ISENTRESS (Raltegravir)

HIV Integrase Strand Transfer Inhibitor for Antiretroviral Therapy

Rx – Prescription Only ATC: J05AJ01 Integrase Inhibitor (INSTI)
Active Ingredient
Raltegravir (as potassium)
Available Forms
Film-coated tablets
Strengths
400 mg
Manufacturer
Merck Sharp & Dohme B.V.
Medically reviewed | Last reviewed: | Evidence level: 1A
ISENTRESS (raltegravir) is an antiretroviral medication belonging to the integrase strand transfer inhibitor (INSTI) class, used in combination with other antiretroviral agents for the treatment of HIV-1 infection. It works by blocking HIV integrase, an enzyme the virus needs to insert its genetic material into human cells, thereby reducing viral load and helping to maintain immune function.
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Quick Facts About ISENTRESS

Active Ingredient
Raltegravir
Drug Class
INSTI
ATC Code
J05AJ01
Common Uses
HIV-1 Treatment
Available Forms
Film-coated Tablet
Prescription Status
Rx Only

Key Takeaways

  • ISENTRESS (raltegravir) is an HIV integrase inhibitor that prevents the virus from integrating its DNA into human cells, reducing viral load and improving CD4 cell counts.
  • The standard adult dose is 400 mg taken orally twice daily, with or without food, and must always be used in combination with other antiretroviral medicines.
  • ISENTRESS does not cure HIV – patients should continue all prescribed antiretroviral therapy and maintain regular follow-up with their healthcare provider.
  • Aluminium/magnesium antacids and iron supplements can reduce the effectiveness of ISENTRESS and should be avoided or taken at least 2 hours apart.
  • Serious side effects are uncommon but include severe skin reactions, depression with suicidal ideation, rhabdomyolysis, and liver problems – seek medical attention immediately if these occur.

What Is ISENTRESS and What Is It Used For?

Quick Answer: ISENTRESS contains the active substance raltegravir, an integrase strand transfer inhibitor (INSTI) used to treat HIV-1 infection. It works by blocking the HIV integrase enzyme, preventing viral DNA from being inserted into human cells. ISENTRESS is always used in combination with other antiretroviral medicines.

ISENTRESS (raltegravir) is a prescription antiretroviral medication manufactured by Merck Sharp & Dohme, indicated for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. Approved by the U.S. Food and Drug Administration (FDA) in 2007 and by the European Medicines Agency (EMA) shortly thereafter, raltegravir was the first integrase strand transfer inhibitor (INSTI) to reach the market, representing a landmark in HIV therapeutics by introducing an entirely new mechanism of action.

HIV is a retrovirus that attacks the immune system, specifically CD4+ T lymphocytes (also known as T-helper cells), which play a central role in coordinating the body's defence against infections. Without treatment, HIV progressively depletes CD4 cells, eventually leading to acquired immunodeficiency syndrome (AIDS), a condition characterised by severe immune compromise, opportunistic infections, and certain malignancies. Antiretroviral therapy (ART) aims to suppress HIV replication to undetectable levels, preserve and restore immune function, and prevent transmission to others.

Mechanism of Action

Raltegravir works by selectively inhibiting HIV integrase, one of three essential enzymes that HIV uses to replicate. The HIV replication cycle involves several steps: the virus enters a CD4 cell, reverse transcriptase converts the viral RNA into DNA, and integrase then catalyses the insertion (or “integration”) of this newly formed viral DNA into the host cell’s genome. Once integrated, the viral DNA uses the host cell’s machinery to produce new viral particles.

By blocking the integrase enzyme at the strand transfer step, raltegravir prevents HIV DNA from being inserted into human chromosomes. This effectively halts the viral replication cycle, reducing the amount of HIV in the blood (known as the “viral load”) and allowing CD4 cell numbers to recover. The INSTI class, to which raltegravir belongs, is now considered one of the cornerstones of modern ART regimens, as recommended by the World Health Organization (WHO) and the U.S. Department of Health and Human Services (DHHS) guidelines.

Clinical Indications

ISENTRESS is indicated for the treatment of HIV-1 infection in adults, adolescents, and children weighing at least 25 kg, always in combination with other antiretroviral agents. It is used in both treatment-naïve patients (those who have never received ART) and treatment-experienced patients (those who have previously been on other antiretroviral regimens). According to the European AIDS Clinical Society (EACS) 2024 Guidelines, integrase inhibitors including raltegravir remain a recommended component of first-line and salvage therapy regimens.

