How does this medication work? What will it do for me?

Lenacapavir belongs to the class of medications called antiretroviral agents.Specifically, it is a capsid inhibitor.

This medication is used with other antiretroviral medications by adults infected with the HIV virus who have tried other combinations of medications which are no longer safe, effective, or otherwise appropriate. Lenacapavir works by preventing the HIV virus from reproducing, causing the amount of virus in the body to decrease.

HIV is the virus responsible for acquired immune deficiency syndrome (AIDS). HIV infection destroys CD4 (T) cells, which are important to the immune system. The immune system helps fight infections.

Lenacapavir does not cure AIDS and does not prevent it from being spread to others. It helps to slow down further growth or reproduction of HIV when used in combination with other medications. It also seems to slow down the destruction of the immune system.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?


Each beige, capsule-shaped, film-coated tablet, debossed with ‘GSI’ on one side of the tablet and ‘62L’ on the other side of the tablet, contains 300 mg of lenacapavir as lenacapavir sodium. Nonmedicinal ingredients: copovidone, croscarmellose sodium, iron oxide black, iron oxide red, iron oxide yellow, magnesium stearate, mannitol, microcrystalline cellulose, poloxamer 407, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

Subcutaneous Injection

Each mL of sterile, preservative-free, clear, yellow-to-brown solution with no visible particles, contains 309 mg of lenacapavir as lenacapavir sodium. Nonmedicinal ingredients: polyethylene glycol 300 and water for injection.

How should I use this medication?

Treatment with lenacapavir is a combination of subcutaneous (under the skin) injections and tablets taken by mouth.

The starting dose is 600 mg (2 x 300 mg tablets) taken by mouth on the first 2 days. This is followed by 300 mg on day 8. The tablets may be taken with or without food.

After the first 2 weeks, 927 mg (2 x 1.5 mL injections) is injected subcutaneously by your doctor on day 15 and then every 6 months after. It is important to attend your appointments for injections every 6 months. Missing injections or not receiving injections according to schedule can cause the medication to not work as well or allow the virus to change and not be treatable with lenacapavir.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.If you vomit less than 3 hours after taking the tablets, another dose should be taken right away. If more than 3 hours pass before you are sick, no extra dose is necessary. Continue with your regular dosing schedule.

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule.Do not take a double dose to make up for a missed one.

If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

It is important this medication be given exactly as recommended by your doctor. If you miss an appointment to receive lenacapavir, contact your doctor as soon as possible to reschedule your appointment.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to lenacapavir or any ingredients of the medication
  • are taking any of the following medications:
    • carbamazepine
    • phenytoin
    • rifampin
    • St. John’s wort

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • headache
  • pain, swelling, itching at the injection site
  • muscle aches and pain
  • nausea
  • rash
  • sleepiness
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Immune reconstitution inflammatory syndrome: This medication may cause immune reconstitution syndrome, where signs and symptoms of inflammation from previous infections appear. These symptoms occur soon after starting anti-HIV medication and can vary. They are thought to occur as a result of the immune system improving and being able to fight infections that have been present without symptoms (such as pneumonia, herpes or tuberculosis). Autoimmune conditions develop when the body's natural defenses (immune system) attack the tissues and organs of the body. There have been reports of autoimmune conditions such as Graves’ disease and autoimmune hepatitis developing as part of the immune reconstitution inflammatory syndrome. Report any new symptoms to your doctor immediately.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if lenacapavir passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between lenacapavir and any of the following:

  • alitretinoin
  • alpha blockers (e.g., alfuzosin, silodosin, tamsulosin)
  • anti-arrhythmics (e.g., amiodarone, disopyramide, dronedarone)
  • anti-psychotics (e.g., aripiprazole, cariprazine, clozapine, quetiapine)
  • apalutamide
  • aprepitant
  • certain benzodiazepines (e.g., alprazolam, diazepam, midazolam, triazolam)
  • bosentan
  • bromocriptine
  • buprenorphine
  • buspirone
  • calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
  • cancer medications (e.g., doxorubicin, ifosfamide, irinotecan, paclitaxel, vincristine)
  • CF transmembrane regulators (e.g., elexacaftor, ivacaftor, lumacaftor, tezacaftor)
  • clindamycin
  • colchicine
  • conivaptan
  • corticosteroids (e.g., budesonide, dexamethasone, fluticasone, methylprednisolone)
  • cyclosporine
  • darifenacin
  • digoxin
  • direct-acting oral anticoagulants (blood thinners; e.g., edoxaban, dabigatran, rivaroxaban)
  • domperidone
  • elagolix
  • elbasvir and grazoprevir
  • eletriptan
  • eliglustat
  • enzalutamide
  • eplerenone
  • ergot alkaloids (e.g., dihydroergotamine, ergonovine, ergotamine, methylergonovine)
  • erythromycin
  • everolimus
  • finerenone
  • guanfacine
  • HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine, nevirapine)
  • HIV protease inhibitors (e.g., atazanavir, lopinavir, ritonavir, tipranavir)
  • HIV integrase inhibitors (e.g., cabotegravir, dolutegravir, elvitegravir)
  • itraconazole
  • ivabradine
  • lemborexant
  • levomilnacipran
  • lomitapide
  • macitentan
  • maraviroc
  • mavacamten
  • methadone
  • mifepristone
  • modafinil
  • naloxegol
  • narcotic pain relievers (e.g., codeine, fentanyl, hydrocodone, oxycodone, tramadol)
  • orlistat
  • phenobarbital
  • phosphodiesterase-5 (PDE-5) inhibitors (e.g., sildenafil, tadalafil, vardenafil)
  • pimecrolimus
  • praziquantel
  • protein kinase inhibitors (e.g., acalabrutinib, bosutinib, ceritinib, dabrafenib, pazopanib)
  • quinine
  • ranolazine
  • rifabutin
  • rifampin
  • roflumilast
  • St. John’s wort
  • salmeterol
  • saxagliptin
  • seizure medications (e.g., carbamazepine, oxcarbazepine, phenobarbital, phenytoin)
  • sirolimus
  • solifenacin
  • ‘statin’ anti-cholesterol medications (e.g., atorvastatin, lovastatin, rosuvastatin, simvastatin)
  • tacrolimus
  • ticagrelor
  • tofacitinib
  • tolterodine
  • tolvaptan
  • topotecan
  • ulipristal
  • vilazodone
  • zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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