Table of ContentsView AllTable of ContentsUsesBefore TakingDosageSide EffectsWarnings & Interactions
Table of ContentsView All
View All
Table of Contents
Uses
Before Taking
Dosage
Side Effects
Warnings & Interactions
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PrEP is not intended for everyone but is rather used in people who are at high risk of HIV infection. This includesserodiscordant couplesin which one partner isHIV-positiveand the other isHIV-negative.
Taking PrEP does not mean you can stopusing condomsor avoid traditional risk-reduction strategies. The drugs used for PrEP do not prevent other sexually transmitted or blood-borne infections, including hepatitis C.
Truvada was the first drug approved for PrEP in 2012.Descovy (which includes an “improved” version of tenofovir that may be less impactful on the kidneys) was approved in October 2019 forcisgendermen andtransgenderwomen.The first injectable form of PrEP, Apretude, was approved in December 2021.
The Need for Condoms on PrEP, the HIV Prevention Pill
PrEP is used in people who are more likely to be diagnosed with HIV as well as anyone in whom the preventive therapy may be considered beneficial.
PrEP LimitationsTruvada is approved for use in PrEP in both cisgender men and women as well as transgender men and women. By contrast, Descovy is only approved for cisgender men and transgender women due to the lack of cisgender women and transgender men in clinical trials. Studies are currently underway to evaluate Descovy for PrEP in people who engage in receptive vaginal sex.
PrEP Limitations
Truvada is approved for use in PrEP in both cisgender men and women as well as transgender men and women. By contrast, Descovy is only approved for cisgender men and transgender women due to the lack of cisgender women and transgender men in clinical trials. Studies are currently underway to evaluate Descovy for PrEP in people who engage in receptive vaginal sex.
According to guidance from the U.S. Preventive Services Task Force (USPSTF), PrEP is recommended for the following groups:
In addition, adolescents or adults considering PrEP must weigh at least 77 pounds (35 kilograms) to be candidates for treatment.
Because the dosing for PrEP is fixed and cannot be modified, people weighing less than 77 pounds would need to use othertraditional preventive strategies.
Although people at low risk of infection can benefit from PrEP, there are risks associated with treatment (see “Side Effects” below) as well as potential costs. For these individuals, condoms and other traditional preventive strategies may be a more practical solution.
What Is the Risk of HIV From Oral Sex?
Prior to starting PrEP, your healthcare provider will need to confirm that you do not have HIV. This requires a simple blood test, either in the form of arapid HIV test(which can return results in around 20 minutes) or a standardpoint-of-care test(which usually returns results in a couple of days).
Truvada and Descovy should not be used in anyone with acreatinine clearanceof less than 30 milliliters per minute (mL/min). Values under 30 mL/min are an indication of severe kidney impairment.
You may also be screened for sexually transmitted infections, includinghepatitis B. Apregnancy testis also recommended if you are in your child-bearing years.
Precautions and Considerations
PrEP should be delayed in anyone who hassigns of a recent HIV infection. This is because HIV tests are designed to detectantibodies, which can take up to a month to develop after exposure to the virus. During this so-called"window period,“an HIV test can return afalse-negative result, meaning that you have HIV even if the test says otherwise.
Symptoms of acute HIV infection (also known asacute retroviral syndrome) are often flu-like and include:
You should also delay PrEP if you’ve had a possible exposure to HIV within the past month, either through unprotected sex, sex with a partner of unknown status, or shared needles.
How Is HIV Transmitted?
When used for PrEP, the recommended dose of Truvada and Descovy is one tablet daily taken with or without meals. The tablet must be taken every day to achieve optimal protection.
Apretude is administered first as two initiation injections given one month apart, and then every other month thereafter. Each injection is 600 mg.
Additionally, long-acting injectable PrEP (Apretrude) has been shown to be more effective in reducing the risk of sexually-acquired HIV than daily oral PrEP.
Modifications
How to Take PrEP On-DemandThe International Antiviral Society USA recommends PrEP on-demand on a “2-1-1” schedule, namely:Two tablets of Truvada are taken two to 24 hours before sex.One tablet is taken 24 hours after the first dose.A final tablet is taken 24 hours later.If the partners engage in sex before the end of the 48-hour period, they should continue to take PrEP every 24 hours until 48 hours after their last sexual episode.
How to Take PrEP On-Demand
The International Antiviral Society USA recommends PrEP on-demand on a “2-1-1” schedule, namely:Two tablets of Truvada are taken two to 24 hours before sex.One tablet is taken 24 hours after the first dose.A final tablet is taken 24 hours later.If the partners engage in sex before the end of the 48-hour period, they should continue to take PrEP every 24 hours until 48 hours after their last sexual episode.
