Description: Saquinavir is a protease inhibitor that blocks the growth of Human Immunodeficiency Virus (HIV) by disrupting proteins and enzymes that will lead to immature and non-infectious HIV viruses.


Absorption: About 30% is absorbed after oral doses, but decreases to 4% when taken with food.

Distribution: 98% bound to plasma proteins. Extensively distributed into the tissues.

Metabolism: Rapidly metabolised by CYP3A4.

Excretion: Excreted mainly in the faeces. May start being secreted 13.2 hours (terminal half-life) after.


Saquinavir, used in combination with ritonavir and other HIV medications, it is used as treatment for adults (ages 16 and above) with HIV-1.  Saquinavir is not a cure for HIV infection.


Saquinavir should not be given to patients with the following conditions:

  • Congenital long QT syndrome
  • Refractory hypokalemia
  • Hypomagnesemia
  • Complete Atrioventricular (AV) block without implanted pacemakers or at risk of AV block
  • Severe hepatic impairment
  • Hypersensitivity, such as known allergic reaction to saquinavir or to any of its ingredients
  • Stevens-Johnson syndrome due to Saquinavir

How to use saquinavir

  • Dosage: Take 1000 mg of saquinavir and 100 mg or ritonavir twice daily. Both drugs should be taken at the same time.
  • Both drugs should be taken 2 hours after meals.
  • This should be taken at evenly distributed intervals to maintain the amount of drug in the body.

Availability: This is a prescription only drug.

Please see Precautions section.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

It is advised to consult your doctor or pharmacist when any of these side effect manifest.

Some people may experience worsening of a previous medical condition (such as an old infection) as their immune systems improve, or develop new conditions because their immune systems have become overactive. This reaction may occur at any time (soon after starting HIV treatment or many months later).

Tell your doctor right away if you have any serious side effects, including:

  • unexplained weight loss,
  • persistent muscle aches/weakness,
  • joint pain,
  • numbness/tingling of the hands/feet/arms/legs,
  • severe tiredness,
  • vision changes,
  • severe/persistent headaches,
  • signs of infection (such as fever, chills, trouble breathing, cough, non-healing skin sores),
  • signs of anoveractive thyroid (such as irritability, nervousness, heat intolerance, fast/pounding/irregular heartbeat, bulging eyes, unusual growth in the neck/thyroidknown as a goiter),
  • signs of a certain nerve problem known as Guillain-Barre Syndrome (such as difficulty breathing/swallowing/moving your eyes, drooping face, paralysis, slurred speech).

Seek immediate medical attention if any of these rare but serious side effects occur:

  • symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating),
  • fast/slow/irregular heartbeat,
  • severe dizziness,
  • fainting,
  • persistent nausea/vomiting,
  • stomach/abdominal pain,
  • dark urine,
  • yellowingeyes/skin.

Changes in body fat may occur while you are taking this medication (such as increased fat in the upper back and stomach areas, decreased fat in the arms and legs). The cause and long-term effects of these changes are unknown. Discuss the risks and benefits of treatment with your doctor, as well as the possible use ofexercise to reduce this side effect.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including:

  • rash,
  • itching/swelling (especially of the face/tongue/throat),
  • severe dizziness,
  • trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.



Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially QT prolongation.

  • Allergy: Before taking saquinavir, tell your doctor or pharmacist if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
  • Medical History: tell your doctor or pharmacist your medical history, especially of: lipid problems (high cholesterol or triglycerides/fats), diabetes, hemophilia, liver problems.
  • Saquinavir may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

Pregnancy Risk: Category B- No proven risk to humans. Tell your doctor if you are pregnant before using this medication.

Breastfeeding: It is unknown if this medication passes into breast milk. Because breast milk can transmit HIV, do not breast-feed.


  • Some products that may interact with this drug include: trazodone, certain benzodiazepines (midazolam, triazolam), ergot alkaloids (such as dihydroergotamine, ergonovine, ergotamine, methylergonovine), garlic supplements, ranolazine, rifamycins (such as rifampin, rifapentine), certain “statin” cholesterol drugs (simvastatin, lovastatin), other HIV medications (such as tipranavir), St. John’s wort.
  • Many drugs besides saquinavir may affect the heart rhythm (QT prolongation), including quinidine, pimozide, propafenone, cisapride, amiodarone, dofetilide, flecainide, salmeterol, among others.
  • Other medications can affect the removal of saquinavir from your body, which may affect how saquinavir works. Examples include other HIV drugs (such as indinavir, nelfinavir), among others.
  • Saquinavir can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include lurasidone, drugs to treat erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, vardenafil, tadalafil), isavuconazonium, naloxegol, rivaroxaban, suvorexant, among others.
  • This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Talk to your doctor about additional or alternative reliable forms of birth control, and always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity to decrease the risk of spreading HIV to others. Tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your hormonal birth control is not working well.


If overdose is suspected, contact a poison control center or emergency room immediately.


Do not share this medication with others.

Laboratory and/or medical tests (such as viral load, triglycerides/ cholesterol, EKG, blood sugar, T-cell counts) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Keep all medical and laboratory appointments.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.


Also marketed as

  • Invirase [ Roche ]

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