It is important to understand that ISENTRESS does not cure HIV infection. Even when viral load is suppressed to undetectable levels, HIV persists in latent reservoirs within the body. Patients must continue taking their prescribed antiretroviral regimen consistently to maintain viral suppression, preserve immune function, and prevent the development of drug resistance. ISENTRESS is one component of a multi-drug regimen and should never be used as monotherapy.

What Should You Know Before Taking ISENTRESS?

Quick Answer: Do not take ISENTRESS if you are allergic to raltegravir or any other ingredient. Tell your doctor about any history of depression, liver disease, or muscle problems before starting treatment. ISENTRESS does not cure HIV, and patients may still develop infections.

Contraindications

ISENTRESS is contraindicated in patients with known hypersensitivity to raltegravir or to any of the excipients in the formulation. Although true allergic reactions to raltegravir are uncommon, severe and potentially life-threatening hypersensitivity reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported in post-marketing surveillance. If a hypersensitivity reaction is suspected, ISENTRESS should be discontinued immediately and appropriate medical treatment initiated.

Warnings and Precautions

Before starting ISENTRESS, patients should discuss their complete medical history with their healthcare provider. Several important warnings and precautions apply to the use of this medication:

Important Warning – ISENTRESS Does Not Cure HIV ISENTRESS helps control HIV infection but does not eliminate the virus from the body. You may continue to develop opportunistic infections and other complications associated with HIV disease. Continue to see your doctor regularly and take all prescribed medications.

Mental health concerns: Depression, including suicidal thoughts and suicidal behaviour, has been reported in some patients taking ISENTRESS, particularly those with a pre-existing history of psychiatric illness. Patients and caregivers should be alert to changes in mood, feelings of hopelessness, or any unusual behavioural changes, and report these to their healthcare provider promptly. The risk-benefit assessment should be carefully considered in patients with a history of depression or other mental health disorders.

Bone problems (osteonecrosis): Some patients receiving combination antiretroviral therapy may develop osteonecrosis, a condition in which bone tissue dies due to loss of blood supply. Risk factors include prolonged exposure to combination ART, corticosteroid use, alcohol consumption, severe immunosuppression, and higher body mass index (BMI). Symptoms include joint stiffness, pain (particularly in the hip, knee, and shoulder), and difficulty with movement. Patients experiencing any of these symptoms should inform their doctor immediately.

Liver problems: Patients with pre-existing hepatic impairment, including hepatitis B or hepatitis C co-infection, should inform their doctor before starting ISENTRESS. Hepatic function should be evaluated before initiating treatment and monitored periodically during therapy. Cases of hepatitis, hepatic failure, and elevated liver enzymes have been reported in patients taking raltegravir, though a causal relationship has not always been established.

Immune reconstitution inflammatory syndrome (IRIS): When ART is initiated in patients with advanced HIV disease who have had previous opportunistic infections, inflammatory reactions to these pre-existing infections may occur shortly after treatment begins. This immune reconstitution inflammatory syndrome (IRIS) results from the recovering immune system mounting an inflammatory response against pathogens that were previously present without obvious symptoms. Symptoms may include fever, malaise, and organ-specific inflammation. Additionally, autoimmune disorders (conditions in which the immune system attacks healthy tissue) may also emerge months after ART initiation, including Graves’ disease, polymyositis, and Guillain-Barré syndrome.

Muscle problems: Rhabdomyolysis (severe muscle breakdown) and myopathy (muscle disease) have been reported in patients taking ISENTRESS. Patients should be advised to contact their doctor immediately if they experience unexplained muscle pain, tenderness, or weakness, especially if accompanied by dark urine or fever. Creatine kinase (CK) levels should be monitored if clinically indicated.

Skin reactions: Severe and potentially life-threatening skin reactions, including SJS and drug reaction with eosinophilia and systemic symptoms (DRESS), have been reported rarely with raltegravir use. Patients should be instructed to discontinue ISENTRESS and seek immediate medical attention if they develop a skin rash, especially if it is accompanied by fever, blistering, mucosal involvement, or systemic symptoms.

