HIV pre-exposure prophylaxis (PrEP) in Singapore.

HIV PrEP (pre-exposure prophylaxis) is a prescription medication taken by HIV-negative individuals to prevent HIV infection. It is an established preventive intervention when taken as prescribed.⁵

什么是PrEP。 PrEP is typically a daily or on-demand tablet containing TDF/FTC or TAF/FTC. In Singapore, these are dispensed as originator tablets, not generics. The same medications are also part of HIV treatment regimens; used preventively in HIV-negative individuals, they prevent the virus from establishing infection if exposure occurs.

PrEP的有效性如何。 When taken as prescribed (daily or correctly on-demand), PrEP substantially reduces sexual HIV transmission. Effectiveness drops with missed doses - adherence is the single biggest factor in real-world outcomes. PrEP also reduces transmission via injection drug use, though by a somewhat smaller margin.

谁适合使用PrEP。 PrEP is appropriate for any HIV-negative person with ongoing potential exposure to HIV through sexual contact. The clinical guidelines are not restrictive - anyone who wants additional protection and meets basic safety criteria can consider PrEP. Common situations include: partner of a person living with HIV (particularly during conception planning or if their viral load is not yet undetectable); sexual contact with multiple partners or higher-frequency activity; inconsistent condom use; history of multiple STIs; recent PEP use suggesting ongoing exposure risk.

谁不适合使用PrEP。 People already living with HIV (full HIV treatment regimens are needed instead); anyone with significantly reduced kidney function; anyone with chronic hepatitis B taking certain other treatments; anyone with allergy to the components. A baseline workup determines eligibility individually. Most people are eligible.

Singapore context. PrEP is available in Singapore through private clinics like Hisential. It is not currently subsidised under the public healthcare system - it is a private, paid preventive intervention requiring prescription after a baseline HIV-negative test. Quarterly clinical and laboratory monitoring is required for ongoing prescription.

当PrEP作为综合性健康策略的一部分使用时效果最佳——配合使用避孕套（可预防其他性传播感染）、常规 性病检测、疫苗接种以及明智的性决策。它不能替代避孕套，但却是一种强有力的补充。

药物。 The daily PrEP regimen is a combination tablet containing TDF/FTC or TAF/FTC. Both work by blocking reverse transcriptase, an enzyme HIV uses to integrate into host cells. When the drugs are present in tissue at adequate concentration, HIV cannot establish infection even if exposure occurs.

两种给药方案。

每日服用PrEP - one tablet of TDF/FTC or TAF/FTC every day at approximately the same time. The most studied regimen with the most flexible application - protection extends across all sexual contact, including unplanned situations. After 7 days of daily dosing, full protection is established for rectal exposure; 21 days for vaginal exposure.⁵

按需（2-1-1）PrEP - event-driven dosing for individuals whose situations are predictable enough to plan around: 2 tablets of TDF/FTC taken 2-24 hours before sex (ideally 2-12 hours), 1 tablet 24 hours after the first 2-pill dose, and 1 tablet 48 hours after the first 2-pill dose. If multiple sexual encounters occur over several days, continue with 1 tablet daily during the active period, then continue 2 days after the last encounter. On-demand dosing is well-studied for men who have sex with men (MSM); it is less established for women due to slower drug accumulation in vaginal tissue. On-demand dosing has not been studied with TAF/FTC.⁴

依从性与有效性。 Daily PrEP with near-perfect adherence is the most protective option.⁵ Daily PrEP with occasional missed doses (4+ tablets per week) is somewhat less protective. With frequent missed doses (under 2 tablets per week), effectiveness drops substantially. On-demand 2-1-1 taken correctly is comparable to daily PrEP for MSM.⁴ 依从性是唯一最重要的因素。

副作用。 通常耐受性良好。首月最常见症状：轻微肠胃不适、头痛、疲劳——通常会自行缓解。罕见但较严重的情况：肾功能变化（每季度监测肌酐和eGFR）、骨密度轻微变化（通常临床意义不大）、乙肝携带者停药后可能出现乙肝复发（通过协调护理管理）。对于大多数使用者，PrEP可长期服用，且无显著持续影响。

PrEP无法预防的疾病。 PrEP可预防HIV，但不能预防其他性传播感染（STI），如衣原体、淋病、梅毒、肝炎、HPV和疱疹。因此，结构化的 性病检测 至少每3个月一次的检查是PrEP护理的一部分。避孕套对于预防HIV和STI的综合防护依然有效。

综合护理整合。 Hisential的PrEP服务整合了 性病检测, 艾滋病毒检测、疫苗接种（乙肝、HPV）以及 性病治疗 （如果检测到任何并发感染）。 艾滋病毒 (HIV) 暴露后预防 (PEP) 适用于未服用PrEP或PrEP依从性显著不足时发生的任何特定高风险暴露。

就诊前。 您的个人健康礼宾员会分享一份简短的摄入表，涵盖一般健康状况、当前药物以及任何具体问题或疑虑。请携带身份证件以进行实验室检测。

就诊期间。 The initial PrEP consultation lasts 45-60 minutes - longer than routine visits because we are planning a long-term intervention. Our medical team takes a focused history covering reasons for considering PrEP, sexual activity context, current prevention strategies, prior STI history, current medications, kidney health, hepatitis B status if known, and any specific questions.

对话客观且基于尊重——您考虑 PrEP 的原因无需辩解。临床任务是根据您的情况匹配合适的方案，并确保基线检查是安全的。

检查简短且通常有限。样本采集：抽血进行 HIV、肾功能、乙型肝炎和丙型肝炎、梅毒及其他相关检测。尿液样本用于检测衣原体和淋病。必要时进行咽拭子和/或直肠拭子采样。如果您希望在咨询期间获得快速 HIV 检测结果，我们也可以提供——这对于那些希望在开始前立即确认 HIV 阴性状态的人很有用。

通常不会在首次就诊时开具处方——我们会等待完整的基线结果（通常为 3-5 个工作日）后再开始 PrEP。这能确保安全性。在某些情况下，立即进行经验性用药是合适的；我们会针对个人情况进行讨论。

就诊后。 您的个人健康礼宾员会联系您告知基线结果。如果一切正常且适合使用 PrEP，我们将开具处方。首次续药通常为 1 个月，以便我们确认耐受性；后续续药为每 3 个月一次，与季度复诊保持一致。随后进行季度复诊——每次 15-20 分钟，包括抽血和简短评估。

保密性。 Records are encrypted. Hisential does not share information with employers, family members, or insurers without your explicit consent, except where required by regulations or law. PrEP prescriptions are not added to any external medical record without your specific approval, except where required by regulations or law.