The International Antiviral Society USA recommends PrEP on-demand on a “2-1-1” schedule, namely:
If the partners engage in sex before the end of the 48-hour period, they should continue to take PrEP every 24 hours until 48 hours after their last sexual episode.
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If you decide to pursue oral PrEP as a preventive strategy, you will be given a three-month prescription of Truvada or Descovy. Every three to six months thereafter you will need to undergo follow-up testing and evaluations per CDC guidance:
If you choose to receive injectable PrEP, HIV testing should be repeated before each injection and whenever any other STIs are diagnosed. Apretude comes with a boxed warning to not use the medication unless a negative HIV test is confirmed. This is to reduce the risk of developing drug resistance.
How to Take and Store
Truvada and Descovy can be taken with or without food but should not be split, crushed, or chewed as this can affect the absorption of the drug.
Truvada and Descovy can be stored safely at room temperature, ideally around 77 degrees F (25 degrees C).Keep the pills in their original light-resistant container. Do not remove the moisture-retardant sachet, and never store the pills on a sunny windowsill or in your glove compartment. Discard any expired tablets.
If you miss a dose, take it as soon as you remember. If it is near the time of your next dose, skip the original dose and continue as normal. Do not double up doses.
How Effective Is PrEP in Preventing HIV
As with all drugs, Truvada, Descovy, and Apretude can cause side effects. For the most part, they will be mild and transient and usually resolve within a week or so as your body adapts to treatment. In rare cases, the drugs can cause severe side effects, often in people with pre-existing health conditions.
Common
Truvada and Descovy have slightly different mechanisms of action but many of the same side effects. Because Descovy delivers tenofovir at a significantly lower dose, the incidence of side effects is lower (between 2% and 5%) compared to Truvada (between 5% and 9%).
TruvadaFatigueNauseaDiarrheaDizzinessRash (usually mild)HeadacheInsomniaDescovyDiarrheaNauseaHeadacheFatigueStomach pain
TruvadaFatigueNauseaDiarrheaDizzinessRash (usually mild)HeadacheInsomnia
Fatigue
Nausea
Diarrhea
Dizziness
Rash (usually mild)
Headache
Insomnia
DescovyDiarrheaNauseaHeadacheFatigueStomach pain
Stomach pain
The most common side effects of Apretude include:
Severe
On rare occasions, this can lead toacute kidney failure, the symptoms of which include:
In most cases, kidney function will return to baseline levels once treatment is stopped.
Apretude carries warnings about serious or severe hypersensitivity reactions, hepatotoxicity (liver damage), and depressive disorders.That said, your healthcare provider may want to monitor your liver function. Those who experience depressive symptoms or a hypersensitivity reaction should seek prompt medical attention.
Symptoms of a hypersensitivity reaction include:
Warnings and Interactions
Both Truvada and Descovy carry aboxed warningadvising consumers that a severe flare-up ofliver symptomscan occur in people with hepatitis B following the discontinuation of treatment.Boxed warnings are the highest level of advisement from the Food and Drug Administration (FDA).
Although not contraindicated for use, Truvada and Descovy should be used with extreme caution in anyone with hepatitis B. If used,liver function testsshould be routinely repeated.Hepatitis B treatmentshould also be considered.
Truvada and Descovy are considered safe for use during pregnancy. Both animal studies and human surveillance data have shown no increase in the risk of fetal harm compared to the general population.Breastfeeding is also presumed to be safe.
A 2016 study inPLoS Medicinereported that mothers on oral PrEP only transmit miniscule amounts of tenofovir and emtricitabine through breastmilk and that nine out of 10 have no detectable traces at all.
However, due to a lack of studies, it is unclear if Apretude is safe to take while pregnant or breastfeeding.
With that said, due to a lack of long-term safety research, it is important to speak with your healthcare provider about the benefits and risks of PrEP if you are pregnant, planning to get pregnant, or breastfeeding.
How to Get Pregnant If You or Your Partner Has HIV
Drug Interactions
There are few major drug interactions associated with PrEP medication. The biggest concern with taking Truvada or Descovy is the risk of kidney-related side effects when taken with other drugs that also rely on the kidneys for excretion.
These include the following classes of drugs:
A dose adjustment or change of treatment may be needed if there is evidence of kidney impairment.
When taking Apretude, it’s best to avoid certain medications, as they can cause significantly decreased blood levels of Apretude. This can reduce the effectiveness PrEP.
These medications include:
To avoid interactions, always advise your healthcare provider about any drugs you take, whether they are prescription, over-the-counter, herbal, nutritional, or recreational.
17 Sources
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