Pregnancy and Breastfeeding

The safety of ISENTRESS during pregnancy requires careful consideration. While raltegravir crosses the placenta and has been detected in cord blood, clinical data from pregnancy registries and observational studies have generally been reassuring. The DHHS Perinatal HIV Guidelines include raltegravir as an option for use during pregnancy, particularly when rapid viral load reduction is needed (such as late presentation in pregnancy), because of its rapid onset of action.

Breastfeeding is not recommended for women living with HIV, regardless of viral load or antiretroviral treatment status, because HIV can be transmitted to the infant through breast milk. In settings where safe alternatives to breast milk are available, women with HIV should avoid breastfeeding. If breastfeeding is being considered, patients should discuss the risks and benefits thoroughly with their healthcare provider.

Lactose and Sodium Content ISENTRESS 400 mg film-coated tablets contain lactose monohydrate. Patients with rare hereditary conditions of galactose intolerance, total lactase deficiency, or glucose-galactose malabsorption should not take this medicine. Each tablet contains less than 1 mmol (23 mg) of sodium, meaning it is essentially sodium-free.

Driving and Operating Machinery

Dizziness has been reported in some patients taking ISENTRESS. If you experience dizziness after taking this medication, you should avoid driving, operating machinery, or engaging in activities that require alertness until you know how the medicine affects you.

How Does ISENTRESS Interact with Other Drugs?

Quick Answer: ISENTRESS may interact with aluminium/magnesium antacids (which reduce its effectiveness), iron supplements (take at least 2 hours apart), and rifampicin (which significantly lowers raltegravir levels). Always inform your doctor of all medicines you take, including over-the-counter products and supplements.

Drug interactions with ISENTRESS are an important consideration for ensuring therapeutic efficacy and patient safety. Raltegravir is primarily metabolised by uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1)-mediated glucuronidation, rather than through the cytochrome P450 (CYP450) enzyme system. This metabolic pathway means that raltegravir has a relatively low potential for interactions with CYP450-mediated drugs compared to many other antiretrovirals. However, several clinically significant interactions do exist.

The interactions listed below are the most clinically relevant. Patients should always inform their healthcare provider about all medications they are taking, including prescription drugs, over-the-counter medicines, herbal remedies, and dietary supplements.

Key Drug Interactions with ISENTRESS
Interacting Drug Effect Recommendation
Rifampicin Significantly reduces raltegravir plasma levels by inducing UGT1A1 glucuronidation Doctor may increase ISENTRESS dose; close monitoring required
Aluminium/Magnesium antacids Substantially reduce raltegravir absorption through chelation Not recommended for co-administration; use alternative antacids
Iron supplements May reduce raltegravir absorption through chelation Take iron supplements at least 2 hours before or after ISENTRESS
Atazanavir Increases raltegravir plasma levels via UGT1A1 inhibition Generally no dose adjustment required; monitor for side effects
Tipranavir/ritonavir Reduces raltegravir plasma levels Clinical significance uncertain; use with caution and monitoring
Carbamazepine, Phenytoin, Phenobarbital Strong UGT1A1 inducers that may reduce raltegravir exposure Use with caution; consider alternative anticonvulsants
St. John’s Wort (Hypericum perforatum) May reduce raltegravir plasma levels via UGT induction Avoid concomitant use

Major Interactions

Rifampicin is one of the most clinically important drug interactions with ISENTRESS. Rifampicin is a potent inducer of UGT1A1 and can reduce raltegravir plasma concentrations by approximately 40–60%. Since rifampicin is widely used in the treatment of tuberculosis (TB) – a common co-infection in people living with HIV, particularly in resource-limited settings – this interaction has significant clinical relevance. When co-administration with rifampicin is necessary, the DHHS guidelines recommend doubling the raltegravir dose to 800 mg twice daily, although data supporting this approach are limited and close virological monitoring is advised.

Aluminium and magnesium-containing antacids can substantially reduce the oral bioavailability of raltegravir through a chelation mechanism, in which metal cations bind to the drug and reduce its absorption from the gastrointestinal tract. The clinical significance of this interaction is well established, and co-administration with these antacids is not recommended. Patients requiring acid suppression therapy should discuss alternatives with their healthcare provider; proton pump inhibitors (PPIs) and H2-receptor antagonists do not appear to have a clinically significant interaction with raltegravir.

