose
• 1 tablet 48 hours after the first dose
• Continue taking for at least 2 days after the last risk exposure

Note: Event-based PrEP has only been studied for MSM (anal exposure). For PrEP, the Summary of Product Characteristics provides only for daily use of one tablet.

Daily intake:

• 1 tablet daily, always at about the same time
• With a meal whenever possible
• Swallow with water

Mandatory tests every 3 months:

• HIV test (before every new prescription!)
• Kidney function (creatinine, GFR)
• STI screening (syphilis, gonorrhea, chlamydia)
• Hepatitis B status (before starting)

Important notes:

• Never start without a prior HIV test!
• If you miss a dose: take it as soon as possible, then continue as usual
• PrEP does NOT protect against other STIs – condoms are still recommended
• When stopping: pay attention to kidney function and hepatitis B status

PrEP must not be taken in cases of:

• HIV infection (even if suspected!) – risk of resistance developing!
• Hypersensitivity to emtricitabine or tenofovir
• Kidney dysfunction (GFR < 60 ml/min)

Caution in cases of:

• Chronic hepatitis B (risk of a hepatitis B flare-up when stopping!)
• Osteoporosis or risk factors for loss of bone mineral density
• Concomitant use of nephrotoxic medications
• Liver diseases

When stopping: With hepatitis B co-infection: Do not stop abruptly! Risk of a severe hepatitis B flare. Medical supervision is mandatory.

Common (1–10%) in the first weeks:

• Nausea (usually temporary, better after 2–4 weeks)
• Headache
• Diarrhea
• Fatigue
• Dizziness

Uncommon (0.1–1%):

• Flatulence
• Skin rash

Long-term side effects (rare):

• Mild impairment of kidney function (reversible after stopping)
• Mild loss of bone mineral (usually not clinically relevant)
• Elevated liver enzymes

Note: Most side effects occur in the first weeks and then subside. PrEP is very safe with regular check-ups. Changes in kidney function are reversible after stopping.

Contraindicated:

• Other medicines containing emtricitabine, tenofovir disoproxil, tenofovir alafenamide or other cytidine analogues such as lamivudine
• Adefovir dipivoxil

Caution with:

• Nephrotoxic medications (NSAIDs with long-term use, aminoglycosides)
• Ledipasvir/sofosbuvir (tenofovir levels may rise)
• Didanosine: concomitant use not recommended (increased toxicity)

No problem:

• Hormonal contraception (pill, hormonal IUD, etc.)
• Most common medications
• Alcohol (in moderation)