In a patient with reduced bone mineral density, is HIV pre‑exposure prophylaxis (PrEP) safe, and which PrEP regimen is recommended?

Yes, PrEP is Safe for Patients with Bone Density Issues—Use TAF/FTC Instead of TDF/FTC

For patients with reduced bone mineral density (osteopenia or osteoporosis), daily oral TAF/FTC (tenofovir alafenamide/emtricitabine) is specifically recommended over TDF/FTC (tenofovir disoproxil fumarate/emtricitabine) for HIV pre-exposure prophylaxis 1.

Recommended Regimen for Bone Density Issues

• TAF/FTC daily oral dosing is the preferred PrEP regimen for individuals with known osteopenia or osteoporosis 1
• This recommendation applies regardless of gender or exposure type (with the exception that TAF/FTC should be limited to those whose exposures do not include receptive vaginal/neovaginal sex or injection drug use alone) 1

Why TAF/FTC Over TDF/FTC?

The guideline explicitly addresses this concern because TDF-containing regimens cause measurable bone mineral density loss:

• TDF/FTC causes a 1-3% BMD decline at the hip, femoral neck, and lumbar spine over 12-48 months 2, 3, 4
• At 48 weeks, TDF arms showed -1.05% median BMD change at the hip versus 0.0% in non-TDF arms (p=0.001) 2
• These losses are small, non-progressive, and reversible upon discontinuation 5, 6
• However, for someone already starting with compromised bone density, avoiding additional BMD loss is prudent

TAF/FTC was developed specifically to address this issue and has a more favorable bone safety profile than TDF/FTC.

Important Caveats About TAF/FTC

TAF/FTC cannot be used for:

• Receptive vaginal or neovaginal exposures (insufficient tissue drug concentrations)
• Prevention through injection drug use alone
• These patients must use TDF/FTC despite bone concerns 1

Alternative: Long-Acting Injectable Cabotegravir

Long-acting cabotegravir (every 6 months) is another excellent option for patients with bone density concerns 1:

• No bone mineral density effects (non-tenofovir based)
• Highly effective (96-100% efficacy in trials) 7
• Appropriate for all exposure types including vaginal and injection drug use
• Does not require consideration of bone health in prescribing decisions

Screening Is Not Required

Bone density scans (DXA) are not necessary before initiating tenofovir-based PrEP 1. This is an evidence rating AIII recommendation, meaning:

• You can prescribe PrEP based on known history of osteopenia/osteoporosis
• Obtaining a DXA scan should not delay PrEP initiation
• If the patient already has documented bone density issues, simply choose TAF/FTC or cabotegravir

Clinical Algorithm

For patients with known reduced BMD who need PrEP:

1. First choice: TAF/FTC daily oral IF exposures are limited to receptive anal sex or insertive sex only
2. First choice: Long-acting cabotegravir (every 6 months) for any exposure type, including vaginal or injection drug use
3. If neither option above is feasible: TDF/FTC can still be used—the bone effects are reversible and the HIV prevention benefit outweighs the small BMD decline risk 5, 6

For patients without known BMD status:

• Do not delay PrEP for DXA screening 1
• Initiate appropriate regimen based on exposure type and other factors
• Consider TAF/FTC if patient has risk factors for low BMD (underweight, older age, steroid use, etc.)

Risk-Benefit Context

The absolute fracture risk from PrEP-related BMD loss is extremely low and must be weighed against the substantial benefit of HIV prevention 5, 6. Even in patients with baseline bone concerns, preventing HIV acquisition—which itself causes bone loss and increases fracture risk—is the priority outcome for mortality and quality of life.