Minor Interactions

Iron supplements may reduce the absorption of raltegravir through a similar chelation mechanism. To minimise this interaction, patients should be advised to take iron-containing products at least two hours before or after taking ISENTRESS. Calcium supplements and multivitamins containing divalent cations should also be separated from raltegravir dosing.

Atazanavir, an HIV protease inhibitor, can increase raltegravir plasma levels because it inhibits UGT1A1. In clinical studies, co-administration of atazanavir/ritonavir with raltegravir increased raltegravir AUC by approximately 41–72%. Despite this increase, dose adjustment is not routinely required, as raltegravir has a wide therapeutic index. However, patients should be monitored for potential increases in side effects.

What Is the Correct Dosage of ISENTRESS?

Quick Answer: The recommended dose for adults and adolescents/children weighing at least 25 kg is one 400 mg film-coated tablet taken by mouth twice daily, with or without food. ISENTRESS must always be used in combination with other antiretroviral medicines.

ISENTRESS should always be taken exactly as prescribed by the healthcare provider. It must be used as part of a combination antiretroviral regimen and should never be taken alone (monotherapy). The dosing schedule and proper administration are critical for maintaining adequate drug levels in the blood, ensuring viral suppression, and preventing the development of drug resistance.

Adults

Adult Dosage

The recommended dose is 400 mg (one tablet) taken orally twice daily. Tablets should be swallowed whole and not chewed, crushed, or split, as this may alter drug levels in the body. ISENTRESS can be taken with or without food.

Adherence to the twice-daily dosing schedule is essential for maintaining therapeutic drug concentrations and preventing viral rebound. Clinical trials have demonstrated that raltegravir 400 mg twice daily achieves rapid and sustained viral suppression in both treatment-naïve and treatment-experienced patients. The STARTMRK trial, a landmark phase III study, showed that raltegravir-based regimens achieved non-inferior efficacy compared to efavirenz-based regimens at 5 years of follow-up, with a generally favourable safety and tolerability profile.

Alternative Formulations Available ISENTRESS is also available as a 600 mg tablet (taken as two 600 mg tablets once daily), a chewable tablet, and granules for oral suspension. Patients should not switch between formulations without consulting their healthcare provider, as the different formulations are not interchangeable on a milligram-per-milligram basis due to differences in bioavailability.

Children and Adolescents

Paediatric Dosage (Weight ≥ 25 kg)

The recommended dose is 400 mg (one tablet) taken orally twice daily, the same as the adult dose. This dose applies to adolescents and children weighing at least 25 kg.

For children weighing less than 25 kg, alternative formulations (chewable tablets or oral suspension) are available with weight-based dosing. The choice of formulation and dose should be determined by the prescribing physician based on the child’s weight and ability to swallow tablets. ISENTRESS has been studied in paediatric populations in the IMPAACT P1066 trial, which demonstrated safety and efficacy in children from 4 weeks of age.

Elderly Patients

Elderly Dosage

There are no specific dose adjustments required for elderly patients. However, caution is advised due to the greater frequency of co-morbidities, polypharmacy, and decreased hepatic or renal function in this population.

Clinical experience with raltegravir in patients over 65 years of age is limited. As with all antiretroviral therapy in older adults, prescribers should be attentive to potential drug interactions with concomitant medications, consider the patient’s overall renal and hepatic function, and monitor for adverse effects more closely.

Missed Dose

If you miss a dose of ISENTRESS, take it as soon as you remember. However, if it is almost time for your next scheduled 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. Consistent adherence to the prescribed dosing schedule is crucial, as even brief interruptions in antiretroviral therapy can lead to viral rebound and increase the risk of developing drug-resistant HIV.

Overdose

In the event of an overdose, do not take more tablets than recommended by your healthcare provider. There is no specific antidote for raltegravir overdose. Management should consist of general supportive measures, including monitoring of vital signs and observation of the patient’s clinical status. Raltegravir is unlikely to be significantly removed by dialysis due to its high protein binding. If you suspect an overdose, contact your doctor or local poison control centre immediately.

Do Not Stop Treatment Without Medical Advice It is critically important that you continue taking all HIV medicines as prescribed. Do not stop, skip doses, or change your dosage without first consulting your healthcare provider. Interruptions in treatment, even brief ones, can allow the virus to multiply rapidly, potentially leading to drug resistance that makes ISENTRESS and similar medications less effective in the future. Always ensure you have a sufficient supply of medication and do not allow your prescription to run out.

What Are the Side Effects of ISENTRESS?

Quick Answer: Common side effects include headache, insomnia, nausea, dizziness, fatigue, and diarrhoea. Serious but uncommon side effects include depression (with suicidal ideation), severe skin reactions, rhabdomyolysis, and liver problems. Seek immediate medical attention for any severe or unusual symptoms.

Like all medicines, ISENTRESS can cause side effects, although not everyone will experience them. Most side effects associated with raltegravir are mild to moderate in severity and tend to improve or resolve as the body adjusts to the medication. However, some side effects can be serious and require immediate medical attention. The frequency categories below are based on data from clinical trials and post-marketing surveillance.

Common Side Effects

May affect up to 1 in 10 people

  • Decreased appetite
  • Difficulty sleeping (insomnia), abnormal dreams, nightmares
  • Behavioural changes, feelings of deep sadness and worthlessness (depression)
  • Dizziness, headache
  • Vertigo (spinning sensation)
  • Abdominal pain, bloating, diarrhoea, excessive gas, nausea, vomiting
  • Indigestion, belching
  • Various types of rash (occurs more frequently when combined with darunavir)
  • Tiredness, unusual fatigue or weakness, fever
  • Elevated liver enzymes, abnormal white blood cells in blood tests
  • Elevated blood lipids and pancreatic/salivary enzymes

Uncommon Side Effects

May affect up to 1 in 100 people

  • Herpes infections including shingles
  • Anaemia, including iron-deficiency anaemia
  • Signs and symptoms of infection or inflammation
  • Mental health disorders, suicidal intent or attempt
  • Gastric inflammation (gastritis), liver inflammation (hepatitis), liver failure
  • Allergic rash, certain kidney problems
  • Hair follicle infection, influenza, upper respiratory tract infection
  • Warts, swollen lymph nodes
  • Allergic reaction, increased appetite, diabetes, high blood sugar
  • Excessive thirst, significant weight loss, body fat redistribution
  • Anxiety, confusion, mood changes, panic attacks
  • Memory loss, attention deficit, taste changes, increased drowsiness
  • Migraine, numbness or weakness in arms/legs, tingling, tremor
  • Visual disturbances, tinnitus (ringing in ears)
  • Palpitations, slow/fast/irregular heartbeat
  • Hot flushes, high blood pressure
  • Hoarse voice, nosebleeds, nasal congestion
  • Constipation, dry mouth, heartburn, pancreatitis
  • Acne, unusual hair loss, skin redness, excessive sweating, night sweats
  • Joint pain, back pain, bone pain, muscle weakness, neck pain
  • Kidney stones, increased nighttime urination, erectile dysfunction
  • Breast enlargement in males, menopausal symptoms
  • Chest discomfort, chills, facial swelling, general malaise
  • Low white blood cell count, low platelet count
  • Decreased kidney function in blood tests, weight gain

Serious Side Effects (Uncommon but Severe)

Seek immediate medical attention

  • Severe skin reactions (Stevens-Johnson syndrome, DRESS syndrome)
  • Rhabdomyolysis (severe muscle breakdown with dark urine)
  • Liver failure with jaundice
  • Severe allergic/hypersensitivity reactions
  • Suicidal thoughts or behaviour
  • Immune reconstitution inflammatory syndrome (IRIS)
  • Autoimmune disorders (e.g., Guillain-Barré syndrome, Graves’ disease)
  • Osteonecrosis (bone tissue death)

Additional Side Effects in Children and Adolescents

In paediatric clinical trials, hyperactivity has been reported as an additional side effect in children and adolescents taking ISENTRESS. The overall safety profile of raltegravir in paediatric patients is generally consistent with that observed in adults, though healthcare providers should monitor for age-specific behavioural and developmental effects.

Immune Reconstitution Inflammatory Syndrome

In patients with advanced HIV infection and severely compromised immune function, the initiation of ART (including ISENTRESS) can trigger immune reconstitution inflammatory syndrome (IRIS). As the immune system recovers, it may mount inflammatory responses against previously dormant opportunistic infections – such as Mycobacterium avium complex, cytomegalovirus retinitis, Pneumocystis jirovecii pneumonia, or tuberculosis – causing symptoms of infection or inflammation to appear or worsen. IRIS typically occurs within the first few weeks to months of ART initiation and usually responds well to treatment of the underlying opportunistic infection and, in severe cases, short courses of corticosteroids.

Reporting Side Effects It is important to report suspected side effects after a medicine has been authorised. This allows continuous monitoring of the medicine’s benefit-risk balance. Healthcare professionals and patients are encouraged to report any suspected adverse reactions through their national reporting system (e.g., the FDA MedWatch programme in the United States, the Yellow Card Scheme in the United Kingdom, or the EMA’s EudraVigilance system in Europe).

How Should You Store ISENTRESS?

Quick Answer: Store ISENTRESS at room temperature. Keep the bottle tightly closed with the desiccant inside to protect from moisture. Do not swallow the desiccant. Store out of sight and reach of children.

Proper storage of ISENTRESS is essential to maintain the stability and efficacy of the medication. The following storage guidelines should be observed:

  • Temperature: No special temperature storage requirements. Store at room temperature.
  • Moisture protection: The bottle should be kept tightly closed with the desiccant (moisture-absorbing sachet) inside. ISENTRESS is sensitive to moisture, and exposure to humidity can affect the tablet’s integrity.
  • Desiccant: Do not remove or swallow the desiccant sachet contained within the bottle.
  • Child safety: Keep this medicine out of the sight and reach of children.
  • Expiry date: Do not use after the expiry date stated on the bottle and carton (marked “EXP”). The expiry date refers to the last day of that month.
  • Disposal: Do not dispose of medicines via wastewater or household waste. Ask your pharmacist about how to properly dispose of medicines that are no longer needed, in order to protect the environment.

What Does ISENTRESS Contain?

Quick Answer: Each 400 mg film-coated tablet contains raltegravir (as potassium salt) as the active ingredient, along with inactive ingredients including lactose monohydrate and various excipients. The tablet is oval, pink, and marked with “227” on one side.

Understanding the composition of ISENTRESS is important for patients with known allergies or intolerances to specific excipients. The following table provides a detailed breakdown of the tablet’s composition:

ISENTRESS 400 mg Film-coated Tablet Composition
Component Function
Raltegravir (as potassium) – 400 mg Active substance (integrase inhibitor)
Lactose monohydrate Filler/diluent
Microcrystalline cellulose Filler/binder
Anhydrous dibasic calcium phosphate Diluent
Hypromellose 2208 Binder
Poloxamer 407 Surfactant/solubiliser
Sodium stearyl fumarate Lubricant
Magnesium stearate Lubricant
Polyvinyl alcohol, titanium dioxide, PEG 3350, talc, red iron oxide, black iron oxide Film-coating components

Appearance and Packaging

The ISENTRESS 400 mg film-coated tablet is oval-shaped, pink in colour, and debossed with “227” on one side. The tablets are supplied in bottles containing a desiccant sachet for moisture protection. Two pack sizes are available: packs containing 1 bottle of 60 tablets, and multipacks comprising 3 bottles of 60 tablets each (180 tablets total). Not all pack sizes may be marketed in all countries.

Frequently Asked Questions About ISENTRESS

ISENTRESS (raltegravir) is used to treat HIV-1 infection in adults, adolescents, and children weighing at least 25 kg. It belongs to the integrase strand transfer inhibitor (INSTI) class and works by blocking the HIV integrase enzyme, which the virus needs to insert its genetic material into human cells. ISENTRESS is always used in combination with other antiretroviral medicines as part of a complete HIV treatment regimen. It does not cure HIV but helps control the infection by reducing the viral load and allowing the immune system to recover.

The most common side effects of ISENTRESS include headache, insomnia (difficulty sleeping), abnormal dreams, dizziness, nausea, diarrhoea, abdominal pain, fatigue, and skin rash. These side effects are generally mild to moderate and often improve as the body adjusts to the medication. Elevated liver enzymes and blood lipid levels may also be detected in blood tests. If any side effect becomes severe or persistent, contact your healthcare provider.

Aluminium and magnesium-containing antacids should not be taken with ISENTRESS, as they significantly reduce its absorption and effectiveness through a chelation mechanism. If you require acid suppression, your doctor can recommend alternatives such as proton pump inhibitors or H2 blockers, which do not significantly interact with raltegravir. Iron supplements should be taken at least 2 hours before or after ISENTRESS to minimise the risk of reduced absorption. Always discuss your medications with your healthcare provider.

No, ISENTRESS does not cure HIV infection. It is an important part of combination antiretroviral therapy (ART) that helps control the virus by reducing the amount of HIV in the blood (viral load) and increasing CD4 cell counts, which strengthens the immune system. Even when the viral load becomes undetectable, HIV remains in the body in latent reservoirs. Stopping treatment can lead to viral rebound and the potential development of drug resistance. Patients should continue taking ISENTRESS as prescribed and maintain regular follow-up appointments with their healthcare provider.

The use of ISENTRESS during pregnancy should be decided by your healthcare provider based on a careful assessment of the benefits and risks. Raltegravir is included as an option in the DHHS Perinatal HIV Guidelines, particularly when rapid viral suppression is needed in late pregnancy. However, breastfeeding is not recommended for women living with HIV, as the virus can be transmitted to the infant through breast milk. If you are pregnant, planning to become pregnant, or breastfeeding, discuss your treatment options with your healthcare provider before taking any medication.

If you miss a dose of ISENTRESS, take it as soon as you remember. If it is nearly time for your next dose, skip the missed dose and return to your normal schedule. Never take a double dose to compensate. Consistent adherence is vital – even brief gaps in treatment can allow HIV to multiply and potentially develop resistance to your medications. If you frequently forget doses, discuss adherence strategies with your healthcare provider, such as using pill organisers or setting reminders.

References

This article is based on peer-reviewed medical literature, regulatory documents, and international clinical practice guidelines. All medical claims are supported by evidence level 1A (systematic reviews and meta-analyses of randomized controlled trials) where available.

  1. European Medicines Agency (EMA). ISENTRESS – Summary of Product Characteristics. Available at: www.ema.europa.eu/en/medicines/human/EPAR/isentress.
  2. U.S. Food and Drug Administration (FDA). ISENTRESS (raltegravir) Prescribing Information. Merck Sharp & Dohme Corp.
  3. World Health Organization (WHO). Consolidated Guidelines on HIV Prevention, Testing, Treatment, Service Delivery and Monitoring: Recommendations for a Public Health Approach. Geneva: WHO; 2021.
  4. Panel on Antiretroviral Guidelines for Adults and Adolescents (DHHS). Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV. Department of Health and Human Services. Updated 2024.
  5. European AIDS Clinical Society (EACS). EACS Guidelines, Version 12.0, October 2023. Available at: www.eacsociety.org/guidelines.
  6. Lennox JL, DeJesus E, Rockstroh JK, et al. Long-term efficacy and safety of raltegravir-based therapy in treatment-naïve patients: 5-year results of the STARTMRK study. J Acquir Immune Defic Syndr. 2014;65(4):453–462.
  7. Steigbigel RT, Cooper DA, Teppler H, et al. Long-term efficacy and safety of raltegravir combined with optimized background therapy in treatment-experienced patients with drug-resistant HIV infection: BENCHMRK combined 156-week results. Clin Infect Dis. 2010;50(4):605–612.
  8. Nachega JB, Parienti JJ, Uthman OA, et al. Lower pill burden and once-daily antiretroviral treatment regimens for HIV infection: A meta-analysis of randomized controlled trials. Clin Infect Dis. 2014;58(9):1297–1307.
  9. Panel on Treatment of Pregnant Women with HIV Infection and Prevention of Perinatal Transmission (DHHS). Recommendations for the Use of Antiretroviral Drugs in Pregnant Women with HIV Infection. Updated 2024.
  10. British HIV Association (BHIVA). Guidelines for the Treatment of HIV-1-Positive Adults with Antiretroviral Therapy. 2023.

Editorial Team

This article has been written and reviewed by the iMedic Medical Editorial Team, comprising licensed physicians with specialisation in infectious disease, virology, and clinical pharmacology. Our editorial process follows strict evidence-based principles.

Medical Writing

iMedic Medical Editorial Team – specialists in infectious disease, HIV medicine, and clinical pharmacology with documented academic backgrounds and clinical experience.

Medical Review

iMedic Medical Review Board – independent panel of medical experts who review all content according to international guidelines (WHO, DHHS, EACS, BHIVA) and the GRADE evidence framework.

Last medical review: . Next scheduled review: . All content is reviewed at least every 6 months to ensure accuracy and alignment with the latest clinical evidence.